PB96-910403

NTSB/AAR-96/03 .

I

NATIONAL

TRANSPORTATION

SAFETY

BOARD

WASHINGTON, D.C. 20594

I

AIRCRAFT ACCIDENT REPORT

UNCONTAINED ENGINE FAILURE/FIRE

VALUJET AIRLINES FLIGHT 597

DOUGLAS DC-9-32, N908VJ

ATLANTA, GEORGIA

JUNE 8, 1995

I

I

6579A

I
The National Transportation Safety Board is an independent Federal agency dedicated to

promoting aviation, railroad, highway, marine, pipeline, and hazardous materials safety.

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Board Act of 1974 to investigate transportation accidents, determine the probable causes of

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(202)382-6735

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(703)487-4600
NTSB/AAR-96/03 PB96-910403

NATIONAL TRANSPORTATION

SAFETY BOARD

WASHINGTON, D.C. 20594

AIRCRAFT ACCIDENT REPORT

UNCONTAINED ENGINE FAILURE/FIRE

VALUJET AIRLINES FLIGHT 597

DOUGLAS DC-9-32, N908VJ

ATLANTA, GEORGIA

JUNE 8,1995

Adopted: July 30, 1996

Notation 6579A

Abstract: This report explains the uncontained engine failure/fire on ValuJet Airlines flight 597, a

Douglas DC-9-32, N908VJ, at Atlanta, Georgia, on June 8, 1995. The safety issues discussed in the

report include the clarity of operations specifications for repair stations, recordkeeping requirements

for foreign repair stations, regulatory guidance concerning maintenance documentation, intent of

“serviceable tags,” independently powered public address systems on all transport-category

airplanes, flight attendant training programs and manuals, enforcement of occupant restraint

requirements, notification of flightcrew of cabin fire, cabin material/fire safety standards, flight

attendant attire, and quality of cockpit voice recordings. Safety recommendations concerning these

issues were made to the Federal Aviation Administration (FAA).

iii

CONTENTS

EXECUTIVE SUMMARY............................................................................................................ vi

1. FACTUAL INFORMATION..................................................................................................... 1

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

1.2 Injuries to Persons ................................................................................................................. 3

1.3 Damage to Aircraft................................................................................................................ 3

1.4 Other Damage........................................................................................................................ 3

1.5 Personnel Information ........................................................................................................... 3

1.5.1 The Captain .................................................................................................................... 3

1.5.2 The First Officer............................................................................................................. 4

1.5.3 Flight Attendants............................................................................................................ 4

1.6 Aircraft Information .............................................................................................................. 4

1.6.1 Aircraft Origin and Configuration.................................................................................. 4

1.6.2 Emergency Lighting and Power ..................................................................................... 5

1.7 Meteorological Information .................................................................................................. 7

1.8 Aids to Navigation ................................................................................................................ 7

1.9 Communications ................................................................................................................... 7

1.10 Airport Information ............................................................................................................. 8

1.11 Flight Recorders .................................................................................................................. 8

1.12 Wreckage and Impact Information...................................................................................... 9

1.12.1 Right Engine................................................................................................................. 9

1.12.2 Left Engine................................................................................................................. 11

1.12.3 Fuselage...................................................................................................................... 11

1.13 Medical and Pathological Information .............................................................................. 12
iv

1.14 Fire .................................................................................................................................... 14

1.14.1 Emergency Response.................................................................................................. 14

1.15 Survival Aspects................................................................................................................ 14

1.16 Tests and Research ............................................................................................................ 16

1.16.1 Metallurgical Examinations ....................................................................................... 16

1.16.2 Burn Tests of Cabin Furnishings................................................................................ 20

1.17 Additional Information...................................................................................................... 21

1.17.1 ValuJet’s Purchase of Turk Hava Yollari (THY) Aircraft, Engines, and Spare Parts 21

1.17.1.1 Pre-delivery Activities in Turkey ............................................................................ 21

1.17.1.2 Post-delivery Activities in the United States........................................................... 25

1.17.2 1991 Overhaul/Inspection of 7th Stage HPC Disk by THY........................................ 26

1.17.3 Pratt & Whitney Guidance on Engine Overhaul/Inspection ...................................... 28

1.17.4 FAA Regulations Regarding the Return to Service of the Spare Engines ................. 30

1.17.5 THY Repair Station.................................................................................................... 32

1.17.5.1 Pratt & Whitney Engine Shop Maintenance Review .............................................. 34

1.17.5.2 FAA Inspections of THY Repair Station ................................................................ 35

1.17.6 ValuJet’s Flight Attendant Training Program............................................................ 37

1.17.7 Safety Board Recommendations Subsequent to the Accident ................................... 38

2. ANALYSIS .............................................................................................................................. 41

2.1 General ................................................................................................................................ 41

2.2 Uncontained Engine Failure................................................................................................ 41

2.3 Overhaul Procedures by THY ............................................................................................. 42

2.4 Adequacy of FAA Recordkeeping Requirements. .............................................................. 45
v

2.5 Maintenance Release and “Serviceable” Tags for Aircraft Components............................ 47

2.6 THY’s Authority to Overhaul JT8D Engines...................................................................... 47

2.7 Emergency Lighting and Public Address System ............................................................... 48

2.8 ValuJet’s Flight Attendant Training Program..................................................................... 50

2.9 In-Lap Children over 2 Years Old....................................................................................... 51

2.10 Notification of Flightcrew of Cabin Fire........................................................................... 52

2.11 Fire Retardant Cabin Furnishings...................................................................................... 53

