National 

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Safety Board

Washington, D.C.

National Transportation

Safety Board

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NTSB

Permit No. G-200

Aircraft Accident Report

Controlled Flight Into Terrain

Era Aviation

Sikorsky S-76A++, N579EH

Gulf of Mexico, About 70 Nautical Miles 

South-Southeast of

Scholes International Airport, Galveston, Texas

March 23, 2004

NTSB/AAR-06/02

PB2006-910402 National Transportation Safety Board

Notation 7646B 490 LíEnfant Plaza, S.W.

Adopted March 7, 2006 Washington, D.C. 20594

E PLUR IBUS UNUM

NATIONAL TRA S PORTATION

B OAR D

SAFE T Y

N
National Transportation Safety Board. 2006. Controlled Flight Into Terrain, Era Aviation, Sikorsky

S-76A++, N579EH, Gulf of Mexico, About 70 Nautical Miles South-Southeast of Scholes International

Airport, Galveston, Texas, March 23, 2004. Aircraft Accident Report NTSB/AAR-06/02.

Washington, DC.

Abstract: This report explains the accident involving an Era Aviation Sikorsky S-76A++ helicopter,

N579EH, which crashed into the Gulf of Mexico about 70 nautical miles south-southeast of

Scholes International Airport (GLS), Galveston, Texas. Safety issues discussed in this report

focus on terrain awareness and warning systems for helicopters, flight control system training,

flight-tracking technology for low-flying aircraft in the Gulf of Mexico, and preflight testing and

maintenance checks for cockpit voice recorders. Safety recommendations concerning these issues

are addressed to the Federal Aviation Administration.

The National Transportation Safety Board is an independent Federal agency dedicated to promoting aviation, railroad, highway, marine,

pipeline, and hazardous materials safety. Established in 1967, the agency is mandated by Congress through the Independent Safety Board

Act of 1974 to investigate transportation accidents, determine the probable causes of the accidents, issue safety recommendations, study

transportation safety issues, and evaluate the safety effectiveness of government agencies involved in transportation. The Safety Board

makes public its actions and decisions through accident reports, safety studies, special investigation reports, safety recommendations, and

statistical reviews.

Recent publications are available in their entirety on the Web at <http://www.ntsb.gov>. Other information about available publications also

may be obtained from the Web site or by contacting:

National Transportation Safety Board

Records Management Division, CIO-40

490 LíEnfant Plaza, S.W.

Washington, D.C. 20594

(800) 877-6799 or (202) 314-6551

Safety Board publications may be purchased, by individual copy or by subscription, from the National Technical Information Service. To

purchase this publication, order report number PB2006-910402 from:

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5285 Port Royal Road

Springfield, Virginia 22161

(800) 553-6847 or (703) 605-6000

The Independent Safety Board Act, as codified at 49 U.S.C. Section 1154(b), precludes the admission into evidence or use of Board reports

related to an incident or accident in a civil action for damages resulting from a matter mentioned in the report. 
iii Aircraft Accident Report

Contents

Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii

1. Factual Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 History of Flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 Injuries to Persons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.3 Damage to Aircraft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.4 Other Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.5 Personnel Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.5.1 The Captain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.5.2 The Copilot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.6 Aircraft Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.6.1 Main Rotor and Tail Rotor Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.6.2 Powerplants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.6.3 Flight Control Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.6.3.1 Cyclic, Collective, and Tail Rotor Pedal Control Systems . . . . . . . . . . . . . . . . . . 8

1.6.3.2 SPZ-7000 Dual Digital Automatic Flight Control System . . . . . . . . . . . . . . . . . . 8

1.6.3.2.1 Autopilots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

1.6.3.2.2 Flight Directors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

1.6.3.2.3 Coupling Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

1.6.3.3 Electronic Flight Information System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.6.4 Maintenance Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1.6.5 Previous Flights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

1.7 Meteorological Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

1.8 Aids to Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1.9 Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1.10 Airport Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1.11 Flight Recorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1.11.1 Cockpit Voice Recorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1.11.2 Flight Data Recorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

1.12 Wreckage and Impact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

1.12.1 Main Rotor and Tail Rotor Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

1.12.2 Powerplants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

1.12.3 Landing Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

1.13 Medical and Pathological Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1.14 Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1.15 Survival Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1.16 Tests and Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

1.16.1 Cockpit Voice Recorder Study. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

1.16.2 Actuator Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

1.17 Organizational and Management Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

1.17.1 Era Aviation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Contents iv Aircraft Accident Report

1.17.1.1 S-76A Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

1.17.1.2 Ground and Flight Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

1.17.1.3 Visual Flight Rules Flight Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

1.17.1.4 Federal Aviation Administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

1.18 Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

1.18.1 Flight Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

1.18.2 Gulf of Mexico Helicopter Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

1.18.3 Automatic Dependent SurveillanceñBroadcast Technology . . . . . . . . . . . . . . . . . . 31

1.18.4 Controlled Flight Into Terrain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

1.18.5 Comparison of SPZ-7000 and SPZ-7600 Dual Digital 

Automatic Flight Control Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

1.18.5.1 Federal Aviation Administration SPZ-7000 Evaluation . . . . . . . . . . . . . . . . . . . 37

1.18.6 Previous Flight Recorder Safety Recommendations . . . . . . . . . . . . . . . . . . . . . . . . 38

1.18.6.1 Safety Recommendation A-02-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

1.18.6.2 Safety Recommendations A-06-17 and A-06-18. . . . . . . . . . . . . . . . . . . . . . . . . 39

2. Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

2.2 Accident Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

2.2.1 Accident Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

2.2.2 Indications of Descent and Proximity to the Water . . . . . . . . . . . . . . . . . . . . . . . . . 42

2.2.3 Human Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

2.2.3.1 Flight Crew Experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

2.2.3.2 Crew Coordination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

2.2.3.3 Use of Automated Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

2.3 Cockpit Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

2.3.1 Terrain Awareness and Warning System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

2.3.2 Dual Digital Automatic Flight Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

2.4 Tracking of Gulf of Mexico Helicopter Flights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

2.5 Lack of Adequate Cockpit Voice Recorder Information 

for This Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

2.6 Lack of Flight Data Recorder Information for Helicopter Operations . . . . . . . . . . . . . . 56

3. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

3.1 Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

3.2 Probable Cause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

4. Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

4.1 New Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

4.2 Additional Recommendations Resulting From This 

Accident Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

4.3 Previously Issued Recommendation Classified 

in This Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

5. Appendixes

A: Investigation and Public Hearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

B: Cockpit Voice Recorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

C: Flight Simulation Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

D: Gulf of Mexico Helicopter Accident Data March 

 2000 Through February 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
v Aircraft Accident Report

Figures

1. Location of DDAFCS Components and Indications in the

Accident Helicopterís Cockpit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2. Autopilot Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3. Flight Director Mode Selector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4. Electronic Attitude Director Indicator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5. Indications of Descent on the Attitude Direction Indicator. . . . . . . . . . . . . . . . . . . . . . . . . . 27

6. Altitude Alert Light. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

7. SPZ-7000 Dual-Cue Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

8. SPZ-7000 Single-Cue Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

9. Indications of Descent in the Accident Helicopterís Cockpit . . . . . . . . . . . . . . . . . . . . . . . . 43
vi Aircraft Accident Report

Abbreviations

ADI attitude direction indicator

ADS-B automatic dependent surveillanceñbroadcast

agl above ground level

ALT altitude

ALT PRE altitude preselect

AP autopilot

ASOS automated surface observing system

ASR airport surveillance radar

ATT attitude

BEA Bureau díEnquÍtes et díAnalyses pour la SÈcuritÈ de

líAviation Civile

CAM cockpit area microphone

CFIT controlled flight into terrain

CFR Code of Federal Regulations

CLTV collective

CPL couple

CPLT FD copilot flight director

CRM crew resource management

CVR cockpit voice recorder

DAFCS digital automatic flight control system

DCPL decouple

DDAFCS dual digital automatic flight control system

DFDR digital flight data recorder

DH decision height

EFIS electronic flight instrument system

EMS emergency medical services

FAA Federal Aviation Administration
Abbreviations vii Aircraft Accident Report

FD flight director

FDR flight data recorder

FOU Port Fourchon, Louisiana

fpm feet per minute

GLS Scholes International Airport

GPS global positioning system

GPWS ground proximity warning system 

HDG heading

HSAC Helicopter Safety Advisory Conference

HSI horizontal situation indicator

IAS indicated airspeed

IFR instrument flight rules

LCH Lake Charles Regional Airport

METAR meteorological aerodrome report

msl mean sea level

NAV navigation

nm nautical mile

NWS National Weather Service

PIC pilot in command

POI principal operations inspector

RA radar altitude

S/N serial number

SAS stability augmentation system

SBY standby

TAWS terrain awareness and warning system

UTC coordinated universal time

VFR visual flight rules

VHF very high frequency

VMC visual meteorological conditions

VS vertical speed

VSI vertical slope indicator
viii Aircraft Accident Report

Executive Summary

On March 23, 2004, about 1918:34 central standard time, an Era Aviation

Sikorsky S-76A++ helicopter, N579EH, crashed into the Gulf of Mexico about 70 nautical

miles south-southeast of Scholes International Airport (GLS), Galveston, Texas. The

helicopter was transporting eight oil service personnel to the Transocean, Inc., drilling

ship Discoverer Spirit, which was en route to a location about 180 miles south-southeast

of GLS. The captain, copilot, and eight passengers aboard the helicopter were killed, and

the helicopter was destroyed by impact forces. The flight was operating under the

provisions of 14 Code of Federal Regulations Part 135 on a visual flight rules flight plan.

Night visual meteorological conditions prevailed at the time of the accident. 

The National Transportation Safety Board determines that the probable cause of

this accident was the flight crewís failure to identify and arrest the helicopterís descent for

undetermined reasons, which resulted in controlled flight into terrain.

The safety issues discussed in this report focus on terrain awareness and warning

systems for helicopters, flight control system training, flight-tracking technology for

low-flying aircraft in the Gulf of Mexico, and preflight testing and maintenance checks for

cockpit voice recorders. Safety recommendations concerning these issues are addressed

to the Federal Aviation Administration.
1 Aircraft Accident Report

1. Factual Information

1.1 History of Flight

On March 23, 2004, about 1918:34 central standard time,1 an Era Aviation

Sikorsky S-76A++ helicopter, N579EH, crashed into the Gulf of Mexico about

70 nautical miles (nm) south-southeast of Scholes International Airport (GLS),

Galveston, Texas. The helicopter was transporting eight oil service personnel to the

Transocean, Inc., drilling ship Discoverer Spirit, which was en route to a location about

180 miles south-southeast of GLS. The captain, copilot, and eight passengers aboard the

helicopter were killed, and the helicopter was destroyed by impact forces. The flight

was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 135

on a visual flight rules (VFR) flight plan.2 Night visual meteorological conditions

(VMC) prevailed at the time of the accident.

The accident helicopter had been operated out of Era Aviationís flight and

maintenance facility at Port Fourchon (FOU), Louisiana, as part of its contract with

Union Oil Company of California for day and night aviation support operations. On

March 22, 2004, two Era Aviation pilots repositioned the accident helicopter from FOU

to GLS because the Discoverer Spirit was going to be operating from a location in the

Gulf of Mexico that was closer to GLS. On March 22, the copilot drove his personal

vehicle from FOU to GLS. On March 23, the captain drove his personal vehicle from his

home to GLS.3

An Era Aviation captain stated that he saw the accident captain briefing the

accident copilot and both pilots obtaining weather information from the Internet. The

Era Aviation captain also stated that he saw the accident captain, in the right pilot seat,4

taxi the helicopter to the site where the copilot and passengers would board.5 The Era

Aviation captain further stated that one box of cargo and the passengersí baggage were

loaded on the helicopter.

1 All times in this report are central standard time based on a 24-hour clock.

2 This flight plan was maintained by the company and was followed by the company dispatcher. The

flight plan was not filed with the Federal Aviation Administration. See section 1.17.1.3 for more

information.

3 The accident captain, who normally worked the day shift, had been off duty during the previous

5 days but was aware that he would need to replace the on-duty night captain because of a scheduling

conflict. During a postaccident interview, the captainís wife stated that he had changed his sleep pattern

during the previous 72 hours so that he could handle the job requirements for this work assignment.

4 The captain normally occupies the right seat in a helicopter.

5 Each passenger viewed a videotaped safety briefing before boarding the helicopter.
Factual Information 2 Aircraft Accident Report

A dispatcher located at Era Aviationís Gulf Coast headquarters was

responsible for communicating by radio with the accident flight and entering

information about the flight in a computerized log after each radio transmission. The

dispatcherís records showed that the helicopter departed GLS at 1845 on an estimated

45-minute flight to an en route refueling stop at High Island A-557.6 The records also

showed that the helicopter had 2 hours of fuel on board at the time of departure. The

cockpit voice recorder (CVR) recording began at 1847:42. The recording was mostly

unintelligible, but conversational-tone voices were discernible during parts of the

recording.7

Radar data from the Airport Surveillance Radar-9 (ASR-9) at the George Bush

Intercontinental Airport in Houston, Texas,8

 showed that the helicopter flew on a

south-southeasterly course after takeoff and climbed to 1,800 feet mean sea level

(msl). The radar data also showed that the helicopter remained at 1,800 feet msl until

about 1858:10 and then started to descend at a rate of about 300 feet per minute (fpm).

A radar return that was received about 1900:21 showed that the helicopter was at an

altitude of 1,100 feet msl and that its rate of descent was about 250 fpm. No radar

returns were received after that time because the helicopter was no longer within the

range of radar coverage.9

 At that point, the helicopter was about 35 nm

south-southeast of GLS. 

According to company procedures, the flight crew was responsible for providing

the dispatcher with a position report every 15 minutes.10 During its 1914 position report,11

the flight crew told the dispatcher that the helicopter had enough fuel on board (1.6 hours)

to continue directly to the Discoverer Spirit.

12 Also, the flight crew asked the dispatcher to

provide updated coordinates to the Discoverer Spirit.

13 The dispatcher received no further

6 A lighted fixed oil and gas platform with refueling capability was located in U.S. Gulf Coast VFR

Aeronautical Chart reference area High Island A-557, which was about 80 nm south-southeast of GLS and

slightly to the east of a direct course from GLS to the reported location of the Discoverer Spirit (U.S. Gulf

Coast VFR Aeronautical Chart reference area Alaminos Canyon 738). 

7 See section 1.11.1 for more information.

8 The National Transportation Safety Board obtained these data from the U.S. Air Force 84th Radar

Evaluation Squadron.

9 ASRs are designed to provide short-range radar coverage within the general vicinity of an airport.

The maximum radar coverage is about 60 nm. At the time of the last radar return, the accident helicopter was

about 58 nm southeast of the Houston ASR-9 radar site.

10 The standard position report at the time of the accident consisted of the helicopterís distance to its

destination and the amount of fuel on board the aircraft. After the accident, the position reports also included

the helicopterís altitude.

11 The flight crew had provided two previous position reportsóat 1850 and 1902. Both reports

indicated that the helicopter would stop at High Island A-557 for refueling.

12 The CVR recording captured the copilot stating, in part, ìwe [have] enough to ah fly to ah spirit.î

13 The Discoverer Spirit was lighted, and its helideck had refueling capability.
Factual Information 3 Aircraft Accident Report

communications from the flight crew.14 About 1918:25, the CVR recorded the sound of

decreasing background noise. The CVR stopped recording about 1918:34.

The dispatcherís records showed that, at 1923, she tried to make radio contact with

the flight crew to provide updated coordinates to the Discoverer Spirit but received no

response from the crew. The records also showed that, at 1931, 1934, 1946,15 and 2008,

the dispatcher continued to try to make radio contact with the helicopter. The 1931 entry

indicated that the dispatcher would call the Discoverer Spirit to see if someone aboard the

ship could make radio contact with the helicopter,16 and the 1934 entry indicated that

someone aboard the ship was trying to contact the helicopter.

During a postaccident interview, the dispatcher stated that, in her communications

with the flight crew, everything sounded normal with no strange background noises. Also,

the dispatcher received no emergency or distress calls from the helicopter. 

Seven vessels (from the U.S. Coast Guard and Union Oil) and nine aircraft (from

the Coast Guard; Era Aviation; Petroleum Helicopters, Inc. [PHI]; and Evergreen

Helicopters) were activated for search and rescue operations.17 Pilots aboard these aircraft

observed debris floating near the area that was believed to be the location of the helicopter

after its last communication with the dispatcher. The helicopter wreckage was located

about 70 nm south-southeast of GLS and 10 nm northwest of High Island A-557 at a depth

of about 186 feet.

14 If a flight crew position report is not called in within 15 minutes of the last report, the helicopterís tail

number on the flight plan line (which is displayed on the dispatcherís screen) turns from white to yellow. If

the position report is still not called in within the next 5 minutes, the entire flight plan line turns to yellow. If

the flight crew has not called in to close out or extend its flight plan at the estimated time of arrival for the

helicopterís destination, the entire flight plan line turns red.

15 The dispatcherís records indicated two entries for 1946. 

16 The Discoverer Spirit had two-way FM radio communications capability with the helicopter. 

17 According to an Era Aviation vice president, five aircraft were dispatched on the night of the accident 

for search and rescue operations: a helicopter from PHI was deployed from GLS about 2150; an Era

helicopter was deployed from Houma, Louisiana, about 2209; two U.S. Coast Guard aircraft were deployed

about 2210; and a helicopter from Evergreen Helicopters was deployed from GLS sometime before 2230.

By 0515 on March 24, 2004, four vessels had joined the search and rescue operations. By 1000 on March 24,

three additional vessels and four additional aircraft had joined the search and rescue operations. 
Factual Information 4 Aircraft Accident Report

1.2 Injuries to Persons

Table 1. Injury chart.

1.3 Damage to Aircraft

The helicopter was destroyed as a result of impact forces with the water.

1.4 Other Damage

No other damage was reported.

1.5 Personnel Information

1.5.1 The Captain

The captain, age 50, held an airline transport pilot certificate with a

rotorcraft-helicopter rating. The captain also held a Federal Aviation Administration

(FAA) first-class medical certificate dated May 12, 2003, with a limitation that required

him to wear lenses to correct for distant vision and possess glasses to correct for near

vision.

The captain served in the U.S. Army from July 1977 to August 1988, during which

time he graduated from Army flight training and became an Army pilot (December 1980).

From October 1988 to October 1999, the captain served in the U.S. Coast Guard as a pilot.

The captain was hired by Era Aviation in November 1999.

According to company records, the captain had accumulated 7,288 hours total

flying time, including 5,323 hours as pilot-in-command (PIC) of multiengine helicopters,

1,489 hours aboard S-76 helicopters, and 1,028 hours at night. Company records also

showed that the captain had accumulated 3,913 hours total flying time in the Gulf of

Mexico. Further, the captain had flown in the Gulf of Mexico 389, 64, and 32 hours in the

Injuries Flight Crew Cabin Crew Passengers Other Total

Fatal 2 0 8 0 10 

Serious 0 0 0 0 0

Minor 0 0 0 0 0

None 0 0 0 0 0

Total 2 0 8 0 10 
Factual Information 5 Aircraft Accident Report

12 months, 90 days, and 30 days, respectively, before the accident. The 32-hour flight

time (for the 30 days before the accident) included about 3 hours at night.

Between March 1, 2003, and March 23, 2004, the captain accumulated 344 total

flight hours (764 flights) in Era Aviation S-76A helicopters, 335 hours of which were

flown during the day and 9 hours of which were flown at night. Of his 344 total

flight hours, the captain flew 276 hours in S-76As with an analog flight control system

and 68 hours in S-76As with a digital flight control system.18 Of the 68 hours in a digital

S-76A, 1 hour was flown at night, and 17 hours (43 flights) were flown in the accident

helicopter (with 0.4 houróthe accident flightóat night).

The captain completed initial ground and flight training for the S-76A on

November 17, 1999; a flight check on January 30, 2004, in an analog S-76A; recurrent

instrument training on February 18, 2003; and recurrent ground training on February 26,

2004. The captain was also rated in the Bell 212/412 helicopter. FAA records indicated no

accident or incident history or enforcement action, and a search of the National Driver

Register indicated no record of driverís license suspension or revocation.

The captainís wife reported that he was in good health and that his financial

situation was good. She also reported that he was not taking any prescription or

nonprescription medications. In addition, she stated that he did not smoke and that he

consumed alcohol occasionally at home.

The captain normally worked the day shift (0530 to 1930). The captain was on

duty from March 4 to 17, 2004,19 and was off duty from March 18 to March 22, 2004.

Before the captain went off duty, he was made aware that he would need to cover the

upcoming night shift. On March 23, 2004, the captain drove his personal vehicle from his

home to GLS (about 30 miles) and reported for duty about 1700. The accident flight was

his first flight. The accident flight was also the first one that paired the captain and the

copilot.

The captainís wife stated that, during the 72 hours before the accident, his

activities included doing yard work and ìstuff around the house.î She also stated that, on

the morning of the accident, the captain slept until 1100. The captainís wife further stated

that she spoke with him during the afternoon and indicated that he sounded fine. 

An Era Aviation captain (who was formerly the companyís chief pilot) stated that

the accident captain was always an extremely conscientious pilot and that he trusted him

implicitly. The captain also stated that he never heard any complaints about the accident

captain.

18 All Era Aviation S-76A pilots are trained to fly both the analog and digital flight control system

versions of the helicopter. The accident helicopter had a digital flight control system. See section 1.17.1.1

for information about the S-76A analog flight control system and sections 1.6.3.2 and 1.17.1.1 for

information about the S-76A digital flight control system.