2.12 ValuJet Flight Attendant Uniforms................................................................................... 55

2.13 Quality of CVR Recording................................................................................................ 55

3. CONCLUSIONS...................................................................................................................... 57

3.1 Findings............................................................................................................................... 57

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

4. RECOMMENDATIONS ......................................................................................................... 60

5. APPENDIXES ......................................................................................................................... 63

APPENDIX A - Investigation And Hearing.................................................................................. 63

APPENDIX B - CVR Transcript................................................................................................... 65

APPENDIX C - Example of a “Process Sheet” ............................................................................ 91

APPENDIX D - Pratt &Whitney Plating Requirements for #7 HPC Disk ................................. 102

APPENDIX E - Examples of THY Repair Station Operations Specifications........................... 118

APPENDIX F - Examples of ValuJet’s Flight Attendant Manual Emergency Equipment—Before

and After Revision in November 11, 1995 ................................................................................. 126

APPENDIX G - Comparison of Requirements for Domestic and Foreign Repair Stations

Certificated Under FAR Part 145................................................................................................ 128
vi

EXECUTIVE SUMMARY

On June 8, 1995, a Douglas DC-9-32, N908VJ, was being operated by ValuJet

Airlines as a scheduled, domestic passenger flight under the provisions of Title 14 Code of

Federal Regulations (CFR) Part 121. Flight 597, destined for Miami, Florida, departed gate C25

at the William B. Hartsfield Atlanta International Airport, Atlanta, Georgia, at 1855, and was

cleared for takeoff on runway 27R at 1908. Five crewmembers and 57 passengers were on

board.

As flight 597 began its takeoff roll, a "loud bang" was heard by the airplane occupants

and air traffic control personnel. The right engine fire warning light illuminated, the flightcrew

of a following airplane reported to the ValuJet crew that the right engine was on fire, and the

takeoff was rejected. Shrapnel from the right engine penetrated the fuselage and the right engine

main fuel line, and a cabin fire erupted. The airplane was stopped on the runway, and the captain

ordered the evacuation of the airplane.

The flight attendant seated in the aft flight attendant jumpseat received serious

puncture wounds from shrapnel and thermal injuries. Another flight attendant and five

passengers received minor injuries. The pilots, the third flight attendant, and 52 passengers were

not injured. The airplane’s fuselage was destroyed.

The National Transportation Safety Board determines that the probable cause of this

accident was the failure of Turk Hava Yollari maintenance and inspection personnel to perform a

proper inspection of a 7th stage high compressor disk, thus allowing the detectable crack to grow

to a length at which the disk ruptured, under normal operating conditions, propelling engine

fragments into the fuselage; the fragments severed the right engine main fuel line, which resulted

in a fire that rapidly engulfed the cabin area. The lack of an adequate recordkeeping system and

the failure to use “process sheets” to document the step-by-step overhaul/inspection procedures

contributed to the failure to detect the crack and, thus, to the accident.

The safety issues in this report include the clarity of operations specifications for repair

stations, recordkeeping requirements for foreign repair stations, regulatory guidance concerning

maintenance documentation, intent of “serviceable tags,” independently powered public address

systems on all transport-category airplanes, flight attendant training programs and manuals,

enforcement of occupant restraint requirements, and cabin material/fire safety standards.

Safety recommendations concerning these issues were addressed to the Federal

Aviation Administration.
UNCONTAINED ENGINE FAILURE/FIRE

VALUJET AIRLINES FLIGHT 597

DOUGLAS DC-9-32, N908VJ

ATLANTA, GEORGIA

JUNE 8, 1995

1. FACTUAL INFORMATION

1.1 History of the Flight

On June 8, 1995, a Douglas DC-9-32, N908VJ, was being operated by ValuJet Airlines

as a scheduled, domestic passenger flight under the provisions of Title 14 Code of Federal

Regulations (CFR) Part 121. Flight 597, destined for Miami, Florida, departed gate C25 at the

William B. Hartsfield Atlanta International Airport, Atlanta, Georgia, at 1855,1 and was cleared

for takeoff on runway 27R at 1908. Five crewmembers and 57 passengers were on board.

As flight 597 began its takeoff roll, a "loud bang" was heard by the airplane occupants

and air traffic control personnel. The right engine fire warning light illuminated, the flightcrew of

a following airplane reported to the ValuJet crew that the right engine was on fire, and the takeoff

was rejected. Shrapnel from the right engine penetrated the fuselage and the right engine main

fuel line, and a cabin fire erupted. The airplane was stopped on the runway, and the captain

ordered the evacuation of the airplane.

After the airplane came to a stop, the forward flight attendants opened the forward

passenger boarding door and the service door exits, and the airplane was evacuated. The flight

attendant at the service door exit stated that when the door was opened, the cabin filled with

smoke from about waist level up to the ceiling.

The flight attendant seated in the aft flight attendant jumpseat received serious puncture

wounds from shrapnel and thermal injuries and evacuated herself from the airplane through an

overwing exit. Another flight attendant and five passengers received minor injuries. The pilots,

the third flight attendant, and 52 passengers were not injured. The airplane’s fuselage was

destroyed.

The accident occurred at dusk. The airplane came to a stop about 1,500 feet down

runway 27R, before taxiway M18, approximately 33° 38’04” North latitude and 84° 24’50” West

longitude (see figure 1).