19 Era pilots were generally scheduled to be on duty for 2 weeks and then off for 2 weeks.
Factual Information 6 Aircraft Accident Report

1.5.2 The Copilot

The copilot, age 46, held a commercial pilotís license with a rotorcraft-helicopter

rating. The copilot also held an FAA first-class medical certificate dated March 15, 2004,

with a limitation that required him to wear corrective lenses while exercising the

privileges of the certificate. 

The copilot received flight training at Versatile Aviation, Ardmore, Oklahoma,

from August 1999 to April 2000, during which time he received his flight instructor

certificate (October 1999). From April 2000 to March 2001, the copilot was a flight

instructor at Versatile Aviation. From March to June 2001, he was a line pilot at Kenai

Helicopters, Grand Canyon, Arizona. The copilot was hired by Era Aviation in

August 2001.

According to company records, the copilot had accumulated 1,941 hours total

flying time, including 1,371 hours as ìPIC Helicopters,î 534 hours as ìSIC

(second-in-command) Helicopters,î 483 hours aboard S-76 helicopters, and 63 hours at

night. Company records also showed that the copilot had accumulated 1,027 hours total

flying time in the Gulf of Mexico. Further, the copilot had flown in the Gulf of Mexico

678, 14, and 4.5 hours in the 12 months, 90 days, and 30 days, respectively, before the

accident. The 4.5-hour flight time (for the 30 days before the accident) included 3.6 hours

at night.

Between March 1, 2003, and March 23, 2004, the copilot accumulated 451 total

flight hours (608 flights) in Era Aviation S-76A helicopters, 434 hours of which were

flown during the day and 17 hours of which were flown at night. Of his 451 total flight

hours, the copilot flew 314 hours in S-76As with a digital flight control system and

137 hours in S-76As with an analog flight control system. Of the 314 hours in a digital

S-76A, 9 hours were flown at night, and 79 hours (97 flights) were flown in the accident

helicopter (with 5.4 hours flown at night between January 20 and March 23, 2004). 

The copilot completed initial ground and flight training for the S-76A on

December 12, 2002, and his first S-76A flight occurred on February 11, 2003. The copilot

completed recurrent ground training on February 12, 2004; recurrent instrument training

on February 17, 2004; and a flight check on February 20, 2004, in the accident helicopter

(a digital S-76A). The copilot was also rated in the Bell 212/412 helicopter. FAA records

indicated no accident or incident history or enforcement action, and a search of the

National Driver Register indicated no record of driverís license suspension or revocation.

The copilot had been assigned to the night shift during his previous several duty

periods, the last of which ended on March 3, 2004. The copilot had been off duty from

March 4 to 17, 2004. He began his most recent duty schedule on March 17, 2004. From

March 18 to 20, the copilot attended training (ground school for the Boelkow 105

helicopter)20 at Lake Charles Regional Airport (LCH), Lake Charles, Lousiana, from 0800

20 Era Aviation training records showed that the copilot was in the process of upgrading to PIC of the

Boelkow 105 helicopter, which has analog instrumentation and no autopilots or flight directors.
Factual Information 7 Aircraft Accident Report

to 1700. On March 21, the copilot drove his car from LCH to FOU (about 230 miles); on

March 22, he drove his car from FOU to GLS (400 miles). The copilot returned to the

night shift on March 23, and the accident flight was his first flight during the duty period.

An Era Aviation captain who shared an apartment with the copilot when they were

scheduled for duty indicated that he and the copilot would arrive at work about 1630 and

that the night shift would begin about 1700 and end about 0500. The captain also indicated

that he and the copilot would typically go to sleep immediately after their shift ended and

that they would wake up about 1400. The captain described their schedules as ìeat, sleep,

work, eat, sleep, work for 14 days and then you go home.î

The Era Aviation captain stated that the copilotís health was excellent and that his

financial situation was unremarkable. The captain also stated that, on the day of the

accident, the copilot was not suffering from a cold or allergies, and his mood was fine.

Another Era Aviation captain stated that the copilot smoked and that he consumed alcohol

only outside of work. 

The Era Aviation captain who shared an apartment with the copilot when they

were on duty stated that the copilot did not have any problems flying the S-76A and that

he was interested in moving up in the company. The captain had previously flown

11 hours with the copilot and stated that the copilot had volunteered to do all of the flying.

The captain further stated that he knew of no complaints about the copilotís flying abilities

and that he had not experienced any emergencies or other problems during previous

flights with the copilot. In addition, the Era Aviation captain who was formerly the

companyís chief pilot stated that the copilot was very keen and very conscientious, and

another Era Aviation captain stated that the copilot was extremely competent.

1.6 Aircraft Information

The accident helicopter, a Sikorsky S-76A++, serial number (S/N) 760274, was a

transport-category, twin-engine, single main rotor helicopter that was configured to carry

2 pilots and up to 12 passengers. Aircraft records showed that the helicopter was

manufactured in 1984 and was issued an export airworthiness certificate to Court Aviation

Company of South Africa. Aircraft records also showed that the helicopter was transferred

to Era Aviation in June 2001, at which time the helicopter received a new registration

number, and that the helicopter received its U.S. airworthiness certificate in August 2001.

At the time of the accident, the helicopter had accumulated 10,075 total flight hours and

2,882 total cycles.21

1.6.1 Main Rotor and Tail Rotor Systems

The S-76A main rotor system provides the aerodynamic forces that make the

helicopter fly. The main rotor system includes the main rotor drive shaft, which is attached

21 An aircraft cycle is one complete takeoff and landing sequence.
Factual Information 8 Aircraft Accident Report

to a main transmission gearbox and a main rotor head,22 and four main rotor blades, which

are installed on a main rotor hub. Three hydraulic actuators (forward, aft, and lateral)

control the movement of the swashplate, which changes the pitch angle of the main rotor

blades.

The S-76A tail rotor system is used to control torque (that is, the tendency of

helicopters with a single main rotor system to turn in the opposite direction of the main

rotor rotation). The tail rotor system includes a tail rotor drive shaft with five sections that

run through the tail cone, an intermediate gearbox, a tail rotor gearbox, and four tail rotor

blades. The tail rotor drive shaft is attached to the main transmission gearbox. The tail

rotor blades are integrated into two paddles so that each paddle has one blade on each end.

1.6.2 Powerplants

Aircraft records showed that the accident helicopter was initially installed with

two Rolls Royce (formerly Allison) 250-C30 engines. The records also showed that, on

June 19, 1998, Keystone Helicopters of West Chester, Pennsylvania, installed two

Turbomeca Arriel 1S1 engines aboard the helicopter. (The designation for S-76A

helicopters that are equipped with Arriel 1S1 engines is S-76A++.) At the time of the

accident, the left engine, S/N 3015, had accumulated 4,519 hours and 7,633 cycles, and

the right engine, S/N 15109, had accumulated 2,052 hours and 3,161 cycles.

1.6.3 Flight Control Systems

1.6.3.1 Cyclic, Collective, and Tail Rotor Pedal Control Systems

The accident helicopter was equipped with cyclic, collective, and tail rotor pedal

control systems. Moving the cyclic forward or aft causes the helicopter to pitch up or

down;23 moving the cyclic left or right causes the helicopter to roll in the commanded

direction.24 Raising or lowering the collective results in a simultaneous increase or

decrease, respectively, in the lift produced by the main rotor blades. Moving the tail rotor

pedals (which are similar to airplane rudder pedals) positions the tail rotor blades to cause

the helicopter to yaw.25 Either pilot can control the cyclic, collective, and tail rotor pedal

control systems.

1.6.3.2 SPZ-7000 Dual Digital Automatic Flight Control System

The accident helicopter was equipped with a Honeywell SPZ-7000 Dual Digital

Automatic Flight Control System (DDAFCS), which was specifically designed for

helicopters to provide full four-axis (longitudinal, lateral, vertical, and yaw) flight control.

The DDAFCS includes the autopilots (see section 1.6.3.2.1); flight directors (see

22 The main rotor head has four spindles and four blade dampers.

23 Pitch is the movement of the helicopter about its lateral (side to side) axis.

24 Roll is the movement of the helicopter about its longitudinal (nose to tail) axis.

25 Yaw is the movement of the helicopter about its vertical axis.
Factual Information 9 Aircraft Accident Report

section 1.6.3.2.2); flight control computers, which provide all computations for autopilot

and flight director operation; air data components,26 which provide the flight control

computers with information about the helicopterís airspeed, altitude above sea level,

vertical speed, and radar altitude (that is, the helicopterís altitude above the surface);27 and

an autotrim system. Figure 1 is a preaccident photograph of the helicopterís cockpit that

shows the location of DDAFCS components and indications.

26 The air data components include an air data command display known as the AL-300.

27 Radar altitude is computed by the radar altimeter system. The radar altimeter receiver/transmitter box

sends a signal to the ground through a transmitter antenna. The receiver/transmitter box receives an echo

through a receiver antenna. The receiver/transmitter box then measures the phase or time difference between

the two signals and transmits this information to the cockpit in terms of feet above the ground. Radar altitude

is also referred to as radio altitude.

Figure 1. Location of DDAFCS Components and Indications in the Accident 

Helicopterís Cockpit

Source: Era Aviation. 

 1. Air data command display (AL-300)

 2. Captain’s electronic flight information system (EFIS) displays

 3. Captain’s digital automatic flight control system (DAFCS) caution panel 

 and decouple (DCPL) indication

 4. Captain’s flight director mode selector

 5. Autopilot controller

 6. Copilot’s flight director mode selector

 7. Copilot's EFIS displays

 8. Copilot’s DAFCS caution panel and DCPL indication

 9. Copilot’s flight director indication 

10. DAFCS indication

2 3 4

7 6 5

8 9 10 1
Factual Information 10 Aircraft Accident Report

1.6.3.2.1 Autopilots

Dual autopilot systems provide stability to the S-76 helicopter through a stability

augmentation system (SAS) and an attitude retention mode (ATT). Both SAS and ATT

modes provide heading hold,28 yaw damping and autotrim, and automatic turn coordination.

The SAS mode provides short-term rate damping during manual flight and is selected when

extensive maneuvering is required; this mode is commonly used during the initial and final

phases of flight and while hovering. The ATT mode provides pitch and roll attitude

retention, through the autotrim system, during manual flight. Thus, after an in-flight

disturbance, the helicopter will automatically return to the reference attitude. The ATT mode

engages automatically when either autopilot is selected. Upon initial ATT mode

engagement, the helicopterís reference attitude is its current attitude. The reference attitude

can be reset by pressing a button on the cyclic. 

Only one of the stability modes (SAS or ATT) can be engaged at a time. The autopilot

controller is used to engage SAS or ATT and autopilots No. 1 and No. 2 (AP1 and AP2).

(Autopilot coupling, which refers to automatic flight, is discussed in section 1.6.3.2.3.) When

selected, the SAS button illuminates in amber, the ATT button illuminates in green, and the

AP1 and AP2 buttons illuminate in green and indicate ìON.î Figure 2 shows the autopilot

controller, which is located on the center pedestal (as shown by number 5 in figure 1).

1.6.3.2.2 Flight Directors

The flight directors assist pilots in maintaining a specified flightpath or attitude

through the presentation of command cues29 on the attitude director indicators (ADI).30

28 SAS provides heading hold when the helicopterís airspeed is below 60 knots; ATT provides heading

hold at all airspeeds.

Figure 2. Autopilot Controller

Note: The ìFD1/2î button allows the pilot to select flight director 1 or 2 (as discussed in section 1.6.3.2.2). The ìCPLî

button automatically illuminates when the autopilot and the flight director are coupled (as discussed in section 1.6.3.2.3).

The ìHOVî button allows the pilot to select the hover mode. The ìCOLLî button allows the pilot to select either the flight

director or the radar altimeter to provide collective commands. The ìTESTî button allows the pilot to test the autopilots

before they are engaged. 

Source: Honeywell.

29 Additional information about command cues appears in section 1.18.5.

30 The ADIs are the top screens of the EFIS displays (as shown by numbers 2 and 7 in figure 1).

Information about the ADIs appears in section 1.6.3.3.

SAS ATT ON FD RAD ON

AP1

SAS/ATT TEST COLL CPL

AP2 HOV FD 1/2

ON ON ON 1 2
Factual Information 11 Aircraft Accident Report

Flight director 1 is used when the left seat pilot is flying the helicopter, and flight

director 2 is used when the right seat pilot is flying the helicopter. Flight director selection

is made on the autopilot controller (see figure 2) with the FD1/2 button, which illuminates

in white and indicates ì1î or ì2î depending on which flight director was selected. (Each

press of the FD1/2 button alternates between flight directors 1 and 2.) When FD1 is

selected, a ìCPLT FDî light illuminates in green on the caution/advisory panel on the

front instrument panel (see number 9 in figure 1). No light illuminates on the

caution/advisory panel when FD2 is selected.

The command cues that are presented on the ADIs generally correspond to the

selected flight director modes, which include heading (HDG), vertical speed (VS), altitude

(ALT), navigation (NAV), altitude preselect (ALT PRE), and standby (SBY). Figure 3

shows the flight director mode selector, which is located on the front instrument panel (as

shown by numbers 4 and 6 in figure 1).

1.6.3.2.3 Coupling Function

For the SPZ-7000 DDAFCS, whenever a flight director mode is selected, FD1 or

FD2 becomes automatically coupled to the autopilot as long as AP1, AP2, and the

autopilotís ATT mode are engaged. Coupling allows the flight directorís computed pitch

and roll attitude corrections to be input to the autopilot so that the pilot does not have to

manually control the helicopter according to the command cues on the ADIs. The CPL

button on the autopilot controller (see figure 2) automatically illuminates in green and

Figure 3. Flight Director Mode Selector

Note: Other buttons on the flight director mode selector are ILS, instrument landing system mode; DECEL, deceleration

mode; VOR APR, very high frequency omnidirectional range approach mode; IAS, indicated airspeed mode; BC,

instrument landing system backcourse; and GA, go-around mode. 

Source: Honeywell. 

HDG

ON ON ON

ARM CAP ARM ARM

ARM CAP

ARM CAP

ARM CAP

GS

ON

ON ON

CAP

NAV

VOR APR IAS ALT PRE

BC SBY GA

ILS DECEL

VS ALT
Factual Information 12 Aircraft Accident Report

indicates ìONî when the autopilot and the flight director are coupled.31 The primary

method to decouple the autopilot and the flight director is by pushing the CPL button.32

Once decoupling occurs, the pilot is required to fly the helicopter manually. No aural

warning occurs when the autopilot and flight director become decoupled.

During normal operations, the illumination, or absence of illumination, of the CPL

button is the only direct annunciation of the status of the couple function.33 Because of its

location on the center pedestal, the CPL button is out of the pilotsí routine instrument

scan. During abnormal operations,34 a DCPL (decouple) warning indicator on the pilotsí

digital automatic flight control system (DAFCS) caution panels35 illuminates in amber

whenever the autopilot and flight director are not coupled for an activated mode.36 The

DAFCS caution panels are located in front of the pilots above the barometric altimeters

(as shown by numbers 3 and 8 in figure 1).

1.6.3.3 Electronic Flight Information System

The DDAFCS interfaces with an analog electronic flight information system

(EFIS), which receives inputs from attitude, heading, navigation, and flight director

sources to provide information to four cathode-ray tube flat-panel screens on the front

instrument panel (two for each pilot position). The top screens are the electronic ADIs,

which display pitch and roll attitudes via a blue and brown sphere that moves with respect

to a stationary aircraft symbol to display actual pitch and roll attitudes. The bottom screens

are the electronic horizontal situation indicators (HSI), which display the helicopterís

position in relation to the selected course and heading or actual heading.

The ADIs display numerous items in addition to the attitude sphere and command

cues (if selected). For example, the ADIs annunciate, at the top of the display, the flight

director mode (or modes) that has been selected. The ADIs also annunciate the radar altitude

31 During postaccident interviews, Era Aviation S-76A pilots indicated that the CPL button had to be

selected to couple the autopilot and flight director. However, pressing the CPL button actually decouples the

two systems.

32 An alternate method of decoupling is by pressing a quick release button on the bottom of the cyclic.

When this button is pressed, the CPL buttonís ON annunciation no longer illuminates, all modes selected on

the flight director mode selector disengage and return to standby, and command cues are no longer shown on

the ADI.

33 Indirect indications of the couple function are shown by course deviation on the ADIs and the

horizontal situation indicators and changes displayed on mechanical instruments, such as the barometric

altimeter, heading indicator, and vertical speed indicator.

34 Abnormal refers to an aircraft-induced decouple resulting from a malfunction of a sensor, which

causes an activated mode to decouple.

35 The DAFCS caution panels annunciate malfunctions related to the autopilot and coupling function.

The panel has three other warning indications besides DCPL: AP1, AP2, and CLTV (collective). The AP1

and AP2 warnings illuminate in amber when an autopilot failure, a hardover, or an oscillatory malfunction

occurs. The CLTV warning illuminates in amber when the collective trim switch is off or the collective

command limit has been exceeded.

36 Whenever any DAFCS caution panel warning is annunciated, the abbreviation ìDAFCSî illuminates

in amber on the caution/advisory panel (see number 10 in figure 1), and a red ìMASTER WARNINGî light

under the glareshield panel (the top rim portion of the front instrument panel) illuminates.
Factual Information 13 Aircraft Accident Report

in blue in the lower right corner37 and the pilot-selected decision height38 in blue in the lower

left corner.39 Figure 4 shows an electronic ADI and its various displays. The ADIs do not

show which flight director has been selected or whether it has been coupled to the autopilot.

1.6.4 Maintenance Records

Maintenance records for the accident helicopter indicated that it was being

maintained in accordance with an FAA-approved Continuous Airworthiness Maintenance

Program. This program consists of regularly scheduled inspections, parts replacements,

and tests and uses a computer database to track an aircraftís flight and maintenance

activities. The database also tracks the requirements for inspections, overhauls, retirement

of components, airworthiness directives, service bulletins, and survival equipment.

37 The radar altitude readouts, which range from -20 to 2,500 feet, appear numerically in 10-foot

increments between 200 and 2,500 feet and 5-foot increments below 200 feet.

38 The decision height is the height at which a decision must be made either to continue the approach or

execute a missed approach. The decision height is selected in 5-foot increments from 0 to 200 feet and

10-foot increments from 200 to 990 feet. The decision height knob is located on a display controller on the

center pedestal.

39 According to Era Aviationís Operations Manual (Operating Procedures section, chapter 5, page 11,

dated December 23, 2002), ìan operating radar altimeter is required for all night flights and for all day

flights when the ceiling is less than 400 feet and/or the visibility is less than 2 miles. The DH [decision

height] shall be set to 200 feet.î

Figure 4. Electronic Attitude Director Indicator

Source: Honeywell.

200 DH 140 RA

 HDG

Roll

attitude

pointer

Roll

scale

Flight director

mode annunciation

Flight director

mode annunciation

Pitch and roll

command bars

Decision height

box and 

indication

Aircraft 

symbol

Radar 

altitude 

display

Rising 

runway

Decision 

height

display

Pitch

scale

20 20

10 10

10 10

20 20

DH

ALTP
Factual Information 14 Aircraft Accident Report

On March 22, 2004, a main rotor blade inspection (performed every 300 hours)

was conducted at LCH. On March 23, 2004 (the accident date), a tail rotor spar inspection

(performed every 25 hours) was conducted at GLS. The aircraft maintenance log for

March 22 and 23, 2004, indicated ìpreflight inspection made this date, A/C [aircraft]

deemed Airworthy and Satisfactory for operational flight.î

The last recorded flight control maintenance action occurred on March 15 and 16,

2004. The maintenance action involved replacing the helicopterís trim relay assembly (a

minimum equipment list [MEL] item)40 because of an inoperative relay, performing an

operational check, and clearing the helicopter for flight. The replacement of the

helicopterís trim relay assembly was the final corrective action for a series of discrepancies

concerning the flight director that occurred between March 9 and March 16, 2004.41

1.6.5 Previous Flights

On March 22, 2004, two Era Aviation pilots repositioned the accident helicopter

from FOU to GLS. During a postaccident interview, the copilot who repositioned the

accident helicopter stated that the captain of the repositioning flight tested the DDAFCS

before departure and found it to be functioning properly. This copilot also stated that the

DDAFCS was engaged during the flight and that the flight director ALT mode had been

selected. Further, the copilot stated that he did not recall anything being wrong with the

helicopter during the flight and that the helicopter performed as expected.

On March 23, 2004, the helicopter flew 5.4 hours before the accident flight with no

reported discrepancies. The captain of these flights stated, during a postaccident interview,

that the helicopter flew well and experienced no problems. The DDAFCS was used during

this flight.

1.7 Meteorological Information

Weather observations at GLS are made by an automated surface observing system

(ASOS), which is maintained by the National Weather Service (NWS). The ASOS records

40 According to the FAA, an MEL is an inventory of instruments and equipment that may legally be

inoperative with the specific conditions under which an aircraft may be flown with such items inoperative.

41 On March 9, 2004, the aircraft maintenance log indicated that the copilotís flight director did not hold

altitude when the navigation and heading modes were selected and that the helicopter pitched nose down and

descended when the collective was lowered manually. The log also indicated that, to correct this

discrepancy, the pilotís and copilotís flight control computers were swapped; however, because this action

only transferred the problem to the pilotís side, the flight control computers were switched back, and the

copilotís computer was replaced. An operational check was performed, but the copilotís flight director still

responded as before. On March 10, 2004, the copilotís flight director was placed on the MEL. To address the

problem, the pitch trim actuator was replaced on March 12, 2004. A ground check of the pitch trim actuator

was then performed, which was successful. On March 15, 2004, the trim relay assembly was replaced

because of an inoperative relay. On March 16, 2004, paperwork was updated to indicate that the trim relay

assembly had been replaced and that this corrective action had cleared the discrepancy. As a result, the flight

director was removed from the MEL, and the helicopter was cleared for flight.
Factual Information 15 Aircraft Accident Report

continuous information on wind speed and direction, cloud cover, temperature,

precipitation, and visibility42 and transmits an official meteorological aerodrome report

(known as a METAR) each hour in coordinated universal time (UTC). (Central standard

time is 6 hours behind UTC time.) The 0052Z43 METAR (1852 local time), which was

issued 7 minutes after the helicopter departed from GLS, indicated the following: winds

110o at 11 knots, visibility 10 miles, few clouds at 2,800 feet, overcast at 4,000 feet,

temperature 19o C (66o F), dew point 16o C (61o F), and altimeter setting 30.25 inches of

mercury.

The NWS surface analysis chart for 0000Z (1800 local time) showed a ridge of high

pressure extending over the area with winds from the east-southeast at 10 to 20 knots. Buoy

reports indicated winds from the east-southeast to southeast at 17 to 21 knots. Satellite

imagery depicted no cumulonimbus clouds or thunderstorms over the region but depicted a

scattered to broken layer of low stratiform clouds over the Gulf of Mexico south of GLS.

The Galveston weather service radar identified no weather echoes near the accident site.

Sunset occurred about 1833, and the end of evening civil twilight44 was about

1856, which was 11 minutes after the flightís departure from GLS. According to the U.S.

Naval Observatory, 8 percent of the moon disk was illuminated at the time of the accident.

1.8 Aids to Navigation

Not applicable.

1.9 Communications

During a postaccident interview, the Era Aviation dispatcher reported that the

flight crew called her after takeoff. The dispatcher stated that she was able to hear the

pilots but that they were unable to hear her, even after they changed frequencies. The

dispatcher thought that the reason for this lack of communication was because the

helicopter had just taken off and had not reached a sufficient altitude. No other

communications problems between the dispatcher and the flight crew were reported.

No audio record of the conversations between the dispatcher and the accident

flight crew was available.45 Such conversations are normally recorded on a very high

42 Cloud cover is expressed in feet above ground level. Visibility is expressed in statute miles.

43 The ìZî designation that follows the time in a weather observation stands for Zulu, which indicates

UTC time. 

44 The U.S. Naval Observatory explains evening civil twilight as follows: ìto end in the evening when

the center of the Sun is geometrically 6 degrees below the horizon. This is the limit at which twilight

illumination is sufficient, under good weather conditions, for terrestrial objects to be clearly

distinguished...Complete darkness, however...begins sometime after the end of evening civil twilight.î

45 The only record of the communications between the dispatcher and the pilots was a three-page

printout containing nine entries (as described in section 1.1). The printout was generated from the

dispatcherís computerized log at Era Aviationís Gulf Coast headquarters. 
Factual Information 16 Aircraft Accident Report

frequency (VHF) tape deck system in Era Aviationís Gulf Coast headquarters operations

center; however, on the night of the accident, the tape deck system was not working.46

1.10 Airport Information

Not applicable. 

1.11 Flight Recorders

1.11.1 Cockpit Voice Recorder

The helicopter was equipped with an L-3 Communications solid-state model

FA2100 CVR, S/N 118739. The exterior of the CVR did not appear to have any heat or

structural damage, but it had been submerged in salt water. The CVR memory module was

removed, restacked using dry components, and installed on a Safety Board FA2100 CVR

chassis in the Boardís audio laboratory. The CVR audio data was successfully

downloaded.

The CVR recording contained four channels of audio data. The first audio channel,

which was not required by Federal regulations, did not contain any usable audio

information. The second and third audio channels recorded information from the pilot and

copilot stations but did not contain any usable audio information. The fourth audio

channel contained poor quality47 audio information from the cockpit area microphone

(CAM). A transcript was prepared of the entire 30-minute 52-second digital recording (see

appendix B), but most of the recording was obscured by a high level of background noise.

The manufacturer of the CVR evaluated the main chassis to determine if the CVR

was functioning properly at the time of the accident. The evaluation determined that the

CVR was operating within its design specifications.

The Safety Board evaluated the internal communications system units from the

pilot (captain) and copilot stations. On the left side of each unit was a white notched

switch, labeled model 105/103, that could slide up or down to be set in the top (105) or the

bottom (103) positions. According to CVR installation documentation provided by Era

46 During a postaccident interview, Era Aviationís director of operations stated that the system had been

unhooked 1 or 2 days earlier for the installation of new furniture but that the system was accidentally not

hooked up again. Once the problem was discovered, the system was hooked up again. In addition, a

computer-based backup system for audio recordings was installed a few weeks after the accident.

47 The Safety Board rates the quality of CVR recordings according to a five-category scale: excellent,

good, fair, poor, and unusable. Poor quality CVR information is characterized by the following traits:

extraordinary means had to be used to make some of the crew conversations intelligible. The transcript that

was developed may indicate fragmented phrases and conversations and may indicate extensive passages

where conversations were missing or unintelligible. This type of recording is usually caused by a

combination of a high cockpit noise level with a low voice signal (poor signal-to-noise ratio) or by a

mechanical or electrical failure of the CVR system that severely distorts or obscures the audio information.
Factual Information 17 Aircraft Accident Report

Aviation, the switches determine the internal configuration for the CVR output, and

failure to set the switches to the correct model position results in a lack of audio input to

the respective CVR channels. The helicopterís CVR installation required that the switches

be set to the bottom (103) position, but the switches were found set to the top (105)

position. (These switches were not visible to the pilots.) After this accident, Era Aviation

checked the CVRs installed on its remaining S-76A helicopters and found that the

switches were set to the correct position. 

According to FAA Form 337, ìMajor Repair and Alteration,î the installation of

the CVR and the pilot and copilot audio panels on the accident helicopter was performed

at an FAA-certified repair station and was approved by the FAA on August 2, 2001. FAA

Form 337 also stated, ìan operational test of the CVR system was complied with.î

1.11.2 Flight Data Recorder

The accident helicopter was not equipped with a flight data recorder (FDR)

because, in August 2003, the S-76A became permanently exempt from Federal

regulations requiring the helicopter to be so equipped. Before the permanent exemption

was granted, Era Aviation had petitioned the FAA for an exemption from

14 CFR 135.152, ìFlight Recorders,î paragraph (a), to permit the company to operate two

of its newly acquired S-76A helicoptersóN575EH and N579EH (the accident

helicopter)óunder Part 135 without an FDR installed.48 Section 135.152(a), stated the

following at the time of the petition: 

No person may operate under this part a multi-engine, turbine-engine powered

airplane or rotorcraft having a passenger seating configuration, excluding any

required crewmember seat, of 10 to 19 seats, that was either brought onto the U.S.

register after, or was registered outside the United States and added to the

operatorís U.S. operations specifications after October 11, 1991, unless it is

equipped with one or more approved flight recorders that use a digital method of

recording and storing data and a method of readily retrieving that data from the

storage medium. 

In its June 11, 2001, letter, Era Aviation stated that operations without FDRs ìdo

not degrade safety.î The letter also stated that the Safety Boardís accident data for

rotorcraft operated under Part 135 with seating of 10 to 19 passengers do not indicate ìthat

the cause of accidents is in question or that the investigative process would have been

improved by the requirement for a DFDR [digital flight data recorder].î 

In an August 17, 2001, letter to Era Aviation, the FAA stated that it had previously

issued grants of exemption to petitioners with circumstances similar to those presented in

Eraís petition. The letter referred to Grant of Exemption No. 6785, dated June 12, 1998, in

which the FAA (specifically, the Director, Flight Standards Service) stated that the

petitioners had demonstrated ìvalid reasonsî for exempting several helicopter models,

48 In its letter, Era Aviation stated that it currently operated 37 other helicopters (with seating for 10 to

19 passengers) without FDRs installed.
Factual Information 18 Aircraft Accident Report

including the S-76A, from the FDR requirements,49 but the letter did not explain what

these reasons were. The letter also stated that the FAA had found that ìexempting certain

helicopters from the FDR requirements would be in the public interest and would not

adversely affect safety.î The letter further stated that Era Aviationís reasons for requesting

an exemption did not materially differ from those presented by the petitioner in Grant of

Exemption No. 6785. As a result, the FAA granted Era Aviation an exemption from

14 CFR 135.152(a) for N575EH and N579EH (Grant of Exemption No. 7605), which

allowed the company to continue to operate the helicopters without an FDR installed. The

FAAís letter stated that the exemption would terminate on January 31, 2004, unless it was

superseded or rescinded sooner. 

On August 18, 2003, the S-76A helicopter became permanently exempt from the

requirements of 14 CFR 135.152. Title 14 CFR 135.152(k) stated the following: 

For aircraft manufactured before August 18, 1997, the following aircraft types

need not comply with this section: Bell 212, Bell 214ST, Bell 412, Bell 412SP,

Boeing Chinook (BV-234), Boeing/Kawasaki Vertol 107 (BV/KV-107-II),

deHavilland DHC-6, Eurocopter Puma 330J, Sikorsky 58, Sikorsky 61N,

Sikorsky 76A.[50]

The final rule, which was issued on July 18, 2003 (and became effective 1 month

later), focused primarily on 14 CFR Part 121 parameter accuracy issues with large

transport-category Boeing and Airbus airplanes. The Safety Board commented on those

issues before the issuance of the final rule. The FAA did not notify the Board of its intent

to include the rotorcraft exemptions as part of the final rule and did not provide a comment

period for the final rule.51 Thus, the Board did not have the opportunity to formally state

its position on the rotorcraft exemptions before the issuance of the final rule.

The Era Aviation S-76A accident highlighted the problems associated with

rotorcraft exemptions from FDR requirements. As a result, on March 7, 2006, the Safety

Board issued Safety Recommendation A-06-18, which asked the FAA to remove the

current rotorcraft exemptions to 14 CFR 135.152(a). This recommendation is further

discussed in section 1.18.6.2.

49 The FAA stated the following in Grant of Exception No. 6785: ìfollowing the August 18, 1997,

effective date of Amendment No. 135-69, ëRevisions to Digital Flight Data Recorder Rules; Final Ruleí

(62 FR 38362, July 17, 1997), the FAA received requests from several helicopter operators for exemption

from the new DFDR requirements. The FAA found that the petitioners demonstrated valid reasons for

exempting the following helicopters from the DFDR requirements: Bell 212, Bell 214ST, Bell 412,

Bell 412SP, Sikorsky 61N, and Sikorsky 76A. Because the material presented by the petitioners concerning

those helicopters supported the FAAís finding of an exception to the rule, the exemptions were issued until

ß135.152(k) could be changed to include the affected helicopters as exceptions to the DFDR requirements.î

50 After the accident, Sikorsky began voluntarily equipping all of its new commercial aircraft, including

the S-76, with FDRs. 

51 Title 14 CFR 11.29 states that the FAA may issue a direct final rule without first issuing a notice of

proposed rulemaking (NPRM) if (1) an NPRM is ìimpracticable, unnecessary, or contrary to the public

interestî or (2) the agency does not expect any adverse comments to the changed rule.
Factual Information 19 Aircraft Accident Report

1.12 Wreckage and Impact Information

The helicopter wreckage was found on March 25, 2004. The wreckage was

recovered from the sea floor (a depth of about 186 feet) at a location about 70 nm

south-southeast of GLS in U.S. Gulf Coast VFR Aeronautical Chart reference area High

Island A-508.

The helicopter fuselage showed severe accordion-type crushing. The fuselage was

fragmented with pieces of structure attached to helicopter components. About 95 percent

of the structure was recovered. The structure showed no evidence of bird strikes, fatigue

fractures, or other anomalies. The nose cone had separated from the fuselage and showed

minor damage. The lower fuselage showed upward compression fractures. The tailboom

(the structure that connects the helicopterís fuselage to its tail rotor) had separated from

the helicopter fuselage. Inward crushing was found on the lower part of the structure that

attached the fuselage and tailboom, and tearing was found on the upper part of the

attachment structure. The bottom of the tailboom was undamaged.

 The front instrument panel was intact, and most instruments remained in their

respective mounting areas. The EFIS displays were shattered. No useful instrument data

were available.

Continuity of the cyclic, collective, and tail rotor pedal control systems could not

be established because of the breaks in the systems. All of the breaks were examined, and

no evidence of malfunction or failure was found. 

1.12.1 Main Rotor and Tail Rotor Systems

The main rotor drive shaft remained attached to the main transmission gearbox and

main rotor head. Two of the five sections of the tail rotor drive shaft were fractured, and

the other three sections of the tail rotor drive shaft were attached to the tail cone structure. 

All four main rotor blades were found fractured and with their blade roots still

attached to the main rotor hub. All blade fracture surfaces were consistent with static

bending overload and showed no evidence of fatigue. The rotor tips had separated from

the blades but were recovered in the main debris field.

Two of the tail rotor blades separated from the tail rotor just outboard of the rotor

cuff.52 The third tail rotor blade remained intact on the spar but had a flatwise spar fracture

near the root. The fourth tail rotor blade had fractured, and the outboard portion of the

blade was not recovered.53

52 The rotor cuff is located at the root end of the blade spar and attaches the blade to the rotor head.

53 Because a tail rotor blade is much smaller and flatter than a main rotor blade, the underwater

recovery of a tail rotor blade can be more difficult than that for a main rotor blade.
Factual Information 20 Aircraft Accident Report

The main, intermediate, and tail rotor gearboxes were examined at Sikorskyís facility.

The gearboxes showed no evidence of malfunction or failure, and none of the components

showed evidence of heat distress, warping, discoloration, or other signs of stress.

1.12.2 Powerplants

The left and right engines were found attached to the helicopter structure that

surrounds the engine compartment. The engines were found in their normal operating

position but had separated from their engine mounting points. The engines showed no

evidence of fire damage. 

The left and right engines were examined at the Turbomeca facility in Grand

Prairie, Texas. The examination revealed torsion fractures to both drive shafts.54 Evidence

(turbine blades on the left engine that had completely shed from the disk) showed that the

right engine had sensed an overspeed condition and activated its overspeed protection,

which included shutting down the fuel to the right engine and removing all overspeed

protection for the left engine. According to Turbomeca, during an accident sequence in

which both engines become decoupled from the transmission, one engine will overspeed,

and the other engine will not overspeed. 

Examination of the overspeed protection boxes found that both boxes had minor

external damage. One of the boxes (referred to as box A) was inscribed with the number 2,

but the wiring bundle connected to the box was labeled with the number 1. The other box

(referred to as box B) had no inscribed number to indicate its position, and no wiring

bundle was connected to the box. The boxesí electrical connecting pins were tested for

continuity, and the pins indicated that both boxes were not in an overspeed condition.

The overspeed protection boxes were disassembled and examined at Turbomecaís

facility in Tarnos, France. The internal examination of both boxes found no evidence of

soot, arcing, or overheating but found damage that appeared to be the result of seawater

immersion. A pin continuity test of box A showed that it was not in the overspeed position

but that its relay was found in the overspeed position. A pin continuity test of box B

showed that it was not in the overspeed position and that its relay also was not in the

overspeed position. 

1.12.3 Landing Gear

The main landing gear was found intact but heavily damaged. The main landing

gear doors were pushed upward and showed fractures that were consistent with the doors

being closed at impact. The main landing gear floats were folded inside the wheel wells,

and the floats were ripped. The main landing gear wheels, tires, and brakes were intact.

The nose landing gear was attached to its respective mounting area but had severe

structural deformation throughout the assembly. The nose gear support structure was in

the up position. The landing gear control valve was intact and in the up position.

54 The drive shafts transmit power from the engines to the main rotor blades.
Factual Information 21 Aircraft Accident Report

The electrical wiring for the landing gear warning system was examined for proper

routing, component placement, and evidence of anomalies. The wiring matched the

manufacturerís schematic drawing, which showed that the landing gear warning system

was configured to activate red ìLDG GEAR UPî lights under the glareshield panel and an

aural warning (a gear warning horn) over the pilotsí headsets when (1) the helicopterís

height above the ground, as measured by the radar altimeter, decreased below a pilot-set

decision height55 with the gear up or (2) the helicopterís airspeed was at or below 60 knots

indicated airspeed with the gear up.

The landing gear warning relay was found with damage that appeared to be the

result of seawater immersion. The relay was not functional and thus could not be tested

after the accident. A postaccident test flight aboard an Era Aviation S-76A helicopter

showed that its landing gear warning system (which was similar to that installed on the

accident helicopter) worked as indicated on the manufacturerís wiring diagram.

Specifically, the aural tone sounded until one of the LDG GEAR UP warning lights was

pressed, and the lights remained illuminated until the landing gear was lowered.56 The test

flight also demonstrated that the landing gear warning systemís lights were among the

brightest, and the aural warning was among the loudest, in the cockpit.

The landing gear warning lights were examined at the Safety Boardís

metallurgical laboratory in Washington, D.C. The light bulb filaments showed no

evidence of stretching.57

1.13 Medical and Pathological Information

Remains of both pilots and all eight passengers were recovered. Autopsies were

performed on both pilots, and no drugs of abuse were detected in either pilot.

1.14 Fire

The helicopter wreckage showed no evidence of an in-flight or a postcrash fire.

1.15 Survival Aspects

According to the County of Galveston Medical Examinerís Office, the cause of

death for the flight crew and passengers was multiple blunt force trauma injuries.

55 Because it is possible for the pilots to select different decision heights, the landing gear warning

system will activate at the higher of the two decision heights.

56 The aural tone and the warning lights could also be cleared if the helicopterís airspeed increased

above 60 knots and the helicopterís altitude increased above the higher pilot-selected decision height.

57 Stretching is the elongation of individual coils in light bulb filaments when the filaments are hot and

subjected to impact forces.
Factual Information 22 Aircraft Accident Report

1.16 Tests and Research

1.16.1 Cockpit Voice Recorder Study

The Safety Board conducted a CVR study to detect any aircraft system noise on

the recording, including the noise produced by the helicopterís rotor, engine, and

transmission. Numerous signals were evident on the CAM, but the following five signals

were prominent: tail rotor, bull gear mesh (in the main rotor transmission), piston passing

frequency of the hydraulic pump, bevel gear mesh (in the main rotor transmission), and

input helical mesh (in the main rotor transmission). These five signals remained constant

in frequency throughout the recording, which indicated that the system producing the

noise remained at a constant speed throughout the recording. The amplitudes of the bull

gear mesh and the bevel gear mesh changed toward the end of the recording, which

indicated a change in the signal strength.58

The signals that were evident in the recording indicated that, at the time of the

accident, the main rotor and the tail rotor were operating at a constant rotor speed. According

to Sikorsky Aircraft, the simultaneous changes in signal strength of the bull and bevel gear

meshes (at 1918:15) indicated that an increase in torque was applied to the transmission.

The Safety Boardís CVR study was also conducted to evaluate the background

noise recorded on the CAM channel. Generally, the noise of air flowing over the fuselage

directly influences the loudness (amplitude) of the broadband background noise of a CAM

recording. About 1918:25, the overall background noise level recorded on the CAM

decreased.59 The decrease in the background noise level continued until the end of the

CVR recording at 1918:34.

1.16.2 Actuator Testing

The Safety Board identified airworthiness concerns about S-76 actuators during

the investigation of the August 2005 accident involving an S-76C that crashed into the

Baltic Sea shortly after takeoff from Tallin, Estonia.60 As a result, the Safety Board

examined the three main rotor actuators installed on the Era Aviation S-76A accident

helicopter at HR Textron (the actuator manufacturer), Santa Clarita, California. The

examination showed that most of the actuator seals were intact with no damage61 and that

58 Specifically, the signal for the bull gear mesh began to decrease in strength until the signal

disappeared into the background noise at 1917:28. The signal reappeared at 1917:43 and increased in

strength at 1918:15. The signal for the bevel gear mesh decreased in strength beginning at 1918:15.

59 It was not possible for the Safety Board to correlate the noise level to a specific airspeed because the

accident CVR recording levels could not be calibrated to an external source.

60 In accordance with the provisions of Annex 13 to the International Convention on Civil Aviation, the

Safety Board has been assisting the Aircraft Accident Investigation Commission of Estonia with this

accident investigation. For more information, see DCA05RA089 and Safety Recommendations A-05-33

through -35 at the Safety Boardís Web site at <http://www.ntsb.gov>.

61 Only the forward actuatorís balance tube seals were worn, and one of the actuatorís seal caps had

fractured.
Factual Information 23 Aircraft Accident Report

the control valves moved freely with no blockages or restrictions. The piston headís

plasma coating was not flaked. Because of the condition of the actuators, they could not be

functionally tested.

1.17 Organizational and Management Information

1.17.1 Era Aviation

Era Aviation, LLC, is headquartered in Anchorage, Alaska.62 Era Aviation began

operations in the Gulf of Mexico in 1979. The accident helicopter was based at GLS, and

its operations and maintenance were managed by the companyís Gulf Coast headquarters

at LCH. At the time of the accident, Era Aviation had 7 S-76A helicopters in its Gulf of

Mexico fleet63 (including the accident helicopter) and employed 87 pilots who flew in the

Gulf of Mexico (including the accident flight crew).

1.17.1.1 S-76A Configurations

At the time of the accident, four of the seven S-76A helicopters in Era Aviationís

Gulf of Mexico fleet, including the accident helicopter, were digital and were configured

with an EFIS and a DDAFCS (as described in section 1.6.3).64 These helicopters provided

pilots with landing gear warnings when the helicoptersí airspeed was at or below 60 knots

or when the helicopter was at or below the decision height with the gear retracted.65 The

other three S-76A helicopters in Era Aviationís Gulf of Mexico fleet were analog and were

equipped with a Phase II automatic flight control system that was installed by the

manufacturer.66 These helicopters provided pilots with landing gear warnings only when

the helicoptersí airspeed was at or below 60 knots with the gear retracted.67

62 At the time of the accident, Era Aviation, Inc., was a subsidiary of Rowan Companies, Inc., of

Houston. In January 2005, Era Aviation, LLC, became a subsidiary of SEACOR Holdings, Inc., of Houston.