 

1

 Unless otherwise indicated, all times are eastern standard time, based on a 24-hour clock.
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Figure l—Location of flight 597 at Hartsfield Atlanta
3

1.2 Injuries to Persons

Injuries

Cockpit

crew

Flight

attendants Passengers Other Total

Fatal 0 0 0 0 0

Serious 0 1 0 0 1

Minor 0 1 5 0 6

None 2 1 52 0 55

Total 2 3 57 0 62

1.3 Damage to Aircraft

The fuselage was destroyed by fire, which gutted the interior, burned through the roof of

the forward cabin area of the airplane, and consumed most of the cabin overhead. There was

substantial exterior damage with circumferential outward tearing of the right engine cowl and

engine case in the plane of rotation of the right engine 7th stage high pressure compressor (HPC)

disk. There was also shrapnel damage to the fuselage and left engine cowl.

1.4 Other Damage

No other property damage resulted from this accident.

1.5 Personnel Information

The flightcrew consisted of the captain and the first officer. Three flight attendants

were aboard the airplane.

1.5.1 The Captain

The captain, age 45, was hired by ValuJet Airlines on November 25, 1993, as a captain

on DC-9 airplanes. He held an airline transport pilot (ATP) certificate, with an airplane

multiengine land rating, and DC-9, Boeing 737, and Lear Jet type ratings. He had commercial

pilot privileges for airplane single-engine land. He was a certified flight instructor with airplane

multiengine and instrument airplane ratings.

The captain’s first-class medical certificate was issued on March 21, 1995, with no

restrictions or limitations.

The captain was a designated pilot examiner for Boeing 737 airplane type ratings. His

last proficiency check was completed on May 7, 1995, in the DC-9 airplane. According to

company records, the captain had accumulated about 9,500 total flight hours, with about 3,500

hours in the DC-9, and 2,500 hours as a DC-9 captain. The captain had about 11 years previous

experience with Eastern Airlines as a DC-9 captain and first officer, a Boeing 727 first officer, and

a Lockheed L-1011 second officer.
4

The captain reported for duty on the day of the accident at 1332, following 3 days off

duty.

1.5.2 The First Officer

The first officer, age 43, was hired by ValuJet Airlines on October 28, 1994, as a first

officer on the DC-9 airplane. He held an ATP certificate with airplane single-engine and

multiengine land ratings.

His first-class medical certificate was issued on September 14, 1994, with no

restrictions or limitations. The first officer’s last proficiency check was completed on May 29,

1995, in the DC-9 airplane. According to company records, he had accumulated about 3,800 total

flight hours with 552 hours in the DC-9, all as first officer. The first officer had previous flight

experience in a Lockheed P-32 with the United States Navy, between 1982 and 1991.

The first officer reported for duty on the day of the accident at 1328, following 2 days

off duty.

1.5.3 Flight Attendants

Two flight attendants occupied the aft-facing double-occupancy jumpseat in the forward

cabin at the time of the accident. One of the flight attendants had completed her initial ValuJet

training on November 15, 1994. She had been previously employed as a flight attendant with

Eastern Airlines for 71⁄2 years and with Private Jet for 11⁄2 years. She was scheduled for her first

recurrent training in November 1995.

The other flight attendant in the forward section of the cabin had completed her initial

training on December 15, 1994. She had no prior flight attendant experience. She was scheduled

for her first recurrent training in December 1995.

The flight attendant who occupied the jumpseat in the rear cabin had completed her

initial training on December 23, 1993. She had no prior flight attendant experience. Her most

recent recurrent training before the accident was completed in November 1994.

1.6 Aircraft Information

1.6.1 Aircraft Origin and Configuration

N908VJ, a Douglas DC-9-32, serial number (SN) 47321, was registered to ValuJet

Airlines. The airplane was purchased from the Douglas Aircraft Company and was put into

service as part of ValuJet’s fleet on February 4, 1994. It had previously been operated by Delta Air

Lines. The airplane was powered by two Pratt & Whitney (P&W) JT8D-9A turbofan engines.

 

2

 The Lockheed P-3 is a Navy antisubmarine patrol plane equipped with four turbopropeller engines.
5

The right engine, SN 666966, was installed on the airplane in March 1995. It had been obtained

by ValuJet from Turk Hava Yollari (THY) A.O., Turkish Airlines, in a large equipment purchase

on October 3, 1994, that included a total of 23 engines.3 THY is a Turkish domestic and

international airline that also operates an airframe and engine repair station.

At the time of the accident, flight 597 had a basic operating weight of 61,564 pounds

and a takeoff weight of 96,374 pounds; maximum takeoff weight for this DC-9-32 was 102,900

pounds. The center of gravity was at 23 percent mean aerodynamic chord, which was within

limits. During the pre-departure preparations, the flightcrew noted that the traffic collision and

avoidance system (TCAS) fail light remained illuminated. The minimum equipment list for the

accident aircraft indicated that the TCAS was not required for flight, and at the time of the

accident, this discrepancy could be left uncorrected for up to 10 days.

The airplane was configured with 108 passenger seats. Supplemental oxygen for both

the flightcrew and the passengers was provided by compressed oxygen-filled bottles.

Two floor-level exits were located in the forward cabin, four overwing exits were

located at rows 14 and 16, and a tailcone exit was located at the rear of the cabin. (See figure 2.)

Two cockpit windows could be used as emergency exits.