63 Other helicopters in the companyís Gulf of Mexico fleet at the time of the accident included the

Sikorsky 61, Bell 212/412, Boelkow 105, Agusta 109, and Eurocopter 332L (Super Puma) and 350.

64 The accident captain completed EFIS-DDAFCS training in December 2001. The accident copilot

received EFIS-DDFACS training as part of initial training. For information about Era Aviationís training

program, see section 1.17.1.2.

65 As stated in section 1.12.3, the accident helicopterís landing gear warning lights were located under

the glareshield panel. The landing gear warning lights for the other three digital helicopters were located at

the bottom of the front instrument panel near the center pedestal. 

66 The Phase II automatic flight control system maintains selected attitudes and provides stabilization in 

the pitch, roll, and yaw axes. The Phase II system consists of two separate but identical systems that

introduce signals into the flight control system through the pitch, roll, and yaw operational channels to

correct any difference between a preset flight attitude and the actual flight attitude. The helicopters equipped

with a Phase II automatic flight control system do not have EFIS or flight directors.

67 The landing gear warning lights on two of the analog helicopters were also located under the 

glareshield panel. The warning lights on the other analog helicopter were located above each pilotís airspeed

indicator. 
Factual Information 24 Aircraft Accident Report

1.17.1.2 Ground and Flight Training

Era Aviationís S-76A initial ground training consisted of 40 hours of classroom

training during a 5-day period. During a postaccident interview, Era Aviationís director of

training at LCH stated that the primary instructors for initial ground training were check

airmen, who followed the FAA-approved curriculum and prepared a syllabus, lesson plans,

pilot training manuals, PowerPoint presentations, and other needed materials. The director of

training stated that he was responsible for overseeing the format of the training information.

The initial ground training syllabus listed 14 lessons that were presented during the

course ìto provide the ground training necessary to familiarize and train each

crewmember in the operation of the Sikorsky S76 helicopter and to assure that the

crewmember can completely and safely perform his/her assigned duties.î The 14 lessons

included 4 hours of instruction for the flight control and automatic flight control systems;

2 hours of instruction for the avionics system; 3 hours of instruction for familiarization

with aircraft flight manuals; and 4 hours of instruction on the caution warning, electrical

power, and lighting systems. A quiz was given at the end of each lesson, and an

examination was given at the end of the course; each pilot had to receive a minimum score

of 80 percent on all of the quizzes and the examination.

Initial ground training was delivered in lecture format using information from Era

Aviation training manuals and PowerPoint presentations. The Era Aviation S-76 Pilot

Training Manual included detailed descriptions of the analog and digital flight control

systems, and the Era Aviation S-76 Training Flight Manual included all operating

handbooks and required supplements. Pilots were provided with copies of the manuals

during the training. The PowerPoint presentations included schematics and photographs of

the various components of the analog and digital flight control systems. The training

included limited information on flight director and coupling status annunciations and

command cue presentations.

During initial ground training, pilots also received a copy of Era Aviationís

Operations Manual. This manual contained guidelines for Era Aviationís operations,

which were not specific to any aircraft type in the companyís fleet. Pilots receive revisions

to the manual as they are printed.

Part of initial ground training was dedicated to controlled flight into terrain (CFIT)68

and crew resource management (CRM). All Era Aviation pilots were required to watch a

30-minute videotape on CFIT prepared by Boeing. The videotape emphasized the importance

of communication and crosscheck procedures in preventing CFIT. The director of training at

LCH stated that, during the CFIT portion of his training, the accident captain spoke about his

flight experiences with the Coast Guard, discussed the risk factors associated with flying to an

offshore platform at night, and was ìthe most vocal and active participant in the class.î Also,

Era Aviation pilots were required to view a 45-minute PowerPoint presentation on

aeronautical decision-making. The presentation cautioned pilots about becoming overly

confident with increased experience and provided information about various helicopter

68 For more information about CFIT, see section 1.18.4.
Factual Information 25 Aircraft Accident Report

accidents. In addition, pilots watched three videotapes about pilot decision-making, one of

which discussed the human factor considerations present in aviation safety.

Initial flight training consisted of 10 hours of flight time. This flight time was

divided into six 90-minute periods and one 2-hour period during which pilots were given a

Part 135 flight check.69

Era Aviationís S-76A recurrent ground and instrument training was conducted at

its headquarters during a 6-day period (6 hours each day). The training was presented

along with recurrent ground and instrument training for the Sikorsky S-61 and the

Bell 412. Topics covered during the training for all three helicopter models included

aircraft flight manual and flight standards guide information, systems training (flight

control and hydraulic systems), navigation, meteorology, instrument flight rules (IFR)

procedures, maintenance, CFIT, CRM, situational awareness, and safety (accident and

incident review). Examinations were given for each training subject.

Era Aviation required its S-76A pilots to attend a minimum of 6 hours of recurrent

simulator flight training each year. This training was conducted during four 1.5-hour

sessions at FlightSafety International, West Palm Beach, Florida, in an S-76A simulator

equipped with an EFIS and a DDAFCS. The first session consisted of simulator

familiarization, including normal approaches to oil rigs, and selected malfunctions and

emergencies. The second session consisted of instrument procedures and weather

considerations. The third session consisted of a review of VFR and IFR procedures and

CRM procedures. Each of these sessions concluded with a debriefing. The fourth session

consisted of a Part 135 flight check and a question-and-answer period. An Era Aviation

captain stated that the simulator sessions included at least 2 hours of night flying under

IFR. He also stated that at least two offshore approaches to an oil rig were conducted

down to 200 feet with 0.6 mile visibility.

Era Aviationís simulator coordinator (who was also an S-76A check airman) stated

that, before the accident, coupling indications and related issues were not a focus of the

DDAFCS portion of ground or simulator flight training. He also stated that, after the accident,

Era Aviation focused the DDFACS portion of the training on improving a pilotís situational

awareness regarding the system and decreasing the possibility of confusion between pilots.

Era Aviationís check airmen provided annual flight checks to company PICs.

According to an Era Aviation vice president, the flight checks generally involved flights to

offshore platforms or ships or flights near LCH for checks of emergency procedures.

1.17.1.3 Visual Flight Rules Flight Plans

As stated in section 1.1, the accident helicopterís VFR flight plan was not filed

with the FAA. In a July 12, 2004, letter to the Safety Board, an Era Aviation vice president

69 These flight checks were conducted pursuant to 14 CFR 135.293, ìInitial and Recurrent Pilot Testing

Requirements,î 14 CFR 135.297, ìPilot in Command: Instrument Proficiency Check Requirements,î and/or

14 CFR 135.299, ìPilot in Command: Line Checks: Routes and Airports.î
Factual Information 26 Aircraft Accident Report

stated that about 600 helicopters fly in the Gulf of Mexico, many of which fly numerous

flight segments each day, and that it would therefore be ìimpracticalî and

ìoverwhelmingî to file every VFR flight plan with the FAA. This vice president stated

that the company adhered to 14 CFR 135.79(a), ìFlight Locating Requirements,î for its

VFR flight plans. Title 14 CFR 135.79(a) states the following:

Each certificate holder must have procedures established for locating each flight,

for which an FAA flight plan is not filed, that ñ (1) provide the certificated holder

with at least the information required to be included in a VFR flight plan; (2)

provide for timely notification of an FAA facility or rescue facility, if an aircraft is

overdue or missing; [and] (3) provide the certificate holder with the location, date,

and estimated time for reestablishing radio or telephone communications, if the

flight will operate in an area where communications cannot be maintained.

1.17.2 Federal Aviation Administration

The principal operations inspector (POI), assistant POI, principal maintenance

inspector, and principal avionics inspector at the FAAís Anchorage office provided

oversight for Era Aviation. Flight checks for check airmen at Era Aviationís Gulf Coast

headquarters were conducted by the assistant POI or by designated examiners from the

FAAís Baton Rouge, Louisiana, office. Era Aviationís director of operations stated that

the flight checks were performed on shore and near LCH.

1.18 Additional Information

1.18.1 Flight Simulations

Safety Board staff members evaluated the flight characteristics of the accident

helicopter using a full-motion, FAA-certified flight check S-76A simulator at

FlightSafety. The simulatorís cockpit configuration replicated, as much as possible, that of

the accident helicopter (as determined by preaccident photographs of the helicopterís front

instrument panel).70 The simulatorís mechanical radar altimeter indicator was not used

because the accident helicopter was not equipped with a mechanical radar altimeter

indicator. Also, the simulatorís landing gear warning system triggered only when airspeed

decreased below 60 knots with the gear up.71

The Safety Board examined numerous possible scenarios that could lead to an

inadvertent descent to understand the systems and annunciations that were available to the

70 Although the simulatorís cockpit configuration did not exactly replicate that of the accident

helicopter, the simulatorís flying characteristics closely resembled those of the accident helicopter. 

71 As stated in section 1.17.1.2, Era Aviation S-76A pilots received recurrent training using this S-76A

simulator. Even though this simulator had a landing gear warning system that triggered only when the

helicopterís airspeed was 60 knots or below with the gear retracted, the predominant method of flight

training was actual flights aboard company helicopters, during which the pilots would have been trained on

helicopters with both landing gear warning system configurations. 
Factual Information 27 Aircraft Accident Report

flight crew. As shown in figure 5, the following indications of descent were seen on the

pilotsí ADIs during the scenarios:

ï The radar altitude appeared in blue at the bottom right of the ADIs followed by

an ìRAî indication in white.

ï The decision height was displayed in blue at the bottom left of the ADIs

followed by a DH indication in white. A white square box appeared above the

radar altitude (at the bottom right of the ADIs) when the helicopter was

100 feet above the decision height (based on the radar altimeter). When the

decision height was reached, an amber DH indication appeared inside the box

and remained there as the helicopter continued to descend.

ï A yellow rising runway symbol appeared at the bottom center of the ADIs at

180 feet (based on the radar altimeter). As the helicopterís altitude decreased,

this symbol ascended until it met the aircraft symbol at 0 feet.

Other indications of descent seen on the pilotsí instrumentation during the

scenarios were the following:

ï The barometric altimeters showed decreasing altitude by the counterclockwise

rotation of the needle.72

ï The vertical speed indicators (VSI) showed a rate of descent of 250 to 300 fpm,

which placed the needle below the centerline position.73

Figure 5. Indications of Descent on the Attitude Direction Indicator

72 The barometric altimeters are located directly to the right of the ADIs (see figure 1).

73 The VSIs are located directly below the barometric altimeters and directly to the right of the HSIs (see

figure 1). The VSI tick marks between 0 and 1,000 feet represent increments of 100 fpm, and the tick marks

between 1,000 and 3,000 feet represent increments of 500 fpm.
Factual Information 28 Aircraft Accident Report

In addition, for one scenario, an altitude of 900 feet was selected on the air data

command display (the AL-300).74 At an altitude of 600 feet (300 feet below the

preselected altitude), an amber altitude alert light at the top left of the barometric

altimeters illuminated,75 and a 1-second aural tone sounded over the pilotsí headsets. The

light remained illuminated for the rest of this simulation.76 Figure 6 shows the amber

altitude alert light on one of the simulatorís barometric altimeters.

Of the numerous possible scenarios that could lead to an inadvertent descent, the

Safety Board focused on the four scenarios that were deemed to be the most likely to have

occurred during the accident flight if the flight crew had engaged the DDAFCS. For

detailed information about each of the four scenarios, see appendix C.

74 The altitude preselect value is entered by turning the ìsetî knob until the AL-300 shows the desired

value. The selected altitude is shown on the display until the altitude is captured. The AL-300 also displays

commanded vertical speed, airspeed, and radar altitude depending on the mode (VS, IAS, or ALT) selected

on the flight director mode selector. The parameters are displayed during the time that each is being adjusted

by the pilot and for 7 seconds after the adjustment.

75 When the helicopter is descending, the altitude alert light illuminates at 1,000 feet above the

preselected altitude. The light does not illuminate from about 300 feet above the preselected altitude to about

300 feet below the preselected altitude. Afterward, the light illuminates again until the helicopter descends

beyond 1,000 feet below the preselected altitude, at which point the light is no longer illuminated.

76 The accident helicopter was equipped with two barometric altimeters, but only the captainís

barometric altimeter had an altitude alert light at the top left of the instrument.

Figure 6. Altitude Alert Light
Factual Information 29 Aircraft Accident Report

1.18.2 Gulf of Mexico Helicopter Operations

 According to the latest statistics from the Helicopter Safety Advisory Conference

(HSAC),77 561 oil industry helicopters (single engine, light twin, medium twin, and heavy

twin) operated in the Gulf of Mexico during 2004, transporting more than 2.3 million

passengers aboard 1.3 million flights. Table 2 shows the 2004 Gulf of Mexico oil industry

helicopter accident rate and fatal accident rate per 100,000 flight hours compared with the

same information for all U.S. air carrier operations under on-demand Part 135 (charter and

air taxi).78 (Even though the FAAís General Aviation and Air Taxi Survey79 distinguishes

between fixed-wing airplane and rotorcraft flight hours, the survey estimates of flight

hours for rotorcraft do not reliably compare to HSACís flight hour estimates for offshore

helicopter operations. Thus, only the overall rates for on-demand Part 135 accidents are

reported.) Table 3 shows this information for the 5-year period between 2000 and 2004.

Appendix D provides a list of Gulf of Mexico helicopter accidents from March 2000 to

February 2006. 

Table 2. 2004 Accident Rates for Gulf of Mexico Helicopter Operations and On-Demand 

Part 135 Air Carrier Operations

a

 The Gulf of Mexico estimate of flight hours was obtained from the HSACís Gulf of Mexico Offshore Helicopter Operations 

and Safety Review.

b

 Accident rate calculations for on-demand Part 135 operations (fixed-wing airplanes and rotorcraft) were estimated using 

data from the FAAís General Aviation and Air Taxi Survey.

77 According to its Web site, the HSAC was formed in January 1978 to promote improved

communication and safe practices within the Gulf of Mexico offshore community. The HSAC consists of

representatives from major petroleum companies; drilling companies; helicopter operators; oil industry

service companies; helicopter manufacturers; and U.S. Federal agencies, including the FAA, the Army, the

Air Force, the Navy, the Coast Guard, the Department of the Interior, and the Customs Service. Since 1998,

HSAC has annually surveyed 22 helicopter operators that provide on-demand Part 135 helicopter services in

the Gulf of Mexico. The survey compiles operational and flight activity data, including fleet size and

characteristics; number of passengers, flights, and flight hours; and accident statistics. These data are

published annually in HSACís Gulf of Mexico Offshore Helicopter Operations and Safety Review.

78 On-demand Part 135 air carrier operations include rotorcraft and fixed-wing airplanes. 

79 Data for the General Aviation and Air Taxi Survey are compiled annually by the FAA based on

voluntary data from Part 135 operators.

Operation

Number of 

flight hours

Accident rate per 

100,000 flight hours

Fatal accident rate per 

100,000 flight hours

Gulf of Mexico 

helicopters

 362,000a 2.77 1.11

On-demand Part 135 

aircraftb 3,238,000 2.10 0.74
Factual Information 30 Aircraft Accident Report

Table 3. Accident Rates for Gulf of Mexico Helicopter Operations and On-Demand 

Part 135 Aircraft Operations for 2000 Through 2004

a

 The Gulf of Mexico accident rates were calculated using estimates of flight hours from the HSACís Gulf of Mexico 

Offshore Helicopter Operations and Safety Review.

b

 Accident rate calculations for on-demand Part 135 operations (fixed-wing airplanes and rotorcraft) were estimated using 

data from the FAAís General Aviation and Air Taxi Survey.

Safety Board staff members visited two Gulf of Mexico helicopter operatorsóPHI

of Lafayette, Louisiana, and Air Logistics of New Iberia, Louisianaóto compare and

contrast their operations with Era Aviationís operations. Although each companyís fleet

consists of similar helicopter models, PHI and Air Logistics operate a larger fleet of

helicopters than Era Aviation (more than 220 at PHI and more than 170 at Air Logistics

compared with about 100 helicopters at Era Aviation). Also, PHI and Air Logistics

operate both domestically and internationally, whereas Era Aviation operates domestically

in Alaska, the West Coast, and the Gulf Coast. All three operatorsí helicopters fly at low

altitudes while en route.

All three operators have dispatchers at their Gulf Coast headquarters (Era Aviation

has 3 dispatchers, PHI has between 8 and 12 dispatchers, and Air Logistics has

2 dispatchers), but only Air Logistics has additional dispatchers at all of the locations

where the companyís helicopters are operating (one dispatcher per location). All three

operators currently use flight-tracking software and hardware purchased from commercial

vendors.80 The software displays chevrons to indicate aircraft in flight and their direction

along with weather overlays, and the hardware allows company pilots and dispatchers to

relay text messages to each other. As with Era Aviation pilots, Air Logistics pilots call a

company dispatcher to provide a position report every 15 minutes and to close out the

flight plan; PHI pilots do not call a company dispatcher with position reports unless the

Year Gulf of Mexico helicoptersa On-demand Part 135 aircraftb

Accident rate per 

100,000 flight 

hours

Fatal accident 

rate per 100,000 

flight hours

Accident rate per 

100,000 flight 

hours

Fatal accident 

rate per 100,000 

flight hours

2000 2.04 0.68 2.04 0.56

2001 1.77 0.22 2.40 0.60

2002 1.49 0.25 2.06 0.62

2003 3.93 1.84 2.56 0.61

2004 2.77 1.11 2.10 0.74

Average 2.40 0.82 2.22 0.62

80 At the time of the accident, Era Aviation did not have this flight-tracking capability. As stated in

section 1.1, dispatchers at Era Aviationís Gulf Coast headquarters entered information about company

flights in a computerized log after each radio transmission. This information was displayed on a screen

showing each helicopterís tail number in black, the departure location in yellow, the destination location in

red, and the helicopterís flight plan between the two locations.
Factual Information 31 Aircraft Accident Report

customer requests so, but the pilots do call the dispatcher to close out the flight plan. All

three operators stated that they did not receive weather information or flight-tracking

services from the FAA.

All three companies conduct training at their headquarters and at FlightSafety. Era

Aviation does not have simulators on site, but PHI and Air Logistics have two fixed-base

simulators on site that have similar instrumentation and performance capabilities as most

of the aircraft in their fleets. All three companies conduct daily maintenance at their bases

of operation and heavy maintenance at their headquarters.

1.18.3 Automatic Dependent SurveillanceñBroadcast 

Technology

In 1998, the FAA developed an initiative under the Safe Flight 21 program for the

Gulf of Mexico. The Safe Flight 21 program focused on providing pilots with radar-like

information (navigation, air traffic, terrain, and weather) in the cockpit and enabling air

traffic controllers and operators to provide surveillance of low-flying aircraft in those

areas with limited or no radar coverage. 

The Safe Flight 21 Gulf of Mexico initiative included plans to provide a groundand satellite-based infrastructure called automatic dependent surveillanceñbroadcast

(ADS-B), which relies on position information that is transmitted by individual aircraft

based on global positioning system (GPS) technology. Each ADS-B-equipped aircraft has

the capability to broadcast its position using a digital data link that provides information

on the aircraftís airspeed and altitude and an indication of whether the aircraft is turning,

climbing, or descending. This information can be directly transmitted from one aircraft to

another, or the information can be transmitted to an ADS-B ground station,81 combined

with other aircraft data, and transmitted back to any aircraft within range of an ADS-B

ground station. The information can also be transmitted by landlines or other means to air

traffic controllers in distant locations. In addition, ADS-B can be used as the enabling

technology that will allow weather, traffic, conflict alert, and other information available

to personnel on the ground to be provided to pilots.

The Safe Flight 21 Gulf of Mexico initiative also included a network of ADS-B

ground stations that were tested on offshore platforms. These ground stations transmitted

and received high accuracy, radar-like flight-tracking information for ADS-B-equipped

aircraft. In addition, data received by these ground stations were transmitted and processed

at the Houston Air Route Traffic Control Center and the Lafayette Terminal Radar

Approach Control so that controllers at these locations had real-time positional data on test

ADS-B-equipped aircraft operating in the Gulf of Mexico. This test was conducted by the

National Aeronautics and Space Administration between 2001 and 2004 with the use of

81 A ground station is a site equipped with a device that transmits and receives signals.
Factual Information 32 Aircraft Accident Report

several ADS-B-equipped aircraft,82 and the test data were provided to the FAA. The ADS-B

infrastructure in the Gulf of Mexico was removed in 2005 because of the lack of funding.

Another initiative under the Safe Flight 21 program was the Capstone program

in Alaska, which was developed to improve aviation safety in areas of Alaska with a

high accident rate. The FAA planned to implement the Capstone program in three

phases (based on geographic area). According to the FAA, at the beginning of March

2006, 341 aircraft in Alaska had been equipped with ADS-B technology during the first

two phases of the program. The FAA also indicated that the final Capstone phase was

currently under development with funding for site surveys but not construction.

Information from the FAAís November 2005 Flight Technologies and Procedures

New Technologies Workshop showed that the FAA did not plan to implement the Safe

Flight 21 Gulf of Mexico initiative until fiscal year 2013. In January 2006, the FAA

announced that the Safe Flight 21 program was being transitioned to the National ADS-B

Program. Although the content of both programs was basically the same, the

implementation dates for the National ADS-B Program were moved forward. Specifically,

the FAA proposed fiscal year 2007 to begin implementation of the program and fiscal

year 2010 to complete the first segment of ADS-B infrastructure deployment. On

March 1, 2006, the FAA informed the Safety Board verbally that the Gulf of Mexico

would be among those areas in the first segment of ADS-B deployment. The FAA also

informed the Board that it planned to seek budget approval for the National ADS-B

Program in June 2006.