1.6.2 Emergency Lighting and Power

The airplane was equipped with a cabin floor path emergency lighting system, which,

along with other emergency lights, provides illumination in the main cabin when the normal

electrical power is interrupted. The emergency lighting system was installed in accordance with a

supplemental type certificate.4 The emergency lighting system is powered by either the

Emergency direct current (DC) Bus or dedicated rechargeable battery packs and is controlled by a

three-position emergency lighting switch with positions “ON,” “OFF,” and “ARMED” located in

the cockpit overhead panel. The Emergency DC Bus is normally powered by engine-driven

generators. It can also be activated by manually selecting emergency electrical power. Placing the

emergency lighting switch to “ON” illuminates the emergency lights when the Emergency DC Bus

is powered. The “ARMED” position is the normal flight position, which turns off the emergency

lights and causes the battery packs to be charged. The “OFF” position extinguishes the lights and

discontinues the charging of the batteries.

If electrical power to the Emergency DC Bus is interrupted, the emergency lights

automatically illuminate (if the emergency lighting switch is in the “ARMED” position), with the

electrical power provided by the battery packs. The manual selection of emergency electrical

 

3

 See section 1.17.1 discussed later in this report.

4

 An emergency floor path proximity lighting system was not required when the DC-9 was introduced into service.

Subsequently, Federal regulations required transport-category airplanes in commercial passenger service to be so

equipped. Therefore, emergency lighting systems were installed in accordance with supplemental type certificates that

were approved by the Federal Aviation Administration (FAA).
u

=7

Figure 2—DC9-32 cabin configuration
7

power restores power to the Emergency DC Bus from the aircraft’s batteries; however, unless the

emergency light switch is first moved from the “ARMED” to the “ON” position, this action will

also extinguish the emergency lights and resume charging of the battery packs. Placing the cabin

emergency lighting switch to the “ON” position was the fourth item on the ValuJet Emergency

Evacuation Checklist.5

The airplane was equipped with a public address (PA) system that enabled the

flightcrew and flight attendants to address occupants through loudspeakers located throughout the

cabin. The PA system is also powered by the Emergency DC Bus. An interruption of electrical

power to the Emergency DC Bus disables the PA system. Manual selection of emergency

electrical power restores power to the PA system.

1.7 Meteorological Information

Visual meteorological conditions prevailed at the time of the accident.

The Hartsfield Atlanta International Airport hourly weather observation at 1850 was:

sky—scattered clouds, ceiling at 5,500 feet; visibility—12 miles; temperature—93 °F; dew

point—71 °F; wind—290° at 8 knots; and altimeter setting—29.99. The weather was essentially

the same at the next hourly observation.

1.8 Aids to Navigation

There were no known difficulties with aids to navigation.

1.9 Communications

There were no known external communication difficulties involving the airplane. The

flightcrew of Delta flight 846, which had been cleared to “position and hold” behind flight 597,

advised the ValuJet crew of a fire in the right engine, prompting the captain to reject the takeoff

and stop the airplane on the runway.

After the captain stopped the airplane and the engines were shut down, he attempted to

communicate to the passengers using the PA system but was unable to do so. After the captain

selected emergency electrical power, the power was restored to the PA system, and the captain

successfully communicated the evacuation order.

One of the flight attendants in the forward section of the cabin saw flames around the

flight attendant in the aft jumpseat and tried to notify the flightcrew of the fire by opening the

cockpit door. As required by FAA regulations, the cockpit door was locked. While one of the

forward flight attendants reached for the cockpit door key, which had been stored in the galley per

 

5

 The first three items on the checklist are (1) setting the parking brakes, (2) retracting the spoilers, and

(3) lowering the flap handle.
8

ValuJet procedures, the other flight attendant successfully opened the cockpit door with her own

key and informed the flightcrew of the fire. The captain then ordered an evacuation through the

forward exits.

According to ValuJet’s flight attendant manual in effect at the time of the accident:

If life threatening conditions exist inside the cabin, the first crewmember

aware of the situation shall notify the pilots via the interphone using the

emergency signal (six chimes).6 If no response, unlock the cockpit door and

evaluate conditions. If able, the captain will evaluate the situation and, if

necessary, initiate an evacuation with the PA announcement of Evacuate,

Evacuate, Evacuate.

The flight attendant manual further provides that “If a life threatening situation exists

inside the cabin, and you are unable to contact the cockpit, begin shouting the appropriate

commands. Once the aircraft comes to a complete stop, initiate the evacuation. Note: An

evacuation should not be initiated until the aircraft has come to a complete stop.”

1.10 Airport Information

The William B. Hartsfield Atlanta International Airport is located 6 miles south of

Atlanta, Georgia. It is served by four parallel runways oriented east/west. The terminal building

and passenger loading concourses are situated between the two innermost parallel runways.

Runway 27R, used by ValuJet flight 597, is the runway closest to the terminal on the south side of

the terminal/concourse area. Departure operations are normally conducted from the inner

runways, with landing operations normally conducted on the outer runways. Runway 27R is

11,889 feet long and 150 feet wide. The approach threshold elevation is 978 feet mean sea level.

Hartsfield International Airport is fully certificated under 14 CFR Part 139 and is an

Index E Aircraft Rescue and Fire Fighting (ARFF) facility.7

1.11 Flight Recorders

Digital flight data (DFDR) and cockpit voice (CVR) recorders were installed in the

airplane. The DFDR was a Fairchild Model F800, SN 05466, with an 11-parameter recorder, with

two channels that were not recording properly. The CVR was a Fairchild Model A-100A, SN

53333. Both recorders were removed from the airplane and sent to the Safety Board’s laboratory

in Washington, D.C., for readout.

 

6

 No chimes were recorded on the CVR. A review of available information, including the CVR transcript and

maintenance records, provided no evidence that the interphone was inoperative.