1.18.4 Controlled Flight Into Terrain 

CFIT occurs when a controlled, serviceable aircraft is flown into terrain, obstacles,

or water with no prior awareness by the flight crew of the impending collision.83 Between

1987 and 2004, 56 (25 percent) of the 226 worldwide fatal accidents involving large

commercial jet aircraft were classified as CFIT, resulting in 3,631 fatalities.84 Most CFIT

accidents occurred with poor visibility conditions and during the approach and landing

phases of flight.85 Although the number of CFIT accidents has markedly declined in recent

years for U.S. transport-category airplanes,86 CFIT remains a major aviation problem in

foreign countries and for general aviation aircraft and helicopters.

A Flight Safety Foundation study indicated that about 75 percent of all CFIT

accidents in commercial aircraft occurred in those that were not equipped with a

82 These aircraft were an FAA Boeing 727, an FAA Convair, a Piper Aztec from the Department of

Transportationís Volpe National Transportation Systems Center, and a PHI helicopter.

83 E.L. Weiner, ìControlled Flight Into Terrain: System Induced Accidents,î Human Factors Journal

Vol. 19 (1977).

84 Boeing Commercial Airplane Group, ìStatistical Summary of Commercial Jet Aircraft Accidents,

Worldwide Operations 1959-2004,î (Seattle, WA: May 2005).

85 R. Khatwa and R. Helmreich, ìAnalysis of Critical Factors During Approach and Landing in Accidents

and Normal Flights,î Flight Safety Digest (November 1998ñFebruary 1999): Flight Safety Foundation.

86 The Safety Board issued numerous safety recommendations to prevent CFIT.
Factual Information 33 Aircraft Accident Report

traditional ground proximity warning system (GPWS).87 A traditional GPWS uses the

radar altimeter to calculate closure rate with terrain to predict a potential collision threat.

Although a traditional GPWS can help prevent CFIT, a traditional GPWS cannot provide

a timely warning to the flight crew if the terrain rises steeply. As a result, on October 16,

1996, the Safety Board issued Safety Recommendation A-96-101,88 which asked the FAA

to do the following:

Examine the effectiveness of the enhanced ground proximity warning equipment

and, if found effective, require all transport-category aircraft to be equipped with

enhanced ground proximity warning equipment that provides pilots with an early

warning of terrain.

Enhanced GPWS is also referred to as a terrain awareness and warning system

(TAWS). These systems have the ability to look ahead of an aircraft to determine the

terrain or other obstruction along the flightpath, thereby providing pilots with more time to

determine the necessary corrective actions than with a traditional GPWS.

When used for helicopter operations, TAWS can include a forward-looking terrain

awareness display, which provides aural alerts and visual indications of terrain and

obstacles. The aural alerts are ìcaution terrain,î ìwarning terrain,î ìcaution obstacle,î and

ìwarning obstacle.î The visual indications of terrain and obstacles can be displayed on

one or two screens on the front instrument panel or can be incorporated into EFIS

displays. In addition, TAWS for helicopters can include aural alert modes 1 through 6,

which are excessive descent rate, excessive terrain closure rate, descent after takeoff,

terrain clearance, deviation below glideslope, and autorotation and altitude,89 respectively.

The accident helicopter was not equipped with a TAWS and was not required by

Federal regulations to so be equipped.90 Specifically, a March 23, 2000, final rule issued

by the FAA required all U.S.-registered turbine-powered airplanes configured with six or

more passenger seats to be equipped with a TAWS by March 29, 2002 (new-production

airplanes), and March 29, 2005 (existing airplanes). As a result of the FAAís action,

Safety Recommendation A-96-101 was classified ìClosedóAcceptable Actionî on

February 15, 2001.

87 R. Khatwa and A.L.C. Roelen, ìAn Analysis of Controlled-Flight-Into-Terrain (CFIT) Accidents of

Commercial Operators, 1988 Through 1994,î Flight Safety Digest (AprilñMay 1996): Flight Safety

Foundation.

88 This recommendation was issued in response to the December 20, 1995, accident involving

American Airlines flight 965, which struck trees and crashed into a side of a mountain near Cali, Colombia,

during night VMC. The airplane was equipped with a traditional GPWS. About 12 seconds before impact,

the GPWS began issuing the aural warnings ìterrainî and ìpull up,î but these warnings were not provided in

time for the flight crew to avoid crashing into the mountainous terrain.

89 If a decision height is set, the mode 6 ìaltitude altitudeî aural alert would occur at that height unless

a higher priority alert, such as ìcaution terrainî or ìwarning terrainî takes precedent.

90 In May 2004, Sikorsky announced that it would voluntarily equip its new S-76 helicopters with

TAWS. Sikorsky subsequently announced that it would offer a TAWS/CVR/FDR retrofit program for all

S-76 helicopters built before 2005.
Factual Information 34 Aircraft Accident Report

As part of this investigation, the Safety Board requested that Honeywell (the

manufacturer of TAWS for helicopters) perform simulations of a 150- and 250-fpm

descent into water to determine what alerts could have been expected if a TAWS had been

installed aboard the accident helicopter.91 For a descent rate of 150 fpm, the simulation

showed that the ìcaution terrainî alert would have occurred 97 seconds before impact,

along with a water indication that changed from blue to yellow on the forward-looking

terrain awareness display.92 The simulation also showed that the ìwarning terrainî alert

would have occurred 84 seconds before impact, along with a water indication that changed

from yellow to red on the forward-looking terrain awareness display. For a descent rate of

250 fpm, the simulation showed that the caution terrain alert would have occurred 68

seconds before impact and that the warning terrain alert would have occurred 55 seconds

before impact (along with the water indication color changes on the forward-looking

terrain awareness display).

In January 2006, the Safety Board adopted a special investigation report on

emergency medical services (EMS) aircraft accidents.93 According to the report, 55 EMS

accidents occurred between January 2002 and January 2005; these accidents involved

41 helicopters and 14 airplanes and resulted in 55 fatalities and 18 serious injuries. The

Board found that TAWS might have helped pilots avoid terrain in 17 of the 55 accidents.

(Thirteen of these 17 accidents involved helicopters.) As a result, the Board issued Safety

Recommendation A-06-15, which asked the FAA to do the following: 

Require emergency medical services (EMS) operators to install terrain awareness

and warning systems on their aircraft and to provide adequate training to ensure

that flight crews are capable of using the system to safely conduct EMS

operations. 

1.18.5 Comparison of SPZ-7000 and SPZ-7600 Dual Digital 

Automatic Flight Control Systems

The SPZ-7000 DDAFCS, which was installed on the accident helicopter, is no

longer in production. Its successor is the SPZ-7600 DDAFCS, which was originally

designed for the S-76C.94 Although the SPZ-7000 and the SPZ-7600 are similar, there are

differences between the systems, including the display presentation of command cues for

an unselected axis and the indications for system coupling and decoupling.

91 Radar data showed that the helicopterís descent rate at an altitude of 1,100 feet was 250 fpm. The

Safety Board estimated that the helicopter impacted the water at a descent rate of 150 fpm. 

92 The color change would have occurred because the TAWS would have detected that the closure rate

to the water was a concern.

93 National Transportation Safety Board, Special Investigation Report on Emergency Medical Services

Operations, Aviation Special Investigation Report NTSB/SIR-06/01 (Washington, DC: NTSB, 2006).

94 The FAA issued a supplemental type certificate to allow the S-76A to be retrofitted with the

SPZ-7600.
Factual Information 35 Aircraft Accident Report

Both the SPZ-7000 and the SPZ-7600 have the capability to display pitch and roll

command cues in either a dual- or a single-cue format. With the dual-cue format, pitch

attitude is represented by a horizontal line, and roll attitude is represented by a vertical

line, as shown in figure 7. With the single-cue format, angular bars integrate pitch and roll

guidance, as shown in figure 8. When both pitch and roll commands are selected in either

mode, the guidance provided by the command cues is intuitive and well understood by

pilots who have been trained on either flight control system.

Figure 7. SPZ-7000 Dual-Cue Format

Figure 8. SPZ-7000 Single-Cue Format
Factual Information 36 Aircraft Accident Report

Also, both the SPZ-7000 and the SPZ-7600 have the capability for the pilot to

select a command cue for only one axis, either pitch or roll, at a time. The displayed cue

for the selected axis is functionally the same as when command cues for both axes are

selected. However, depending on the system and the command cue format, the command

cue for the unselected axis may or may not be displayed. In addition, no annunciation

appears on the ADIs regarding the source of guidance for the unselected command cue

presented in the SPZ-7000 dual- and single-cue formats and the SPZ-7600 single-cue

format.

Table 4 summarizes the command cues presented on the SPZ-7000 and SPZ-7600

DDAFCS and highlights the differences in attitude synchronization between the two

systems. These differences, which are not intuitive, are analyzed in section 2.3.2.

Table 4. Command Cues Presented on the SPZ-7000 and SPZ-7600 DDAFCS With 

Single-Axis Command Selections

In addition, the indications for coupling and decoupling are distinctly different

between the SPZ-7000 and SPZ-7600 DDAFCS. As stated in section 1.6.3, the SPZ-7000

does not annunciate the coupling status on the front instrument panel, and the SPZ-7000

DCPL warning indicator on the DAFCS caution panels illuminates only during abnormal

operations. For the SPZ-7600, the DCPL warning indicator on each DAFCS caution panel

illuminates during normal and abnormal operations whenever the autopilot and flight

director become decoupled for an activated mode. Once the DCPL warning indicators are

annunciated, annunciations can be cleared by either coupling the autopilot and flight

director or resetting the couple logic by disengaging and reengaging one or both of the

autopilots.

Finally, the SPZ-7600, as delivered from the manufacturer (Honeywell), is not

equipped with an aural alert to indicate system decoupling under normal operations.

Operators that use the SPZ-7600 can install an after-market product to provide this aural

Display format Axis selected

SPZ-7000 unselected 

axis

SPZ-7600 unselected 

axis

Dual cue Pitch only Roll indication is 

synchronized to the 

trimmed roll attitude.

Roll indication is not 

shown.

Roll only Pitch indication is 

synchronized to the 

trimmed pitch attitude.

Pitch indication is not 

shown.

Single cue Pitch only Roll indication is 

synchronized to the 

trimmed roll attitude.

Roll indication is 

centered.

Roll only Pitch indication is 

synchronized to the 

trimmed pitch attitude.

Pitch indication is 

centered at the horizon.
Factual Information 37 Aircraft Accident Report

alert as either a chime or a verbal annunciation (ìdecoupleî).95 One manufacturer

(Sikorsky) installs this aural alert (manufactured by Keystone Helicopters) on all of its

helicopters that are equipped with the SPZ-7600.

1.18.5.1 Federal Aviation Administration SPZ-7000 Evaluation

As a result of the Safety Boardís investigation of this accident, and to ensure the

safety of the S-76 fleet, the FAA evaluated the SPZ-7000 DDAFCS to determine whether

ìhazardously misleadingî flight director data were being presented on EFIS displays. The

evaluation was conducted during February 2005 in an S-76A simulator and helicopter that

were similarly configured to the accident helicopter. The FAA provided notes about its

evaluation to the Board. The notes indicated the following observations: 

There is no aural or visual annunciation of a pilot-induced decouple.

The only cues that the flight director is not coupled on the selected side are the

lack of FD mode selections and the disappearance of FD mode annunciations on

the corresponding EADI [electronic ADI].

With cross-needle FD cues selected on the EADI, single-axis FD modes (HDG

only, ALT only, etc.) caused both pitch and roll cue needles to be displayed. With

only HDG mode selected, the pitch cue bar apparently provides guidance only to

retain the aircraftís existing pitch attitude when HDG mode was selected. It did

not provide guidance to maintain a selected altitude. A vertical mode (ALT, VS,

ILS) must be selected for the pitch bar to provide vertical navigation steering

commands. This is apparently different from other S-76 DAFCS systems such as

the SPZ-7600, and from some Part 23 or Part 25 fixed-wing flight director

systems.

In general, the indications of either a pilot-induced or self-induced FD decouple

were not particularly compelling.

In its notes, the FAA recommended that the certification basis for the SPZ-7000

DDAFCS be reviewed to ensure that, at the time of certification, the system met all

requirements for coupled flight director disconnect annunciations. Also, the FAA

recommended that the presentation of single-cue flight director commands by the

SPZ-7000 be further examined in the context of certification requirements and continued

operational safety. 

In November 2005 correspondence, the FAA stated that it reviewed the

certification basis of the SPZ-7000 DDAFCS and determined that, at the time of

certification, the system did meet the requirements of 14 CFR 29.1335 and

14 CFR 29.1329. Also, the FAA stated that it found no evidence to indicate that the

SPZ-7000ís disconnect annunciations were inadequate or that the SPZ-7000 was a factor

in previous S-76 accidents.

95 This alert can be configured (according to customer preference) to provide an aural annunciation in

pilotsí headsets, the cabin, or both.
Factual Information 38 Aircraft Accident Report

1.18.6 Previous Flight Recorder Safety Recommendations

1.18.6.1 Safety Recommendation A-02-25

On August 29, 2002, the Safety Board issued Safety Recommendation A-02-25 as

a result of its long-standing concerns about the availability of CVR information after

reportable accidents or incidents. Safety Recommendation A-02-25 asked the FAA to do

the following:

Require that all operators of airplanes equipped with a cockpit voice recorder

(CVR) test the functionality of the CVR system prior to the first flight of each day,

as part of an approved aircraft checklist. This test must be conducted according to

procedures provided by the CVR manufacturer and shall include, at a minimum,

listening to the recorded signals on each channel to verify that the audio is being

recorded properly, is intelligible, and is free from electrical noise or other

interference.

On December 12, 2002, the FAA responded that current regulations

(14 CFR 23.1457 and 25.1457) require CVR equipment to have ìan aural or visual means

for preflight checking of the recorder for proper operation.î The FAA also stated that it

would survey current maintenance practices of air carrier and general aviation aircraft to

determine if corrections to the operatorsí maintenance programs were necessary to ensure

expected recorder reliability. On January 16, 2003, the Safety Board replied, stating its

concern that the FAAís maintenance survey would address only one part of the CVR

reliability problem. The Boardís safety recommendation letter stressed that it was the

flight crewís responsibility to check the CVR for proper operation each day before the first

flight; consequently, the Board encouraged the FAA to include maintenance procedures

and crew checklist operational procedures in its survey.

On March 5, 2004, the Safety Board reiterated Safety Recommendation A-02-25

as a result of its investigation of the January 8, 2003, Beech 1900D accident (Air Midwest

flight 5481) in Charlotte, North Carolina.96 The Boardís investigation found that the

captainís and the copilotís audio panel information was fair to poor quality with respect to

the audio captured from the accident airplaneís VHF radio systems. As a result, important

CVR information from the accident flight might not have been available if the audio

information from the captainís and the copilotís hot microphones had not been excellent to

good quality.

On June 7, 2005, the FAA responded that, even though CVRs on all equipped

airplanes were tested daily, the level of testing that the Safety Board was seeking could not

be universally accomplished because of implementation or design limitations imposed by

the regulations that govern CVR requirements. The FAA also stated that it issued Notice

N8000.292, ìClarification of Recommendations for Cockpit Voice Testingî

96 For more information, see National Transportation Safety Board, Loss of Pitch Control During

Takeoff, Air Midwest Flight 5481, Raytheon (Beechcraft) 1900D, N233YV, Charlotte North Carolina,

January 8, 2003, Aircraft Accident Report NTSB/AAR-04/01 (Washington, DC: NTSB, 2004).
Factual Information 39 Aircraft Accident Report

(January 18, 2005), for operators of those airplanes equipped with CVRs that can be tested

before the first flight of the day. The FAA indicated that the intent of the notice was to

persuade the operators to configure the CVRs during future major maintenance cycles so

that flight crews would be able to test them. Further, the FAA stated that it made a change

to FAA Order 8300.10, Airworthiness Inspectorís Handbook, Chapter 143, ìMonitor

Cockpit Voice Recordersî (March 4, 2004). According to the FAA, the change tasked

airworthiness aviation safety inspectors to evaluate maintenance programs that require

maintenance technicians to perform a thorough test of the CVR at appropriate intervals.

The FAA explained that the test should include listening to the recorder signals on each

channel to verify that the audio is properly recording, is intelligible, and does not contain

electrical noise or other interference.

On January 4, 2006, the Safety Board stated that, even though Notice N8000.292

asked for the recommended action, a notice was not a requirement, and it would expire

after 1 year. The Board added that the need for a functional check of the CVR before the

first flight of each day would remain after Notice N8000.292 was canceled. Also, the

Board stated that the change to FAA Order 8300.10 would not ensure that a CVR

functional test would be performed before the first flight of each day and that there must

be a permanent change to the FAAís operational requirements to ensure this CVR

functional test; such a change could be achieved by a revision to FAA Order 8400.10, Air

Transportation Operations Inspectorís Handbook. Pending this permanent change, Safety

Recommendation A-02-25 was classified ìOpenóAcceptable Response.î

1.18.6.2 Safety Recommendations A-06-17 and A-06-18

On March 7, 2006, the Safety Board issued Safety Recommendations A-06-17 and

A-06-18, which asked the FAA to do the following: 

Require all rotorcraft operating under 14 Code of Federal Regulations Parts 91

and 135 with a transport-category certification to be equipped with a cockpit voice

recorder (CVR) and a flight data recorder (FDR). For those transport-category

rotorcraft manufactured before October 11, 1991, require a CVR and an FDR or

an onboard cockpit image recorder with the capability of recording cockpit audio,

crew communications, and aircraft parametric data. (A-06-17)

Do not permit exemptions or exceptions to the flight recorder regulations that

allow transport-category rotorcraft to operate without flight recorders, and

withdraw the current exemptions and exceptions that allow transport-category

rotorcraft to operate without flight recorders. (A-06-18)
40 Aircraft Accident Report

2. Analysis

2.1 General

The captain and the copilot were properly certificated and qualified under Federal

regulations. No evidence indicated any medical or behavioral conditions that might have

adversely affected their performance during the accident flight. Flight crew fatigue was

not a factor in this accident.

The accident helicopter was properly certified, equipped, and maintained in

accordance with Federal regulations. The recovered components, with the exception of the

CVR,97 showed no evidence of any structural, engine, or system failures.

The engines were found attached to the helicopter with no evidence of fire,

uncontainment, structural damage, or foreign object damage. The torsion fractures to the

drive shafts and the water impact damage to the helicopter fuselage indicated that both

engines were producing power at the time of impact. During the helicopterís impact with

the water, the engines became decoupled from the transmission. As a result, the right

engine sensed an overspeed condition, shut down, and removed the overspeed protection

from the left engine, which, in turn, caused the left engine to overspeed.

All four main rotor blades were found fractured but with their root ends still

attached to the main rotor hub. All of the main rotor blade tips were recovered in the main

debris field. Two of the tail rotor blades were fractured just outside of the tail rotor cuff,

and a third tail rotor blade had fractured near the root but was still attached to the spar. The

fourth tail rotor blade had an outboard portion that was not recovered. None of the tail

rotor tips were recovered. However, because of the paddle design of the tail rotor blades, if

a tail rotor blade tip had separated in flight, a whole paddle (two tail rotor blades) would

be missing, which did not occur in this accident.

Weather was not a factor in this accident. The dispatcher who handled the accident

flight provided appropriate flight-tracking services. The search and rescue effort for this

accident was timely. The accident was not survivable for the helicopter occupants because

they were subjected to impact forces that exceeded the limits of human tolerance.

This analysis discusses the accident sequence, cockpit systems, tracking of Gulf of

Mexico helicopter flights, the lack of adequate CVR information for this accident

investigation, and the lack of FDR data for helicopter operations.

97 This issue is discussed in section 2.5.
Analysis 41 Aircraft Accident Report

2.2 Accident Sequence

2.2.1 Accident Summary

The Era Aviation dispatcherís records showed that the accident helicopter

departed GLS about 1845 with 2 hours of fuel on board. The helicopterís initial

destination was High Island A-557, a refueling platform about 80 nm south-southeast of

GLS, and its final destination was the Discoverer Spirit, a drilling ship that was en route to

a location about 180 miles south-southeast of GLS. It is reasonable to assume that the

captain was the flying pilot because, according to the CVR recording, the copilot was

making the radio calls to the dispatcher (which is the duty of the nonflying pilot) through

the time of the destination change. (The CVR did not record any pilot transmissions after

that time.)

ASR-9 radar data showed that the helicopter began to descend from an altitude of

1,800 feet at 1858:10 at a rate of 300 fpm. The last radar return that was received while the

helicopter was still within the range of radar coverage was at 1900:21; this return showed

that the helicopter was at an altitude of 1,100 feet msl and that its rate of descent was

250 fpm. At the time, the helicopter was located 35 nm south-southeast of GLS. If the

helicopter had continued its 250-fpm descent from 1,100 feet msl, it would have crashed

into the water within 5 minutes. However, the helicopter flew for another 18 minutes.

During its 1914 position report, the flight crew told the dispatcher that the

helicopter had enough fuel on board (1.6 hours) to continue directly to the location of the

Discoverer Spirit. The CVR study for this accident found that, at 1918:15, an increase of

torque was applied to the main rotor transmission and that the background noise level on

the CVR recording decreased from about 1918:25 to the end of the recording at 1918:34

(the time of the accident). Although an increase in torque can be the result of a pilot input

to the flight control system (increased collective or movement of the cyclic) and the

decrease in background noise level can be directly related to a decrease in forward

airspeed, the available evidence prevented further evaluation of the CVR studyís findings.

Evening civil twilight (sometime after which complete darkness occurs) ended

about 22 minutes before the accident. Also, the moon illumination (only 8 percent of the

moon disk) and the starlight were affected by a scattered to broken layer of low stratiform

clouds over the Gulf of Mexico south of GLS. The Safety Board concludes that, even

though VMC prevailed at the time of the accident, few, if any, references outside of the

helicopter would have been available to the flight crew.

The severe accordion-type crushing found on the helicopter fuselage was

consistent with a water impact at a high airspeed. The upward compression fractures

found on the lower fuselage were consistent with a level (or very shallow) bank attitude at

impact. The lack of damage to the lower part of the tailboom was consistent with a

shallow descent angle and pitch attitude at impact. The damage to the cyclic, collective,

and tail rotor pedal control systems was consistent with static overload fractures as a result

of water impact. As a result, the Safety Board concludes that the helicopter crashed into
Analysis 42 Aircraft Accident Report

the water at a high airspeed, a shallow descent angle, and a near-level roll attitude. Also,

because the main landing gear floats were found folded, which was consistent with the

floats not being inflated and being in the stowed position inside the wheel wells at impact,

and no emergency or distress calls were received by the dispatcher from the flight crew,

the Safety Board concludes that the pilots were not attempting an emergency landing on

the water. In addition, because of the inward crushing that was found on the lower part of

the structure that attached the fuselage and tailboom and the tearing that was found on the

upper part of the attachment structure, the Safety Board concludes that, after the helicopter

crashed into the water, the fuselage pitched nose down, and the tailboom broke off in a

downward direction.

Because no evidence showed any problems with the helicopterís engines, systems,

or structures during the accident flight, the Safety Boardís investigation focused on the

pilotsí actions during the 4 minutes between their last radio call to the dispatcher and the

time of the accident. The Board did not have FDR, CVR, or air traffic control

information98 to help determine what transpired during that portion of the flight. However,

with the use of an S-76A simulator that was similarly configured to the accident

helicopter, the Board examined numerous possible scenarios in which the flight crewís

actions could have inadvertently led to a controlled descent into water. The Board then

focused on the four scenarios that were the most likely to have occurred (see appendix C).

The scenario results, along with preaccident photographs of the accident helicopterís front

instrument panel and manufacturer and company manuals, showed the indications of

descent that would have been available to the flight crew. These indications are discussed

and analyzed in section 2.2.2.

2.2.2 Indications of Descent and Proximity to the Water

Cockpit instrumentation at both pilot stations would have shown indications of the

helicopterís descent and proximity to the water. These indications, which are shown in

figure 9 and described in this section, were located in front of the pilots and within their

routine instrument scan.

Three indications would have been available on a continuous basis throughout the

flight and did not require previous pilot action. First, the VSI needles (numbers 4 and 6 in

figure 9) would have been consistently below the centerline position, indicating a descent.

Second, the barometric altimeter needles (numbers 3 and 8 in figure 9) would have been

indicating a decreasing altitude. Third, the radar altitude readout on the ADIs (numbers 2

and 7 in figure 9) would have shown numbers that decreased in 10-foot increments

through 200 feet and 5-foot increments afterward.

98 As stated previously, the accident helicopter was not equipped with an FDR. Also, although the

helicopter was equipped with a CVR, three channels (including the pilot and copilot stations) contained no

usable information, and the fourth channel (the CAM) contained information that was mostly obscured by a

high level of background noise. In addition, no radar data were available after the helicopter descended

below 1,100 feet msl. 
Analysis 43 Aircraft Accident Report

Another indication, a rising runway symbol on the ADIs (numbers 2 and 7 in

figure 9), did not require previous pilot action but would not have appeared until 180 feet

above ground level (agl). The rising runway symbol would have continued upward until it

met the aircraft symbol on the ADIs at 0 feet.

In addition to the indications of the helicopterís descent and proximity to the water

that would have been present regardless of pilot action, several indications could have

been present depending on the actions taken by the pilots during the accident flight. For

example, if the flight crew had set a decision height above 0 feet (a decision height of

Figure 9. Indications of Descent in the Accident Helicopterís Cockpit

Source: Era Aviation.

1. Landing gear warning light

2. Captain’s ADI, showing radar altitude readout, rising runway symbol, decision height box, 

 decision height indication, and command cues

3. Captain’s barometric altimeter and altitude alert light

4. Captain’s VSI

5. Landing gear warning light

6. Copilot’s VSI

7. Copilot’s ADI, showing radar altitude readout, rising runway symbol, decision height box, 

 decision height indication, and command cues

8. Copilot’s barometric altimeter

2 3 4 5

7 6

8 1
Analysis 44 Aircraft Accident Report

200 feet was required by Era Aviation for nighttime flights), two additional indications of

the helicopterís descent and proximity to water would have been available. First, a

decision height box would have appeared on the ADIs (numbers 2 and 7 in figure 9) at

100 feet above the set decision height. Second, the letters DH would have appeared inside

the decision height box as the helicopter descended through the decision height. If the

decision height was set to 0 feet, a decision height box would have appeared on the ADIs

at 100 feet agl, and the letters DH would have appeared inside the decision height box

about the time that the helicopter was contacting the water. If the pilots had set different

decision heights, then the decision height box and the letters DH would have appeared

when the helicopter descended through the higher of the two decision heights. 99

Also, if either pilot had set a decision height above 0 feet, both pilots would have

seen conspicuous (very bright) landing gear warning lights under the glareshield panel100

(numbers 1 and 5 in figure 9) and would have heard a tone over their headsets when the

helicopter descended below the decision height.101 The aural tone was not detected on the

CVR recording. However, as stated previously, audio information from the pilot and

copilot stations was unusable because of the faulty installation of the CVR. Also, the

CAM would not have recorded the aural tone because the tone is sent to the pilotsí

headsets only and not to a cockpit speaker.

In addition, if the pilots had entered a preselected altitude on the AL-300, an

altitude alert light would have illuminated on the captainís barometric altimeter (number 3

in figure 9) at 1,000 feet above the preselected altitude. The light would have extinguished

from about 300 feet above to about 300 feet below the preselected altitude. The light

would again have illuminated from about 300 to 1,000 feet below the preselected altitude.

The pilots would have also heard a 1-second tone over their headsets each time that the

light illuminated.

Finally, if the pilots had selected an altitude-related flight director mode (altitude

or altitude preselect and vertical speed)102 but had not coupled the flight director to the

engaged autopilot, the pitch command cue would have been displaced above the centerline

on the ADIs (numbers 2 and 7 in figure 9). Displacement of the pitch command cue above

the centerline would have indicated that the helicopter was below the desired altitude, and

movement of the pitch command cue toward the top of the display would have indicated

99 If the accident flight crew had not changed the decision height from the previous flight, then the

altitude at which the decision height box and the DH indication appeared would have been based on the

decision height set by the previous flight crew.

100 The results of the landing gear warning light bulb examination were inconclusive regarding whether

the lights had illuminated. It is possible that the helicopter fuselage absorbed a large amount of impact

energy at the time of the collision with the water and that a reduced amount of impact energy was transferred

to the light bulbs within the helicopter. Thus, if the lights were illuminated at the time of impact, the impact

might not have been severe enough to stretch the filaments.

101 As stated in section 1.12.3, the landing gear relay could not be functionally tested after the accident to

determine if the system did in fact trigger because of damage to the relay that appeared to be the result of

seawater immersion.

102 If the pilots had selected the altitude preselect and vertical speed modes, they would also have had to

enter the desired altitude on the AL-300.
Analysis 45 Aircraft Accident Report

the helicopterís continued descent. Displacement of the pitch command cue in these cases

would have occurred regardless of whether a flight director heading mode was engaged

and the decision not to couple was intentional.

The Safety Board cannot determine the sequence of events that led to the

helicopterís inadvertent descent.103 It is clear, however, that the flight crew should have

been actively monitoring cockpit instrumentation showing the helicopterís altitude,

especially because of the lack of outside visual references. The flight crew would have

been presented with salient cues to detect the helicopterís descent and proximity to the

water. Thus, the Safety Board concludes that the flight crew was not adequately

monitoring the helicopterís altitude and missed numerous cues to indicate that the

helicopter was inadvertently descending toward the water.

2.2.3 Human Factors 

The Safety Board examined possible factors to explain why the flight crew missed

indications of the helicopterís descent and proximity to the water. Three of these factorsó

flight crew experience, crew coordination, and use of automated systemsóare discussed

in sections 2.2.3.1 through 2.2.3.3, respectively.

2.2.3.1 Flight Crew Experience

The accident flight crew had adequate experience in the accident helicopter and

other similar S-76A helicopters in Era Aviationís fleet to safely conduct the accident

flight. The captain and the copilot completed recurrent training and flight checks during

the month before the accident. Even though the captain completed his flight check in an

S-76A analog helicopter, he had line experience during the 12 months before the accident

with the S-76A EFIS-DDAFCS configuration, including experience with the accident

helicopter. The copilot completed his flight check in the accident helicopter and had

additional line experience during the 12 months before the accident with the

EFIS-DDAFCS configuration and the accident helicopter. Also, both pilots had adequate

experience at night to safely conduct the accident flight. In addition, both pilots received

adequate CFIT training.

2.2.3.2 Crew Coordination

The accident occurred about 4 minutes after the flight crew notified the dispatcher

of the change in destination. Under most conditions, a change in destination increases

pilot workload depending on the tasks that need to be completed and the flight conditions.

The accident flight crewís decision to proceed directly to the reported location of the

Discoverer Spirit required the pilots, at a minimum, to coordinate a change in course and

communicate with the dispatcher to receive updated coordinates for the ship, which would

have been programmed into the GPS after the course change. It is also possible that the

103 Even though an FDR was not required to be installed on the accident helicopter, an FDR would have

provided investigators with pertinent information to help determine the sequence of events that led to this

accident. The lack of a requirement for FDRs aboard helicopters is discussed in section 2.6.
Analysis 46 Aircraft Accident Report

flight crew initiated a change in control from one pilot to the other or a change in flight

control method from automatic (coupling of the autopilot and flight director) to manual

flight or vice versa. Such changes require effective crew coordination, including

continuous crosschecking and monitoring of instruments to ensure that the intended

system inputs have correctly been made.

The accident flight was the first one that paired the captain and the copilot.

Coordinating with a new flight crewmember can require more effort than coordinating

with a previous crewmember. Also, new crew pairings have been associated with

increased errors and less effective communication patterns than crew pairings with

crewmembers who have previously flown together.104 During critical phases of flight, a

lack of familiarity can affect a flight crewís ability to coordinate effectively. However,

because of the poor quality of the CVR recording, it was not possible for the Safety Board

to determine whether crew coordination was a factor in this accident.

2.2.3.3 Use of Automated Systems

The accident helicopterís flight control system allowed the pilot to couple the

autopilots and flight director so that the helicopter would automatically carry out pilot-set

flightpath commands. The pilots might have intended to use this feature to automatically

maintain heading and altitude while they completed some immediate manual tasks related

to the change in destination. However, the pilots could have incorrectly programmed the

flight director mode selector and either not have detected this situation or have

misinterpreted it given the available system feedback (as discussed in section 2.3.2). It is

also possible that the pilots were in the process of reprogramming the flight director mode

selector. Research on the use of automated flight systems in transport-category aircraft

found that the reprogramming of automated flight control systems is prone to human error

because reprogramming involves multiple, complex steps.105

The accident pilots might not have chosen to use the coupling feature when

changing destinations and instead might have chosen to rely on their ability to manually

maintain the appropriate flightpath. The helicopterís ATT mode provides stability to the

helicopter during manual flight and reduces a pilotís manual control requirements. If the

helicopter were descending at a shallow rate, the ATT mode would have maintained this

trajectory with minimal, if any, physical cues.

One of the most critical issues associated with flight deck automation is

ìautomation misuse,î that is, pilot overreliance on automation, because it can lead to

deficiencies in monitoring an aircraftís performance.106 Pilots may become complacent if

104 H.C. Foushee, J.K. Lauber, M.M. Baetge, and D.B. Acomb, Crew Factors in Flight Operations: III. 

The Operational Significance of Exposure to Short-Haul Air Transport Operations, National Aeronautics

and Space Administration Technical Memorandum 88322 (August 1986).

105 R.O. Besco and K. Funk, ìConceptual Design Guidelines to Rediscover Systems Engineering for

Automated Flight Decks,î International Journal of Aviation Psychology, Vol. 9, No. 2 (2000): 189-198.

106 R. Parasuraman and V. Riley, ìHumans and Automation: Use, Misuse, Disuse, Abuse,î Human

Factors, Vol. 39, No. 2 (1997): 230-253.
Analysis 47 Aircraft Accident Report

they are overconfident in automation and may fail to exercise appropriate vigilance.107 As

a result, significant deviations in altitude or flightpath, if controlled by automation, may

develop without detection by the flight crew, especially when the flight crew is focused on

other tasks. The only reliable way for pilots to detect such deviations is through

continuous monitoring of cockpit instrumentation. Although the opportunity for

successful monitoring would be increased with two flight crewmembers rather than an

individual pilot, research indicated that an overreliance on automation and a failure to

monitor were unaffected by the presence of a second pilot in the cockpit.108

Evidence was not available for the Safety Board to determine whether the accident

pilots were relying on an automated system for altitude and flightpath control.

Nevertheless, the Board notes that, because the possibility exists for monitoring errors

when using automated systems (and from distractions during times of increased

workload), other systems have been developed to provide pilots with warnings of

impending conditions that require corrective actions. One such system is TAWS, which

alerts flight crews to a potential collision with terrain or water. Helicopters are not

currently required to be equipped with TAWS; this issue is discussed and analyzed in

section 2.3.1.

2.3 Cockpit Systems

2.3.1 Terrain Awareness and Warning System

TAWS has the ability to look ahead of an aircraft to detect the terrain or other

obstructions along a flightpath. However, none of the S-76A helicopters in Era Aviationís

fleet were equipped with a TAWS or were required to be so equipped.

At the time of the FAAís March 2000 final rule requiring that a TAWS be installed

aboard all turbine-powered airplanes configured with six or more passenger seats, TAWS

technology had not been specifically developed for the unique flightpaths of rotorcraft

compared with fixed-wing aircraft (that is, lower altitudes and the ability to land at

off-airport sites). Thus, the installation of TAWS aboard helicopters at that time would

have likely resulted in numerous false warnings; systems with this tendency typically

prompt a lack of operator trust and result in the failure to respond to the systemsí

warnings. However, TAWS technology is now available for helicopters,109 and this

technology can include warnings for terrain, obstacles, landing gear, excessive bank and

sink rates, tail low attitudes, and below glideslope (on an instrument approach). 

107 K. Funk, B. Lyall, J. Wilson, R. Vint, M. Niemczyk, C. Suroteguh, and G. Owen, ìFlight Deck

Automation Issues,î International Journal of Aviation Psychology, Vol. 9, No. 2 (2000): 109-123. 

108 L.J. Skitka, K.L. Mosier, M. Burdick, and B. Rosenblatt, ìAutomation Bias and Errors: Are Crews

Better Than Individuals?,î International Journal of Aviation Psychology, Vol. 10, No. 1 (2000): 85-97.

109 For example, Honeywellís Mark XXII enhanced GPWS, which was certified in 2001, contains an

obstacle database that includes locations of more than 5,000 oil platforms and structures in the Gulf of

Mexico. Also, during its visit to PHI, the Safety Board learned that the company equipped its helicopters

with TAWS upon customer request. 
Analysis 48 Aircraft Accident Report

A simulation by the manufacturer of TAWS for helicopters showed that, if a

TAWS had been installed aboard the accident helicopter and the helicopter were

descending toward the water at a rate of 150 fpm, the ìcaution terrainî alert would have

occurred 97 seconds before impact at an altitude of about 240 feet, along with a water

indication that changed from blue to yellow on the systemís forward-looking terrain

awareness display. The simulation also showed that the ìwarning terrainî alert would

have occurred 84 seconds before impact at an altitude of about 210 feet, along with a

water indication that changed from yellow to red on the forward-looking terrain awareness

display. If the helicopter were descending toward the water at a rate of 250 fpm, the

caution terrain alert would have occurred 68 seconds before impact at an altitude of about

270 feet, and the warning terrain alert would have occurred 55 seconds before impact at an

altitude of about 215 feet (along with the water indication color changes on the

forward-looking terrain awareness display).

The Safety Board concludes that, if a TAWS had been installed aboard the

accident helicopter, the systemís aural and visual warnings should have provided the flight

crew with ample time to recognize that the helicopter was descending toward the water,

initiate the necessary corrective actions, and recover from the descent. Therefore, the

Safety Board believes that the FAA should require all existing and new U.S.-registered

turbine-powered rotorcraft certificated for six or more passenger seats to be equipped with

a TAWS.

As part of its special investigation report on EMS aircraft accidents, the Safety

Board issued Safety Recommendation A-06-15, which asked the FAA to require EMS

operators to install TAWS on their aircraft. It is important to provide the same level of

safety for other helicopter operations, including the transportation of oil service personnel

to and from offshore platforms. 

2.3.2 Dual Digital Automatic Flight Control System

The accident helicopter was equipped with an SPZ-7000 DDAFCS. Although the

Safety Board found no evidence to indicate that the SPZ-7000 contributed to this accident,

the Board noted three characteristics about this flight control system that have

safety-of-flight implications if pilots are not familiar with the system.

First, the SPZ-7000 does not provide an indication on the ADIs showing which

flight director (FD1 or FD2) has been engaged. The SPZ-7000 has two independent

flight control computers; one computer provides commands to the autopilot and flight

director at the pilotís station, and the other computer provides commands to the

autopilot and flight director at the copilotís station (referred to as a split cockpit). Thus,

it is possible for the pilot and copilot ADIs to simultaneously present a different set of

pitch and roll command cues.110 This situation can be beneficial if the nonflying pilot

110 In contrast, many of the flight control systems currently in use in transport-category fixed-wing

aircraft have dual but dependent flight control computers. In such systems, only one set of commands guides

flight director command cues, which are presented simultaneously for both pilot stations.
Analysis 49 Aircraft Accident Report

wants to program the flight director in advance of the subsequent phase of flight.

However, only one pilot station can be coupled at a time, and a lack of pilot awareness

regarding which set of command cues is coupled to the autopilot can lead to automation

mode confusion.111

Two indications in the cockpit provide the pilot with direct feedback regarding the

flight director status: the FD1/2 button on the autopilot controller on the center pedestal

(see figure 2), which shows the flight director that has been engaged, and the CPLT FD

light (see number 9 in figure 1), which illuminates on the caution/advisory panel on the

center of the front instrument panel when FD1 is selected. No similar light illuminates

when FD2 is selected, and the only indication in front of the pilots that FD2 is selected is

the absence of illumination of the CPLT FD light. Neither the FD1/2 button nor the CPLT

FD light is located near either pilotís ADI or the flight director mode selector, where other

indications regarding flight director mode selections are presented.

Second, the SPZ-7000 does not annunciate the coupling status on the front

instrument panel and does not provide an aural alert when the autopilot and flight director

have become decoupled. As a result, the only direct indication of the coupling status is the

illumination, or absence of illumination, of the CPL light on the autopilot controller on the

center pedestal (see figure 2).

Although indirect indications of the flight director source and coupling status

can be determined through monitoring cockpit instrumentation, the possibility of

automation mode confusion increases when pilots are required to search multiple

locations for information pertaining to the same system.112 Displays for many newer

flight control systems, including those used on the Sikorsky S-92 and Agusta AB-139

helicopters, annunciate the flight director source and the coupling status directly on the

ADIs. 

Third, when only one flight director mode (either pitch or roll) is selected, both

pitch and roll command cues appear simultaneously on the SPZ-7000, but no annunciation

appears on the ADIs regarding the source of guidance for the unselected command cue.

Because the SPZ-7000 allows for independent engagement of flight director mode

selections (referred to as split-axis engagement), the system can be coupled to the

longitudinal (pitch), lateral (roll), and vertical axes individually, two at a time, or all three

simultaneously. The ability to engage only one or two axes, instead of all three, can be

beneficial in certain circumstances, such as search and rescue, when a pilot may engage a

roll function on the flight director mode selector (such as heading) but need to make pitch

control inputs to maintain a certain height above varying terrain. However, the

simultaneous presentation of command cues for both selected and unselected axes allows

for the possibility of pilot misinterpretation of the command cue for the unselected axis.

Specifically, a pilot may be unaware that a flight director mode has not been selected for

111 Automation mode confusion is a lack of awareness of the current mode of an automated system. It

can result from inadequate feedback about the automated systemís actions and intentions.

112 R. Parasuraman and V. Riley, ìHumans and Automation: Use, Misuse, Disuse, Abuse,î Human

Factors, Vol. 39, No. 2 (1997): 230-253.
Analysis 50 Aircraft Accident Report

both axes (because of the presence of two command cues)113 and thus not realize that the

command cue for the unselected axis is not synchronized to a selected pitch or roll

function.

Even if a pilot were aware that a flight director mode had not been selected for

both axes, the lack of an annunciation on the ADIs regarding the source of guidance for

the unselected axis might also result in pilot misinterpretation of the command cue. The

source of guidance for an unselected command cue varies between flight control system

models and may or may not be synchronized to the helicopterís attitude. For the

SPZ-7000, the command cue for an unselected axis is synchronized to the helicopterís

attitude. As a result, the command cue for the unselected axis will indicate a deviation

from attitude rather than a deviation from altitude (when a flight director roll function is

selected) and heading (when a flight director pitch function is selected).

Some of the FAAís observations of the SPZ-7000 DDFACS (see section 1.18.5.1)

were consistent with those made by the Safety Board. Specifically, the FAA found that

(1) no aural or visual annunciations occurred for a pilot-induced decouple, (2) the only

cues that the flight director was not coupled on the selected side were the lack of flight

director mode selections and the lack of flight director mode annunciations on the ADIs,

(3) both pitch and roll command cues were displayed when only one axis was selected,

and (4) the decoupling indications were not particularly compelling.