7

 Title 14 CFR Part 139 requires, for scheduled air carrier service with aircraft at least 200 feet in length, that at a

minimum the airport be equipped with at least three ARFF vehicles with at least 6,000 gallons of water for foam

production.
9

The cases of both recorders were intact and covered with a light sooting. An excellent

recording was obtained from the DFDR, and a recording of fair quality8 was obtained from the

CVR. There was no apparent interior heat or impact damage to the CVR.

Data from the DFDR indicated that the engine pressure ratio (EPR) on both engines

began increasing shortly after flight 597 was cleared for takeoff. The airplane accelerated for

about 14 seconds, reaching an indicated airspeed of about 31 knots when the right engine EPR

decreased from about 1.57 to about 0.91 within 1 second.

The CVR recording consisted of three channels: the cockpit area microphone, the pilot

audio panel, and the interphone/PA system. The cockpit area microphone channel recording

contained background noise that nearly obliterated the pilots’ voices and made them difficult to

understand. A transcript was prepared of the entire 31-minute, 16-second recording. The

transcript of the CVR is contained in appendix B of this report.

The CVR recording started at 1838:03, with the airplane at the gate being prepared for

departure. It continued through the flightcrew’s preparations for departure, taxi, and takeoff. The

recording ended after engine shutdown with the airplane stopped on the departure runway.

1.12 Wreckage and Impact Information

The airplane stopped on the centerline of runway 27R, about 1,500 feet west of the

approach end of the runway. Debris from the right engine was found on the runway, from about

100 feet west of the runway threshold to the stopped airplane. Additional engine debris was found

in the grass areas on either side of the runway. The overwing exit hatch from the right side of

passenger seat row 14 was found on the runway, about 1,200 feet west of the runway threshold.

1.12.1 Right Engine

The right engine, SN 666966, remained attached to the pylon structure. The nacelle

doors were closed, and all four latches were locked. A circumferential tear of the engine nacelle

encompassed the upper and lower nacelle doors from approximately the 9 o’clock position

clockwise to the 6 o’clock position.9

 The circumferential opening was approximately 14 inches

wide and about 67 inches aft of the engine inlet flange. The circumferential tear of the right

engine nacelle was aligned with the rotational plane of the 7th stage HPC disk. The torn edges

 

8

 The Safety Board generally uses the following criteria to assess the quality of a CVR recording: a “poor”

recording is one in which a transcription is nearly impossible given that a large portion of the recording is

unintelligible; a “fair” recording is one in which a transcription is possible, but the recording is difficult to understand;

a “good” recording is one in which few words are unintelligible; and an “excellent” recording is very clear and easily

transcribed.

9

 All clock references to the engine or the airplane are as viewed from aft, looking forward.
10

were ragged and curled outboard, away from the center of the engine. The forward edges of the

hole were burned, with the paint blistered and charred. The nacelle was heat damaged from about

the 1 to 6 o’clock position, to about 15 inches forward of the circumferential opening. The nacelle

lower half was covered with soot aft of the circumferential opening.

The fan discharge outer rear duct and the compressor case were also circumferentially

ripped open through 360° and about 8 inches wide, directly behind the intermediate case (G

flange). A 1-inch-wide strip of fan duct skin remained at the 6 o’clock position.

All of the 1st stage fan blades were in place in the fan disk with varying degrees of hard

body impact damage to the airfoil leading and trailing edges, outboard of the midspan shrouds.

The airfoil trailing edge tips were bent forward.

Only two pieces of the fractured 7th stage HPC disk, SN G78851, were recovered.10

One piece, about half of the disk, was found resting on the accessory gearbox, visible through the

circumferential tear in the cowling. The section of disk, which previously formed the bore for the

missing half of disk, was straight and extended tangentially from the inner diameter of the disk.

The straightened section of disk bore protruded radially out through the circumferential opening in

the compressor case and nacelle at the 5 o’clock position. The 7th stage compressor blades retained

in the disk were bent opposite the direction of rotation.

The 6th stage airseal was separated from the 7th stage disk. The airseal was bent and

fragmented. About 60 percent of the airseal was recovered. The largest fragment, comprising

about 150° of arc, was found lodged in the nacelle, against the pylon. Additional pieces were

recovered from the accident runway and adjacent area.

The 8th stage compressor disk and hub were visible through the circumferential opening

in the fan duct and compressor case. Several 8th stage compressor blades were missing from their

respective blade slots. The remaining blades had hard body damage on the leading edges. All of

the compressor tierods were fractured at the 8th stage disk. Most of the tierod fractured ends

protruded out of the 8th stage disk and were bent radially outward from their respective holes.

The thrust reverser and turbine exhaust case appeared undamaged by the event. The

turbine exhaust case had metal fragments lying on the bottom of the case.

The forward, upper portion of the gearbox case, behind the fuel pump and control

mount pad, was fractured, exposing the internal drive gears. The gearbox mounting lugs were

fractured, and the gearbox was below the running position. The radial driveshaft from the gearbox

to the intermediate case was disengaged. Oil and fuel lines to the gearbox and its associated

accessories were intact. The hydraulic pump housing and main fuel pump separated from their

respective gearbox mount pads.

 

10 A substantial portion of the disk was not recovered.
11

The two pylon vibration absorbers and their respective attachment bolts, aft of “G”

flange, were fractured. The pylon vibration absorbers are in the plane of rotation of the 7th stage

disk.