Although the SPZ-7000 is no longer in production, it is still in use on numerous

helicopters.114 The SPZ-7000ís successor is the SPZ-7600, which is installed in S-76C

helicopters.115 Although the SPZ-7600 has many of the same components and operations

as the SPZ-7000, the SPZ-7600 has key differences regarding coupling status

annunciation, which promotes pilot mode awareness. For example, although the

SPZ-7000 and the SPZ-7600 both have a DCPL warning indicator on the DAFCS caution

panels (which are in direct view of the pilots and are next to the ADIs) to indicate when

the autopilot and flight director have become decoupled, the SPZ-7000 DCPL warning

indicators illuminate only during abnormal operations, whereas the SPZ-7600ís DCPL

warning indicators illuminate during both normal and abnormal operations. Also,

although both the SPZ-7000 and the SPZ-7600 are not manufactured with an aural alert to

indicate system decoupling, operators of helicopters that are equipped with the SPZ-7600

can install an after-market product that provides this alert to the pilotsí headsets, the cabin,

or both.

The SPZ-7600 also has a key difference regarding command cue guidance for the

dual-cue format. With the SPZ-7000, both command cues appear simultaneously when

only one axis is engaged. However, with the SPZ-7600 dual-cue format, the command cue

for only the selected axis will appear on the pilotsí ADIs. Specifically, if a flight director

113 For the dual-cue format, pitch attitude is represented by a horizontal command bar, and roll attitude is

represented by a vertical command bar (see figure 7). For the single-cue format, pitch and roll guidance is

integrated into angular bars in the shape of a chevron (see figure 8).

114 According to a Honeywell official, more than 300 SPZ-7000s were manufactured.

115 A Honeywell official stated that more than 850 SPZ-7600s have been manufactured to date.
Analysis 51 Aircraft Accident Report

roll function, such as heading, is selected and no flight director pitch function is engaged,

only the vertical command bar (roll attitude) will appear. Likewise, if a flight director

pitch function, such as altitude, is selected and no flight director roll function is engaged,

only the horizontal command bar (pitch attitude) will appear. Thus, with the SPZ-7600

dual-cue format, pilots cannot misinterpret command cue guidance for the unselected axis,

which also promotes pilot mode awareness.

Despite the improvements present in the SPZ-7600 (compared with the

SPZ-7000), two issues exist with the single-cue format for that system. One issue is that

the guidance for the unselected axis is still presented without annunciation. As a result,

pilots could still misinterpret the status of the command cue for the unselected axis when

using the SPZ-7600 single-cue format. The other issue is that the command cue for the

unselected axis for the SPZ-7600 is not synchronized to attitude (as with the SPZ-7000);

instead, the single-cue format symbol maintains a centered or neutral position regardless

of pilot input. Thus, pilots may mistake a centered (pitch attitude) or neutral (roll attitude)

command cue as feedback that the aircraft is either on a commanded flightpath or is

synchronized to attitude (as with the SPZ-7000).116

Pilot mode awareness is a critical aspect associated with reducing errors from the

use of automated flight control systems.117 During postaccident interviews, Era Aviation

pilots (including the chief pilot and director of training) were not able to fully explain the

flight director and coupling status annunciations and command cue presentations

associated with the SPZ-7000 and SPZ-7600. Additional training on these systems could

help improve pilot understanding of the systemsí capabilities, which is especially critical

for pilots who operate both the SPZ-7000 and SPZ-7600. The Safety Board concludes that

additional pilot training on the SPZ-7000 and SPZ-7600 DDAFCSs would promote

automation mode awareness for pilots operating helicopters equipped with these systems.

Therefore, the Safety Board believes that the FAA should ensure that all operators of

helicopters equipped with either the SPZ-7000 or SPZ-7600 DDAFCSs provide training

that includes information on flight director and coupling status annunciations; the

command cue presentations when only the pitch or the roll mode is engaged; and, if

applicable, the differences between the SPZ-7000 and the SPZ-7600. 

2.4 Tracking of Gulf of Mexico Helicopter Flights

The FAA cannot currently provide flight-tracking services for low-flying aircraft

in the Gulf of Mexico beyond the capabilities of existing FAA land-based radar sites. For

example, during the accident flight, radar data were available until the helicopter was

about 58 nm southeast of the Houston ASR-9 radar site, which provides maximum radar

coverage of about 60 nm. The helicopter flew for another 18 minutes, traveling an

additional 35 nm to the southeast, but no radar data were available for that portion of the

116 Displays for some newer flight control systems annunciate the source of guidance for the unselected

axis (for example, ìROLLî or ìPTCHî) when the unselected axis is synchronized to attitude. 

117 U.S. Department of Transportation, Federal Aviation Administration, Report on the Interfaces

Between Flightcrews and Modern Flight Deck Systems (Washington, DC: FAA, 1996).
Analysis 52 Aircraft Accident Report

flight. In addition to the lack of radar data for low-flying aircraft in the Gulf of Mexico,

only helicopter dispatchers are aware of the status of their respective companyís flights

because there is no direct communication between pilots of such aircraft and air traffic

controllers.118

The FAAís Safe Flight 21 Gulf of Mexico initiative (see section 1.18.3) was

developed to determine whether ADS-B technology would be effective in providing pilots

with navigation, air traffic, terrain, and weather information in the cockpit and enabling air

traffic controllers and operators to provide surveillance (including position and altitude) of

low-flying aircraft in those areas with limited or no radar coverage. The ADS-B

infrastructure included ground-based transceivers, weather sensors, and communications

outlets that would be used along with ADS-B monitors installed by operators on aircraft

that fly in the Gulf of Mexico.

ADS-B technology had already been successfully deployed in Alaska as part of the

Safe Flight 21 Capstone program. The FAAís Capstone Web site indicated that, according

to a 2004 safety study by the University of Alaska, the accident rate for aircraft under the

Capstone program had decreased by 47 percent from 2000 to 2004. Also, according to a

2003 safety study contracted by the Capstone program,119 the ADS-B technology used in

the Capstone program would have been effective in preventing about 80 percent of the en

route CFIT accidents that occurred in southwest Alaska (the Phase I Capstone area)

between 1990 and 1999.120

The Capstone program and the Safe Flight 21 Gulf of Mexico initiative were both

intended to benefit pilots of low-flying aircraft in areas of limited radar coverage. The

final phase of the Capstone program is currently being developed with funding for site

surveys (but not for construction of the sites). However, in November 2005, the FAA

indicated that implementation of the Safe Flight 21 Gulf of Mexico initiative would not

begin until fiscal year 2013. As a result, helicopter pilots transporting oil service personnel

to and from offshore platforms would not be afforded the same level of safety as general

aviation pilots operating in Alaska.

ADS-B technology has many potential benefits for flight operations in the Gulf of

Mexico. For example, if the ADS-B infrastructure had been operational in the Gulf of

Mexico at the time of the accident, (1) the Era Aviation dispatcher would have had better

flight-tracking and communication capabilities and thus could have monitored the

accident helicopterís flightpath and provided an alert to the flight crew about the descent

118 For some helicopter operators, the status of their companyís flights is transmitted only intermittently

(as with Era Aviation, whose pilots provide dispatchers with position reports every 15 minutes.) As a result,

no continuous flight tracking is provided for such flights.

119 University of Alaska Anchorage, Capstone Phase I Interim Safety Study, 2002 (Anchorage, Alaska:

University of Alaska, 2003).

120 According to the study, the ADS-B technology should prevent en route CFIT accidents by providing

the pilot with information about the aircraftís proximity to high ground. Specifically, the technology

compares information about nearby terrain (stored in an on-board database) with the aircraftís altitude and

GPS location and then presents the information on a cockpit display. Terrain that is 500 feet or less below

the aircraft is shown in yellow, and terrain that is level with or higher than the aircraft is shown in red.
Analysis 53 Aircraft Accident Report

and (2) the pilots would have received a warning in the cockpit about the descent. Also,

ADS-B technology has many potential benefits for search and rescue operations in the

Gulf of Mexico. For example, in September 2005, a Houston Helicopters S-76A

helicopter was ditched in the Gulf of Mexico after an in-flight fire.121 The 2 pilots and

10 passengers escaped from the helicopter but remained in the water for about 7 hours

until they were located by U.S. Coast Guard personnel using night vision goggles.122

ADS-B technology would have facilitated the search and expedited the rescue of the

helicopter occupants. In addition, ADS-B technology would benefit accident

investigations because information on an aircraftís airspeed, altitude, and position (that is,

whether the aircraft was turning, climbing, or descending) would be available to

investigators.

In January 2006, the FAA announced that the Safe Flight 21 program was being

transitioned to the National ADS-B Program. At that time, the FAA proposed fiscal year

2007 for the start date for implementation of the program and fiscal year 2010 as the target

date for completion of the first segment of ADS-B infrastructure deployment. On

March 1, 2006, the FAA verbally informed the Safety Board that the Gulf of Mexico

would be among those areas in the first segment of ADS-B infrastructure deployment;

however, this information has not been confirmed.

It is critical that the milestones for the National ADS-B Program in the Gulf of

Mexico are achieved on or ahead of time and that the fiscal year 2010 completion date for

ADS-B deployment in the Gulf of Mexico not slip. This matter is especially important

given the number of passengers and flights in the region (in 2004, more than 2.3 million

passengers were transported aboard 1.3 million flights) and the inherent risks of offshore

helicopter operations, as indicated by the FAAís Aeronautical Information Manual,

section 10-2-1, ìOffshore Helicopter Operations,î which states the following: 

The offshore environment offers unique applications and challenges for helicopter

pilots. The mission demands, the nature of oil and gas exploration and production

facilities, and the flight environment (weather, terrain, obstacles, traffic), demand

special practices, techniques and procedures not found in other flight operations.

Because of the limited radar services in the Gulf of Mexico, some helicopter

operators, including Era Aviation, PHI, and Air Logistics, have purchased flight-tracking

systems from commercial vendors. These commercial systems allow dispatchers to track

aircraft in flight and the weather along the flightpath and to relay text messages to

company pilots (and vice versa). Thus, as with ADS-B technology, a commercial

121 For more information about this accident, see DFW05MA230 at the Safety Boardís Web site.

122 The pilot of the helicopter declared ìMAYDAYî but did not provide position information. Pilots of

several aircraft in the area overheard the emergency distress call and immediately notified various FAA

facilities of the situation. A ground search for the helicopter was then conducted based on the reported

locations of the aircraft pilots who had overheard the emergency distress call. After the helicopter was

overdue at its destination by more than 2 hours, the company coordinated with the FAA and the Coast Guard

to determine the helicopterís likely location, and the Coast Guard then began its search for the helicopter.

Because of damage to the communication infrastructure from Hurricane Katrina, company and FAA

communications were not available for the flight. 
Analysis 54 Aircraft Accident Report

flight-tracking system could have provided the Era Aviation dispatcher with information

about the accident helicopterís descending altitude, which she could have communicated

to the flight crew. However, the ADS-B technology would offer an additional level of

safety for pilots flying at low altitudes in the Gulf of Mexico by providing them with

navigation, air traffic, terrain, and weather information in the cockpit.

The Safety Board concludes that the National ADS-B Program technology would

help Gulf of Mexico aircraft operators mitigate the inherent risks associated with offshore

operations by providing pilots with terrain, weather, and other flight information in the

cockpit and dispatchers with current location information. Therefore, the Safety Board

believes that the FAA should ensure that the infrastructure for the National ADS-B

Program in the Gulf of Mexico is operational by fiscal year 2010. The Safety Board

further believes that, until the infrastructure for the National ADS-B Program in the Gulf

of Mexico is fully operational, the FAA should require POIs of Gulf of Mexico aircraft

operators to inform the operators about the benefits of commercial flight-tracking systems

and encourage the operators to acquire such systems.

2.5 Lack of Adequate Cockpit Voice Recorder 

Information for This Investigation

The accident helicopter was equipped with a CVR that had been improperly

installed. Specifically, the helicopterís CVR installation required that white notched

switches (within the internal communications system units for the pilot and copilot

stations) be set to the bottom position, but the switches were found set to the top position.

The failure to set the switches to the correct position resulted in a lack of audio input to

those CVR channels. The functional check of the CVR after installation did not detect the

faulty installation.

The CAM was the only source of audio information recorded for the accident

flight. However, because of the high noise level within the helicopter cockpit, the flight

crewís conversation was mostly unintelligible. The lack of audio information significantly

hindered the investigation of this accident.

On August 29, 2002, the Safety Board issued Safety Recommendation A-02-25,

which asked that the FAA require operators to implement daily CVR test procedures to

prevent the lack of CVR data after aviation accidents and incidents (see section 1.18.6.1).

On March 5, 2004, the Safety Board reiterated Safety Recommendation A-02-25 as a

result of its investigation of the January 2003 Air Midwest Beech 1900D accident in

Charlotte. The Boardís investigation of that accident found that the captainís and the

copilotís audio information captured from the airplaneís VHF radio systems was fair to

poor quality.

In its response to Safety Recommendation A-02-25, the FAA stated that it issued

Notice N8000.292, ìClarification of Recommendations for Cockpit Voice Recorder

Testing,î for operators of those airplanes equipped with CVRs that could be tested before
Analysis 55 Aircraft Accident Report

the first flight of the day. The FAA indicated that the intent of the notice was to persuade

the operators to configure the CVRs during future major maintenance cycles so that flight

crews would be able to test them. The FAA also stated that it made a change to

chapter 143, ìMonitor Cockpit Voice Recorders,î of FAA Order 8300.10. According to

the FAA, the change tasked airworthiness aviation safety inspectors to evaluate

maintenance programs that require maintenance technicians to perform a thorough test of

the CVR at appropriate intervals. The Safety Board classified Safety

Recommendation A-02-25 ìOpenóAcceptable Responseî pending a permanent change

to the FAAís operational requirements to ensure that a CVR functional test would be

performed before the first flight of each day.

Although daily preflight testing of the CVR should catch most problems

encountered with poor-quality audio recordings, a review of the actual audio recorded by

the CVR would ensure that the entire CVR system (including the microphones,

audio/communications panels, wiring, and CVR itself) was working properly. Such a

review would reveal any problems with audio quality, CVR malfunction, or lack of audio

signals to the CVR. The Safety Board recognizes that a review of downloaded audio data

would not be feasible on a daily preflight basis, but this review could easily be

accomplished periodically during a routine maintenance check of an aircraft.

A periodic maintenance check of a CVR could be similar to the periodic

maintenance check that is performed on an FDR, during which the FDR is downloaded

and the data are analyzed to ensure that the required parameters are being recorded

correctly. The FDR maintenance check is currently being accomplished with minimal

impact on the amount of time that the recorder is removed from the aircraft. With the

advent of solid-state recorders, the download can be accomplished without the operator

having to perform any maintenance to the recorder to comply with the download

requirement.

The Safety Board concludes that preflight testing and maintenance checks of an

aircraftís CVR are both necessary to ensure that audio data from CVR recordings are

adequate. Therefore, the Safety Board believes that the FAA should require all operators

of aircraft equipped with a CVR to (1) test the functionality of the CVR before the first

flight of each day as part of an approved aircraft checklist and (2) perform a periodic

maintenance check of the CVR as part of an approved maintenance check of the aircraft.

The CVR preflight test should be performed according to procedures provided by the

CVR manufacturer and should include listening to the recorded signals on each channel to

verify that the audio is being recorded properly, is intelligible, and is free from electrical

noise or other interference. The periodic maintenance check of the CVR should include an

audio test followed by a download and review of each channel of recorded audio. The

downloaded recording should be checked for overall audio quality, CVR functionality,

and intelligibility.

In addition, the FAAís actions in response to Safety Recommendation A-02-25ó

the issuance of Notice N8000.292 and the change to FAA Order 8300.10óare not

adequate to ensure that a CVR, once installed, will operate as required because the CVR

test detailed in the notice and the order might not contain sufficient instructions to detect
Analysis 56 Aircraft Accident Report

all faulty recordings. For example, although the preflight test recommended in Safety

Recommendation A-02-25 might have been sufficient to discover the problem with the

CVR installed on the Air Midwest accident airplane, the preflight test would not have

discovered the faulty CVR installed on the Era Aviation accident helicopter. Therefore,

the Safety Board classifies Safety Recommendation A-02-25 ìClosedóSupersededî as a

result of the issuance of Safety Recommendation A-06-23.

2.6 Lack of Flight Data Recorder Information for 

Helicopter Operations

The accident helicopter was not equipped with an FDR. In August 2003, the

S-76A and several other helicopter models became permanently exempt from

14 CFR 135.152, which required that multiengine, turbine-powered aircraft with 10 to 19

passenger seats (excluding required crewmember seats) be equipped with an FDR.

In June 2001, Era Aviation requested a temporary exemption from the

requirements of 14 CFR 135.152 for two of its S-76A helicopters (one of which was the

accident helicopter) while the FAA was in the process of changing the regulation. In its

letter, Era Aviation stated that operations without FDRs ìdo not degrade safety.î The

letter also stated that the Safety Boardís accident data for rotorcraft operated under

Part 135 with seating of 10 to 19 passengers do not indicate ìthat the cause of accidents is

in question or that the investigative process would have been improved by the requirement

for a DFDR.î

In its August 2001 letter to Era Aviation that granted the exemption, the FAA cited

Grant of Exemption No. 6785, which stated that the FAA had found that operators had

demonstrated ìvalid reasonsî for exempting several helicopter models (including the

S-76A) from the FDR requirements, but the letter did not state what these valid reasons

were. The FAAís letter also stated, ìexempting certain helicopters from the FDR

requirements would be in the public interest and would not adversely affect safety.î

The Safety Board does not agree with the FAAís position that the lack of an FDR

aboard helicopters is in the public interest and does not adversely affect safety. An FDR is

an important investigative tool that is used to determine an aircraftís performance.

Because the information that investigators learn from FDR data can help prevent accidents

and incidents from recurring, the lack of FDRs aboard helicopters undoubtedly affects

safety.

The Safety Board also disagrees with Era Aviationís position that, according to

helicopter accident data, the investigative process would not be improved by the

requirement for an FDR. The lack of FDR information hindered the Boardís investigation

of this accident, especially because of the poor quality of the CVR recording and the

limited radar data. If an FDR had been installed on the accident helicopter, pertinent

information would have been available to investigators, including the helicopterís

flightpath, engine operation, autopilot operation, and flight control inputs.
Analysis 57 Aircraft Accident Report

The investigation of the August 2005 accident involving an S-76C that crashed in

the Baltic Sea shortly after takeoff from Tallinn, Estonia, demonstrated that recorded

flight data for helicopter operations are critical for effective accident and incident

investigations. The S-76C had an FDR installed, and FDR data showed that the

helicopterís pitch and roll movements were severe during the accident sequence and were

not consistent with the recorded cyclic inputs. It is likely that the helicopterís movement

and the cyclicís movement would not have been known without the FDR data. As a result,

investigators identified airworthiness concerns about S-76 actuators because the FDR data

were consistent with a loss of control of the forward actuator. 

The Estonian accident was the first one involving a large helicopter for which FDR

data were available. The FDR data have been extremely valuable during the investigation

of that accident, which clearly demonstrates the possibility that FDR data for previous

accidents would have been equally valuable if these data had been available.

The Safety Board concludes that, because the FAA exempted the S-76A helicopter

from the FDR requirements in 14 CFR 135.152, recorded flight data were not available to

help reconstruct the events that led to this accident, which significantly hampered the

investigation. To prevent a similar situation from recurring, the Board urges the FAA to

act on Safety Recommendations A-06-17 and -18 (see section 1.18.6.2) in a timely

manner. 
58 Aircraft Accident Report

3. Conclusions

3.1 Findings

1. The captain and the copilot were properly certificated and qualified under Federal

regulations. No evidence indicated any medical or behavioral conditions that might

have adversely affected their performance during the accident flight. Flight crew

fatigue was not a factor in this accident.

2. The accident helicopter was properly certified, equipped, and maintained in

accordance with Federal regulations. The recovered components, with the exception

of the cockpit voice recorder, showed no evidence of any structural, engine, or system

failures.

3. Weather was not a factor in this accident. The dispatcher who handled the accident

flight provided appropriate flight-tracking services. The search and rescue effort for

this accident was timely. The accident was not survivable for the helicopter occupants

because they were subjected to impact forces that exceeded the limits of human

tolerance.

4. Even though visual meteorological conditions prevailed at the time of the accident,

few, if any, references outside of the helicopter would have been available to the

flight crew.

5. The helicopter crashed into the water at a high airspeed, a shallow descent angle, and

a near-level roll attitude.

6. The pilots were not attempting an emergency landing on the water.

7. After the helicopter crashed into the water, the fuselage pitched nose down, and the

tailboom broke off in a downward direction.

8. The flight crew was not adequately monitoring the helicopterís altitude and missed

numerous cues to indicate that the helicopter was inadvertently descending toward the

water.

9. If a terrain awareness and warning system had been installed aboard the accident

helicopter, the systemís aural and visual warnings should have provided the flight

crew with ample time to recognize that the helicopter was descending toward the

water, initiate the necessary corrective actions, and recover from the descent.

10. Additional pilot training on the SPZ-7000 and SPZ-7600 dual digital automatic flight

control systems would promote automation mode awareness for pilots operating

helicopters equipped with these systems.
Conclusions 59 Aircraft Accident Report

11. The National Automatic Dependent SurveillanceñBroadcast Program technology

would help Gulf of Mexico aircraft operators mitigate the inherent risks associated

with offshore operations by providing pilots with terrain, weather, and other flight

information in the cockpit and dispatchers with current location information.