Thirty-three 7th stage compressor blades were retained in the larger piece of the 7th stage

disk, which was found inside the engine. An arc of 8 and an arc of 11 adjacent blades were bent

opposite the direction of rotation. An arc of 14 blades was transversely fractured, adjacent to the

blade platform.

The smaller piece of the 7th stage disk was recovered from runway 27R, left of the

centerline. The smaller piece of the 7th stage disk had six blades retained in the rim. The blades

were transversely fractured adjacent to the blade platforms.

The two pieces of the 7th stage HPC disk were shipped to the Safety Board’s materials

laboratory in Washington, D.C., for examination. (See section 1.16.1 of this report for details of

the disk examination.)

1.12.2 Left Engine

The left engine (SN 666055) nacelle had a dent and a 1⁄4-inch-diameter puncture at about

the 4 o’clock position in line with a series of holes through the fuselage. Inspection of the engine

inlet, inlet guide vanes, fan, and 4th stage blades did not reveal any damage. There was no fire

damage. The examination of the left engine and data from the DFDR provided no evidence of

problems with the left engine. The left engine was not disassembled or tested.

1.12.3 Fuselage

Several punctures were observed in the fuselage above and below the right engine

pylon. The largest puncture was adjacent to the right engine main fuel line. A 6-inch section of

the fuel line was severed where it passed through the aft lavatory sidewall, about 1 foot above the

cabin floor. The lavatory door had an approximate 1-foot-diameter puncture hole adjacent to the

forward door frame. The galley’s forward frame had a piece of the corner post missing with the

metal smeared to the left side of the airplane. The galley cooler box11 had grooves across its front

side. The left side of the fuselage under the engine pylon had a puncture hole with outward bent

edges, consistent with a projectile penetrating the left side of the fuselage from inside to outside.

A rope was used to establish that the hole in the right side of the fuselage, the hole in the lavatory

door, damage to the galley cooler and frame, the exit hole in the left side of the fuselage, and the

dent in the left engine cowling were all aligned.

Fire damage inside the aft lavatory was less severe than the fire damage elsewhere in the

passenger cabin. The cabin floor support beam at the forward edge of the lavatory, which

 

11 The cooler box, which is a cube-shaped metal container that has an insulated plastic liner, holds canned

beverages in ice cubes. It is located on the forward side of the galley at floor level.
12

extended from sidewall to sidewall, was nearly burned through at the center. The section of cabin

floor surrounding the beam was partially melted and burned. The cargo bay liner beneath the aft

lavatory was charred on the top and sides. Wire bundles and conduits between the cabin floor and

the cargo bay liner in the same area as the damaged floor beam were more severely burned than in

adjacent areas. The injured flight attendant’s jumpseat was immediately aft of the center aisle

section that was nearly burned through. The jumpseat was also just aft of the path made by the

rope used to establish the relationship between the right side fuselage hole and the dent in the left

engine cowling.

The top of the cabin, above the cabin windows, was consumed by fire from the

2nd window rearward to about the 15th window. There was severe interior fire damage to the entire

passenger cabin, with sooting and blackening of the interior of the cockpit. The seat fabric, carpet,

and cabin interior material were nearly consumed by the fire.

The evacuation slides at both forward floor-level exits were found deployed and

inflated. All overwing exit hatches were absent. One overwing exit hatch was found on the

runway along the debris trail. The passenger seated in 14E stated that he opened the right

overwing exit hatch located by his seat and threw it from the airplane. His companion seated in

14C confirmed that account. The passenger seated in 20C stated that when he moved to the right

side overwing exits, another passenger removed one of the exit hatches and handed it to him, and

he laid it in the adjacent seat. A third hatch was found adjacent to the aft window frame forward

of row 16, on the left side of the airplane. It was not determined how the left overwing exit

hatches were removed. Soot trails on the exterior of the aircraft extended up and aft from the

overwing exits and the forward doors. Photographs taken by a passenger and provided to the

Safety Board showed flames visible at the overwing exit and smoke at the forward and overwing

exits. (See figure 3.) The tailcone, aft of the rear pressure bulkhead, was in place and not burned.

In the cockpit, the emergency power switch was found in the “ON” position, and the

emergency lighting switch was in the “ARMED” position. The left and right engine fire handles

were in the aft, or activated position.12 Both fuel shutoff valves were in the closed position and

both fire suppression bottles had been discharged into the right engine.

1.13 Medical and Pathological Information

Five passengers sustained minor lacerations and contusions during the evacuation. They

were treated at the scene, transported to local medical facilities for hyperventilation and smoke

inhalation, and released the same day. The aft flight attendant sustained second degree burns on

her legs, and two puncture wounds above and below the inside of her left knee. She was wearing

shorts and a short-sleeved polo shirt—ValuJet’s flight attendant manual in effect at the time listed

standard uniform items for ValuJet flight attendants as trousers, shorts (optional), polo

 

12 Activation of the engine fire handles will silence the fire warning bell, secure fluid supply valves to the engines,

and select the fire suppression bottles. Subsequently turning the handles either clockwise or counterclockwise will

discharge the respective bottles.

14

shirt (short or long sleeve), sweater (optional), a jacket, white socks, and white shoes.

Unidentified pieces of the airplane debris were removed from the flight attendant’s leg by medical

personnel.

In accordance with ValuJet’s FAA-approved program, the flightcrew provided

postaccident toxicological samples for analysis. The samples were analyzed and found to be

negative for ethanol and other drugs of abuse. In addition, samples were requested from and

provided by the two flight attendants who were not injured. These were likewise negative.

Although a sample was requested from the flight attendant who had been injured, the request was

received after she had been hospitalized and treated for her injuries. Consequently, no

toxicological sample was obtained.

1.14 Fire

According to passenger statements, within seconds after the takeoff roll began, a sound

was heard that was described as a loud bang or explosion. Passengers reported looking rearward

in the direction of the sound and observing flames and fuel around the aft flight attendant. The

flight attendant seated in the forward jumpseat stated that within a few seconds after the takeoff

began, she heard a loud bang, saw flashes, and could clearly see smoke and flames around the feet

of the flight attendant seated in the aft cabin. The fire that began in the aft fuselage rapidly spread

through the airplane and consumed the fuselage.

1.14.1 Emergency Response

At 1908, the local control supervisor in the Atlanta Air Traffic Control Tower notified

the Atlanta Fire Department at the airport of the ValuJet emergency. Battalion 7 of the Atlanta

Fire Department was dispatched and arrived at the scene at 1911. Additional firefighting units

arrived on the scene at 1913. When the Atlanta Fire Department units arrived, all occupants had

evacuated the airplane. The two flight attendants in the forward section of the airplane and the

first officer reported that shortly after they exited the airplane following the passengers, the

firefighting vehicles arrived on scene. According to the Atlanta Fire Department report, arriving

units could see fire near the No. 2 (right) engine and heavy smoke emanating from all exits.

Firefighting personnel reported that the fire was spreading rapidly through the airplane from rear to

front. An interior attack was initiated on the cabin fire. According to firefighting personnel, after

noting the rapid progress of the fire along the overhead area and because the evacuation had been

completed, the firefighters retreated and continued fire suppression efforts from outside the

airplane. The fire was brought under control about 1922 and extinguished about 1925.

1.15 Survival Aspects

The cockpit was configured conventionally with two flight crewmember seats and an

observer jumpseat. No one occupied the observer jumpseat. The two flight attendants in the

forward section were seated on an aft-facing double-occupancy jumpseat attached to the cockpit

bulkhead, adjacent to the forward entry door. The flight attendant in the aft cabin was seated in a

forward-facing jumpseat attached to the aft cabin exit door.
15

About 1⁄2 of the available cabin seats were occupied. The ValuJet passenger manifest

listed one lap child. That lap child (a female) was older than 24 months old. Title 14 CFR Part

121.311(b) requires that all passengers more than 24 months of age be restrained during takeoff

and landing. According to passenger interviews, the child was seated on the lap of a female adult

in the 21-E window seat. During the evacuation, the adult handed the child to a male passenger

who carried the child through the right overwing emergency exit to another passenger who carried

the child across the wing and, holding the child, jumped off the trailing edge of the wing to the

runway without injury.

All exits and evacuation slides, except the tailcone exit (which was blocked by the aft

cabin fire), were unobstructed and were used during the evacuation. Some passengers who saw

the fire in the aft section of the cabin released their seat belts and moved toward exits before the

airplane came to a stop.

The captain reported that as he and the first officer were accomplishing the evacuation

checklist, the smoke in the cockpit became thick, black, and acrid, and was lowering rapidly. The

first officer reported that he was reading the evacuation checklist and had verified that the brakes

were set and that the spoilers were retracted, had lowered the flap handle, and had pulled the No. 1

engine fire handle (the captain had pulled the No. 2 handle), after which he could hardly breathe.

The first officer stated that he then yelled to the captain that “we’ve got to get out of here,” before

they were able to place the emergency light switch (the fourth, and next, item in the evacuation

checklist) in the “ON” position.

The captain reported that as the first officer stood up, he could not see him from the

chest up. According to the first officer, when he exited the cockpit into the cabin, he could feel

people walking past him but could see them only from the waist down. He stated that when he no

longer felt anyone passing by, he exited through the front left door of the airplane. The captain

stated that when he exited the cockpit, he dropped to the floor and could see “some distance down

the aisle, but only within about 3 to 4 inches of the floor.” According to passengers, the fire

spread rapidly and fully engulfed the cabin area within about 3 minutes after the engine failure.

Passengers reported that during the evacuation, the emergency floor track lighting

illuminated briefly but then extinguished. Also, as mentioned previously, the captain reported that

his initial attempt to broadcast the evacuation announcement over the PA system had not been

successful; he then moved the emergency power switch to the “ON” position (which caused the

emergency lights to turn off) and repeated the announcement.

One passenger reported that the injured flight attendant in the aft jumpseat was

struggling to release her seat belt and that as he moved aft to assist her, she released the belt and

moved forward to escape through a left overwing exit.

Several passengers described difficulty with visibility because of the smoke.
16

1.16 Tests and Research

1.16.1 Metallurgical Examinations

The Safety Board disassembled the failed engine at the AeroThrust Corporation in

Miami, Florida.13 Following the disassembly, parts, including the recovered portions of the failed

7th stage HPC disk, SN G78851, were taken to the Safety Board’s materials laboratory for further

examination. Maintenance records for the engine indicated that the disk had accumulated 24,101

hours and 16,340 cycles. It had a life limit of 30,000 hours or 18,932 cycles.14

The larger piece of the recovered disk was fractured circumferentially (see arrows “c,”

figure 4), which is typical of overstress. About 1⁄4 of the disk outward (toward the rim) of the bore

was separated and not recovered. There was a radial fracture of the disk bore at the position

shown by arrows “h1” and “h2” in figure 4. Examination of these fractures showed that they were

matching overstress separations and therefore accounted for the complete separation of the bore

section of the disk.