12. Preflight testing and maintenance checks of an aircraftís cockpit voice recorder

(CVR) are both necessary to ensure that audio data from CVR recordings are

adequate.

13. Because the Federal Aviation Administration exempted the S-76A helicopter from the

flight data recorder requirements in 14 Code of Federal Regulations 135.152,

recorded flight data were not available to help reconstruct the events that led to this

accident, which significantly hampered the investigation.

3.2 Probable Cause

The National Transportation Safety Board determines that the probable cause of

this accident was the flight crewís failure to identify and arrest the helicopterís descent for

undetermined reasons, which resulted in controlled flight into terrain.
60 Aircraft Accident Report

4. Recommendations

4.1 New Recommendations

As a result of the investigation of this accident, the National Transportation Safety

Board makes the following recommendations to the Federal Aviation Administration:

Require all existing and new U.S.-registered turbine-powered rotorcraft

certificated for six or more passenger seats to be equipped with a terrain

awareness and warning system. (A-06-19)

Ensure that all operators of helicopters equipped with either the SPZ-7000

or SPZ-7600 dual digital automatic flight control systems provide training

that includes information on flight director and coupling status

annunciations; the command cue presentations when only the pitch or the

roll mode is engaged; and, if applicable, the differences between the

SPZ-7000 and the SPZ-7600. (A-06-20)

Ensure that the infrastructure for the National Automatic Dependent

SurveillanceñBroadcast Program in the Gulf of Mexico is operational by

fiscal year 2010. (A-06-21)

Until the infrastructure for the National Automatic Dependent

SurveillanceñBroadcast Program in the Gulf of Mexico is fully operational,

require principal operations inspectors of Gulf of Mexico aircraft operators

to inform the operators about the benefits of commercial flight-tracking

systems and encourage the operators to acquire such systems. (A-06-22)

Require all operators of aircraft equipped with a cockpit voice recorder

(CVR) to (1) test the functionality of the CVR before the first flight of each

day as part of an approved aircraft checklist and (2) perform a periodic

maintenance check of the CVR as part of an approved maintenance check

of the aircraft. The CVR preflight test should be performed according to

procedures provided by the CVR manufacturer and should include

listening to the recorded signals on each channel to verify that the audio is

being recorded properly, is intelligible, and is free from electrical noise or

other interference. The periodic maintenance check of the CVR should

include an audio test followed by a download and review of each channel

of recorded audio. The downloaded recording should be checked for

overall audio quality, CVR functionality, and intelligibility. (A-06-23)
Recommendations 61 Aircraft Accident Report

4.2 Additional Recommendations Resulting From This 

Accident Investigation

As a result of the investigation of this accident (and the August 2005 accident

involving the S-76C helicopter that crashed in the Baltic Sea shortly after takeoff),123 the

Safety Board issued the following recommendations to the FAA on March 7, 2006:

Require all rotorcraft operating under 14 Code of Federal Regulations

Parts 91 and 135 with a transport-category certification to be equipped with

a cockpit voice recorder (CVR) and a flight data recorder (FDR). For those

transport-category rotorcraft manufactured before October 11, 1991,

require a CVR and an FDR or an onboard cockpit image recorder with the

capability of recording cockpit audio, crew communications, and aircraft

parametric data. (A-06-17)

Do not permit exemptions or exceptions to the flight recorder regulations

that allow transport-category rotorcraft to operate without flight recorders,

and withdraw the current exemptions and exceptions that allow

transport-category rotorcraft to operate without flight recorders. (A-06-18)

4.3 Previously Issued Recommendation Classified in 

This Report

Safety Recommendation A-02-25 (previously classified ìOpenóAcceptable

Responseî) is classified ìClosedóSupersededî as a result of the issuance of Safety

Recommendation A-06-23.

123 See sections 1.16.2 and 2.6 for more information about this accident.

BY THE NATIONAL TRANSPORTATION SAFETY BOARD

MARK V. ROSENKER

Acting Chairman

ELLEN ENGLEMAN CONNERS

Member

DEBORAH A. P. HERSMAN

Member

KATHRYN O. HIGGINS

Member

Adopted: March 7, 2006

63 Aircraft Accident Report

5. Appendixes

Appendix A

Investigation and Public Hearing

Investigation

The National Transportation Safety Boardís South Central Regional Office in

Arlington, Texas, was initially notified of this accident. Investigators from Safety Board

headquarters in Washington, D.C., arrived at LCH on March 25, 2004. A Board

investigator participated in recovery operations in the Gulf of Mexico. Wreckage

identification and documentation occurred at LCH. Investigators remained on scene until

April 3, 2004.

Four investigative teams were formed: operations, airworthiness, human

performance, and cockpit voice recorder. Specialists in the areas of air traffic control,

survival factors, and meteorology assisted in the investigation.

Parties to the investigation were the FAA; Era Aviation, LLC; Union Oil Company

of California; Sikorsky Aircraft Corporation; and Honeywell. In accordance with the

provisions of Annex 13 to the Convention on International Civil Aviation, the Safety

Boardís counterpart agency in France, the Bureau díEnquÍtes et díAnalyses pour la

SÈcuritÈ de líAviation Civile (BEA) participated in the investigation as the representative

of the State of Design and Manufacture (Powerplants). Turbomeca participated in the

investigation as a technical advisor to the BEA, as provided in Annex 13.

Public Hearing

No public hearing was held for this accident.
64 Aircraft Accident Report

Appendix B

Cockpit Voice Recorder 

The following is the transcript of the L-3 Communications FA2100 cockpit voice

recorder, serial number 118739, installed on an Era Aviation Sikorsky S-76A++,

N579EH, which crashed into the Gulf of Mexico during controlled flight on March 23,

2004.

$-$23

456  



6456 



7

777 

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:;#

111  ""

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(*' +

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.

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0"


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/
(("
-


+'(*' 65$5362$266..$2%23&,&6$6352- &62&54 4--
"(""
(%23&,"%5%2&%	1"")

+7%22&%2645689/88%22&:645689/--888%25&6456888--+0"+;"-<=8--->888%2?&,645689/888>/88"-<=---888%2?%&?6456888-<=---
888%5%,&?456="-"88>@"" A0 888%5%&64569/-->8--8- "0>888>88-

+8->8"-+++)+'(*' 65$5362$266..$2%5%2&%	4"
--

"
7%5%2&,?4"

/"7%5%2&		+	4"1:<BC"
0+
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/1

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/1

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,	7%5%2&		+2$2362&54 $236$6352-
67 Aircraft Accident Report

Appendix C

Flight Simulation Scenarios 

The Safety Board examined numerous possible scenarios in which the flight

crewís actions could have inadvertently led to a controlled descent into water. The Board

used FlightSafetyís S-76A simulator for these tests. All of the scenarios were based on a

flight that occurred at night and over water with limited visual references (sparse lighting

from platforms) and a cloud ceiling of 2,000 feet agl. For each of the scenarios, the

starting altitude was 1,100 feet msl, the airspeed was 130 knots, the autopilots were

engaged in the ATT mode, the initial rate of descent was 200 fpm, and the decision height

was 200 feet. All of the scenarios involved a change in heading of 10o to the right (to

reflect the flight crewís decision not to refuel at High Island A-557 and to proceed directly

to the Discoverer Spirit) and a resulting increase in rate of descent from 200 fpm to 250 to

300 fpm, which was maintained after the helicopter rolled to a level altitude.

The four scenarios that were deemed to be the most likely to have occurred during

the accident flight (assuming that the flight crew had engaged the DDAFCS) were (1)

pilot 2 maintained control but did not select altitude hold mode, (2) pilot 1 coupled the

flight director but did not select altitude hold mode, (3) pilot 1 selected the altitude mode

but did not couple the flight director, and (4) pilot 1 selected the altitude preselect mode but

did not couple the flight director. A detailed description of each of these scenarios

follows.124

Pilot 2 Maintained Control but Did Not Select Altitude Mode 

The first scenario began with FD2 engaged and coupled and with NAV and VS

selected on the flight director mode selector. Pilot 2 (in the right seat) then pressed SBY

on the flight director mode selector, which canceled the NAV and VS modes and

decoupled FD2. With the HSI heading bug,125 pilot 2 changed the helicopterís heading

10o to the right to reflect the flight crewís decision not to refuel at High Island A-557 and

to proceed directly to the Discoverer Spirit. Pilot 2 then pressed HDG on the flight

director mode selector, coupling FD2 once again, but did not press ALT. Because the

helicopterís power setting was not changed and ALT was not selected on pilot 2ís flight

director mode selector, the process of making the 10o turn to the right led to a 250- to

300-fpm descent that was maintained after rollout.

124 The abbreviations discussed in these four scenarios are defined in section 1.6.3.2.

125 The heading bug is a blue notch that is positioned around a rotating compass card to indicate the

direction in which the helicopter is to be flown.
Appendix C 68 Aircraft Accident Report

The following is a description of what was seen on pilot 2ís instrumentation during

this scenario:

ï A green HDG indication appeared at the top left of the ADI after the pilot

pressed the HDG button on the flight director mode selector.

ï No command bars appeared initially on the ADI because FD2 was

automatically set to SBY before HDG was selected. Once the selection was

made, the command bars appeared. The pitch command bar was centered, and

the roll command bar was in the neutral position.

ï The radar altitude appeared in blue at the bottom right of the ADI followed by

an RA indication in white. 

ï The decision height was displayed in blue at the bottom left of the ADI

followed by a DH indication in white. A white square box appeared above the

radar altitude (at the bottom right of the ADI) when the helicopter was 100 feet

above the decision height (based on the radar altimeter). When the decision

height was reached, an amber DH indication appeared inside the box and

remained there as the helicopter continued to descend. 

ï A yellow rising runway symbol appeared at the bottom center of the ADI at

180 feet (based on the radar altimeter). As the helicopterís altitude decreased,

this symbol ascended until it met the aircraft symbol at 0 feet.

ï The flight director mode selectorís SBY button was initially illuminated in

green. Once the HDG button was selected, it illuminated in green, and the SBY

button was no longer illuminated.

ï The VSI showed a rate of descent of 250 to 300 fpm, which placed the needle

below the centerline.

ï The barometric altimeter showed decreasing altitude by a counterclockwise

rotation of the needle.

Pilot 1 Coupled the Flight Director but Did Not Select Altitude Mode 

The second scenario began with FD2 engaged and coupled and with NAV and VS

selected on the flight director mode selector. Pilot 2 (in the right seat) transferred control

of the helicopter to pilot 1 (in the left seat). Pilot 1 then selected FD1, and the flight

director mode selector was automatically set to SBY. With the HSI heading bug, pilot 1

changed the helicopterís heading 10o to the right. Pilot 1 then pressed HDG on the flight

director mode selector, coupling FD1, but did not press the ALT button. Because the

power setting was not changed and ALT was not selected on pilot 1ís flight director

selector mode, the process of making the 10o turn to the right led to a 250- to 300-fpm

descent that was maintained after rollout. 
Appendix C 69 Aircraft Accident Report

 The following is a description of what was seen on pilot 1ís instrumentation

during this scenario:

ï A green CPLT FD indication appeared at the top left of the caution/advisory

panel. 

ï A green HDG indication appeared at the top left of the ADI after the HDG

button on the flight director mode selector was pressed.

ï The command bars disappeared from the ADI when FD1 was selected. When

HDG was selected, the command bars reappeared. The pitch command bar

was centered, and the roll command bar was in the neutral position.

ï The radar altitude appeared in blue at the bottom right of the ADI followed by

an RA indication in white.

ï The decision height was displayed in blue at the bottom left of the ADI

followed by a DH indication in white. A white square box appeared above the

radar altitude (at the bottom right of the ADI) when the helicopter was 100 feet

above the decision height (based on the radar altimeter). When the decision

height was reached, an amber DH indication appeared inside the box and

remained there as the helicopter continued to descend.

ï A yellow rising runway symbol appeared at the bottom center of the ADI at

180 feet (based on the radar altimeter). As the helicopterís altitude decreased,

this symbol ascended until it met the aircraft symbol at 0 feet.

ï The flight director mode selectorís SBY button was initially illuminated in

green. Once the HDG button was selected, it illuminated in green, and the

SBY button was no longer illuminated.

ï The VSI showed a rate of descent of 250 to 300 fpm, which placed the needle

below the centerline.

ï The barometric altimeter showed decreasing altitude by a counterclockwise

rotation of the needle.

Pilot 1 Selected Altitude Mode but Did Not Couple the Flight Director

The third scenario began with FD2 engaged and coupled and with NAV and VS

selected on the flight director mode selector. Pilot 2 (in the right seat) transferred control

of the helicopter to pilot 1 (in the left seat). Pilot 1 selected FD1 and then selected CPL on

the autopilot controller, which decoupled FD1. With the HSI heading bug, pilot 1

changed the helicopterís heading 10o to the right. Pilot 1 also pressed HDG and then ALT

on the flight director mode selector. Because the power setting was not altered and FD1

was not coupled, the heading change led to a 250- to 300-fpm descent that was maintained

after rollout.
Appendix C 70 Aircraft Accident Report

The following is a description of what was seen on pilot 1ís instrumentation during

this scenario:

ï A green CPLT FD indication appeared at the top left of the caution/advisory

panel, even after FD1 was decoupled. 

ï After the HDG and ALT buttons on the flight director mode selector were

pressed, green HDG and ALT indications appeared at the top left and top right,

respectively, of the ADI. 

ï The command bars disappeared from the ADI when FD1 was selected. When

HDG was selected, the command bars reappeared. The pitch command bar

appeared above the center position, and the roll command bar was in the

neutral position.

ï The radar altitude appeared in blue at the bottom right of the ADI followed by

an RA indication in white. 

ï The decision height was displayed in blue at the bottom left of the ADI

followed by a DH indication in white. A white square box appeared above the

radar altitude (at the bottom right of the ADI) when the helicopter was 100 feet

above the decision height (based on the radar altimeter). When the decision

height was reached, an amber DH indication appeared inside the box and

remained there as the helicopter continued to descend.

ï A yellow rising runway symbol appeared at the bottom center of the ADI at

180 feet (based on the radar altimeter). As the helicopterís altitude decreased,

this symbol ascended until it met the aircraft symbol at 0 feet.

ï The flight director mode selectorís SBY button was initially illuminated in

green. Once the HDG and ALT buttons were selected, they illuminated in

green, and the SBY button was no longer illuminated.

ï The VSI showed a rate of descent of 250 to 300 fpm, which placed the needle

below the centerline.

ï The barometric altimeter showed decreasing altitude by a counterclockwise

rotation of the needle.

Pilot 1 Selected Altitude Preselect but Did Not Couple the Flight Director

The fourth scenario began with FD2 engaged and coupled and with NAV and VS

selected on the flight director mode selector. Pilot 2 (in the right seat) transferred control

of the helicopter to pilot 1 (in the left seat). Pilot 1 selected FD1 and then CPL on the

autopilot controller, which decoupled FD1. With the heading bug, pilot 1 changed the

helicopterís heading 10o to the right. Pilot 1 pressed HDG and ALT PRE on the flight

director mode selector and entered the desired altitude (900 feet) into the AL-300. Pilot 1

also pressed VS on the flight director mode selector and entered the desired rate of descent

(200 fpm) with the collective. The helicopter descended at that rate until reaching the

selected altitude. However, because the power setting was not altered and FD1 was not

coupled, the heading change led to a 250- to 300-fpm descent that was maintained after

rollout.
Appendix C 71 Aircraft Accident Report

The following is a description of what was seen on pilot 1ís instrumentation during

this scenario:

ï A green CPLT FD indication appeared at the top left of the caution/advisory

panel, even after FD1 was decoupled. 

ï After the HDG and ALT PRE buttons on the flight director mode selector were

selected, a green HDG indication appeared at the top left of the ADI, and a

white ALTP (altitude preselect) indication surrounded by a white box appeared

at the top right of the ADI. The white ALTP indication changed to a green

ALT indication after the selected altitude was reached.

ï After the VS button on the flight director mode selector was selected, a green

VS indication appeared on the left side of the ADI. The green VS indication

disappeared after the selected altitude was reached.

ï The command bars disappeared from the ADI when FD1 was selected. When

HDG was selected, the command bars reappeared. The pitch command bar

was centered, and the roll command bar was in the neutral position.

ï The radar altitude appeared in blue at the bottom right of the ADI followed by

an RA indication in white.

ï The decision height was displayed in blue at the bottom left of the ADI

followed by a DH indication in white. A white square box appeared above the

radar altitude information when the helicopter was 100 feet above the decision

height (based on the radar altimeter). When the decision height was reached,

an amber DH indication appeared inside the box and remained there as the

helicopter continued to descend.

ï A yellow rising runway symbol appeared at the bottom center of the ADI at

180 feet (based on the radar altimeter). As the altitude decreased, this symbol

ascended until it met the aircraft symbol at 0 feet.

ï The flight director mode selectorís SBY button was initially illuminated in

green. Once the HDG button was selected, it illuminated in green, and the

SBY button was no longer illuminated. Also, the flight director mode

selectorís VS button illuminated in green and the ALT PRE buttonís ARM

light illuminated in amber to indicate that the helicopter was descending

toward the preselected altitude. When the helicopter was near the preselected

altitude, the ALT PRE buttonís ARM light extinguished, and the CAP

(captured) light illuminated in green. Once the helicopter reached the selected

altitude, the CAP light extinguished, and the green ALT button illuminated.

ï The VSI showed a rate of descent of 250 to 300 fpm, which placed the needle

below the centerline.

ï The barometric altimeter showed decreasing altitude by a counterclockwise

rotation of the needle. 
Appendix C 72 Aircraft Accident Report

ï At an altitude of 600 feet (300 feet below the preselected altitude), an amber

light at the top left of the barometric altimeter illuminated, and an aural tone

sounded over the pilotsí headsets for 1 second. The light remained illuminated

throughout the rest of the flight. 
73 Aircraft Accident Report

Appendix D

Gulf of Mexico Helicopter Accident Data

March 2000 Through February 2006

The following is a list of Gulf of Mexico helicopter accidents from 2000 to

February 2006:

Date Operator Model

Number of injuries

Fatal Serious Minor None

Part 135 operations

 3-20-00 Horizon Helicopters Bell 206 3

 5-24-00 Tex-Air Helicopters Eurocopter AS-350 2

 5-31-00 Panther Helicopters Bell 206 1

12-26-00 Tarlton Helicopters Bell 206 1

 3-20-01 Air Logistics Sikorsky S-76A 1 8

 5-4-01 Air Logistics Bell 407 2

 8-5-01 Air Logistics Bell 206 3

 8-24-01 Air Logistics Bell 206 2

 9-26-01 Air Logistics Bell 206 3

10-18-01 Air Logistics Bell 206 3 2

 7-25-02 Air Logistics Bell 206 2

 8-1-02 Go Helitrans Bell 206 4

 1-9-03 Tex-Air Helicopters Aerospatiale AS-350 4 1

 1-16-03 Air Logistics Bell 206 1 3

 1-21-03 Air Logistics Bell 206 5

 2-16-03 Houston Helicopters Bell 407 2 3

 2-22-03 Petroleum Helicopters Bell 407 1 1

 3-24-03 Petroleum Helicopters Bell 407 2

 5-11-03 Petroleum Helicopters Bell 407 4

 5-29-03 Tarlton Helicopters Robinson R44 1

 7-7-03 Tex-Air Helicopters Aerospatiale AS-350 2

 8-13-03 Petroleum Helicopters Bell 206 3 1 1

 9-12-03 Go Helitrans Bell 206 1 3

10-10-03 Petroleum Helicopters Bell 206 3

 12-1-03 Petroleum Helicopters Bell 407 1

 1-28-04 Rotocraft Leasing 

Company

Bell 206 6

 3-6-04 Petroleum Helicopters Bell 206 1 2

 3-23-04 Era Aviation Sikorsky S-76A 10

 6-24-04 American Helicopters Bell 206 3

 7-21-04 Omni Energy Services Bell 206 1 2

 9-29-04 Panther Helicopters Bell 206 3

 11-5-04 Rotocraft Leasing 

Company

Bell 206 1 1 1

12-17-04 Omni Energy Services Bell 407 1 1 2

 2-18-05 Rotocraft Leasing 

Company

Bell 206 3
Appendix D 74 Aircraft Accident Report

Date Operator Model

Number of injuries

Fatal Serious Minor None

Part 91 operations

 6-8-05 American Helicopters Bell 206 4

 7-11-05 Chevron/Texaco USA Bell 430 3

 9-6-05 Houston Helicopters Sikorsky S-76A 4 6

 10-6-05 Industrial Helicopters Bell 206 3

 4-29-00 Chevron USA Bell 206 2

 9-7-00 Horizon Helicopters Bell 206 1

10-28-00 Tex-Air Helicopters Aerospatiale AS-350 1

 12-1-00 American Helicopters Bell 206 1

12-29-00 Petroleum Helicopters Bell 407 1

 7-10-01 Air Logistics Sikorsky S-76A 1

11-10-01 Industrial Helicopters Bell 407 1

 1-8-02 Air Logistics Bell 206 1

 3-23-02 Petroleum Helicopters Bell 206 1

 6-29-02 Evergreen Helicopters Bell 206 1

12-31-02 Air Logistics Bell 206 1

 3-6-03 Taylor Energy Company Eurocopter AS-350 5

 7-8-03 Tex-Air Helicopters Eurocopter EC120 3

 7-17-04 Rotocraft Leasing 

Company

Bell 206 1

 12-9-04 Evergreen Helicopters Bell 206 1

 3-13-05 Rotorcraft Leasing 

Company

Bell 206 1

 8-17-05 Air Logistics Bell 206 1

 8-18-05 Air Logistics Bell 206 2

 2-19-06 Central Helicopters Bell 222 2