Twenty-four evenly spaced holes are machined in the web area of the disk. Twelve of

these holes are known as stress redistribution (SR) holes,15 also referred to as shielding holes in the

engine manual. Alternating with these SR holes are 12 slightly larger holes known as tierod holes,

through which the tierods are put to clamp the disk to the mating disks and spacers in the complete

engine assembly.

Figure 5 shows the aft face of the two recovered pieces situated relative to each other by

fracture matching. The SR holes are shown by arrows “1” through “9” and arrow “12” in figure 5.

The SR hole numbering was arbitrarily begun at the radial fracture plane indicated by arrows “A1”

and “A2” in figure 5 and progressed sequentially counterclockwise looking forward around the

disk (as shown in figure 5). The missing section of web would have contained SR holes “10” and

“11” in the above numbering sequence, and three tierod holes.

Scanning electron microscope (SEM) examination established that fatigue cracking

originated from numerous pits in the hole wall and progressed radially inboard (toward the center

of the disk) from SR hole “1,” approximately 6.9 millimeters (mm) (0.27 inch). SEM examination

also showed evidence of fatigue cracking outboard (toward the rim) from SR hole “1” that

measured 22.25 mm (0.88 inch). Figure 6 shows the fracture surface containing the primary

fatigue crack.

 

13 AeroThrust Corporation is an FAA-certificated repair station, and was one of the vendors used by ValuJet at

that time for the repair and overhaul of JT8D engines. Air New Zealand, (located in New Zealand) also an FAAcertificated repair station, was another vendor used by ValuJet for engine repair and overhaul of its JT8D engines.

14 The cycle life limit for the 7th stage disk SN G78851 was prorated from 20,000 cycles to 18,932 cycles, per

P&W procedures, because it had been previously operated in a higher-rated JT8D-15 engine.

15 Holes placed midway between the tierod holes to redistribute the stress in the web area between the tierod

holes.


19

Energy dispersive x-ray analysis of the pits on the hole wall revealed cadmium-rich

deposits16 with some nickel. Cadmium-rich deposits were also found on the fracture surface

adjacent to the pits and hole wall.

Visual and SEM examinations of the outboard fracture surface from SR hole “1”

showed extensive post-fracture smearing that obliterated most of the microscopic fracture features

on the fracture surface. However, some undamaged fracture areas were found that indicated an

origin area at the outboard wall of SR hole “1.” Features outside of the smeared region up to a

distance of about 3 mm (0.12 inch) showed a granular appearance with no evidence of striation

development. At this point, fatigue striation development was noted that continued outboard

approximately 22.25 mm (0.88 inch) from SR hole “1.”

Striation spacing measurements of the fracture surface of SR hole "1" were attempted but

hampered by the smearing in the fracture surface. The striation spacing in the granular type

fracture regions near the origin were possibly unresolvable or nonexistent. Striation spacings

outside of the granular fracture regions and smearing for the outboard fatigue crack from SR hole

“1” averaged about 2 microns (0.002 mm) from about 3 mm to the terminus at 22.25 mm. This

indicated that at least 9,500 striations (19 mm/0.002 mm per striation) were present along this

fatigue region.

Fatigue cracking was also evident radiating outboard from other SR holes, indicated by

arrows “4,” “6,” “8,” “9,” and “12” in figure 5. The largest of these fatigue cracks was 5 mm (0.20

inch) outboard from its respective hole. Most of the secondary cracks appeared to initiate at welldefined corrosion pits in the hole wall with the largest and deepest pit measuring 0.01-inch wide at

the hole wall and being about 0.003-inch deep. Magnified examination of the cross section of the

crack disclosed a surface deposit on the pit cavity wall and hole wall surfaces indicative of the

nickel-cadmium plating.

Fatigue striations with a fairly uniform striation density of approximately 2.5 microns

were clearly apparent near the terminus of the crack from SR hole “4” as well as near the termini

of the fatigue cracks from SR hole “1.” A P&W metallurgist indicated that spacings between 10

and 100 microinches (0.254 to 2.54 microns) are realistic spacings expected for low-cycle fatigue

cracking in the disk. Low-cycle fatigue cracking propagates from engine operation stresses that

occur in flight between each engine start and shutdown (flight cycle), and one striation is created

by one flight cycle.

The 0.88-inch fatigue crack outboard from SR hole “1” was the longest fatigue region at

any of the SR holes. The crack lengths from each side of the hole combined with the diameter of

the SR hole (0.410 inch) gave a calculated overall crack length of 1.56 inch for SR hole “1” at the

time of disk separation.

 

16 The disk is plated with a nickel cadmium (Ni-Cad) coating for corrosion protection during original manufacture.

It is also required to be chemically stripped and re-plated during certain inspections and repairs.
20

The only evidence of fatigue cracking inboard from an SR hole on the recovered pieces of

the 7th stage disk was that at SR hole “1.”

The 12th stage HPC disk from the accident engine (which was not damaged in the

accident) was examined at the P&W Metallurgical Laboratory in East Hartford, Connecticut, by

P&W and Safety Board metallurgists. Several tierod holes in that disk were found with corrosion

pits. Examination of a cross section through the pits confirmed that nickel and cadmium had been

plated onto the pitted surfaces of these tierod holes.

Two additional engines previously owned by THY and sold to ValuJet were available

for disassembly and examination of their 7th stage HPC disks by the Safety Board. Both 7th stage

HPC disks appeared in serviceable condition with no plating over pitting noted.

Three other engines also previously owned by THY and sold to ValuJet had been sent

by ValuJet to Air New Zealand for repair. The 7th stage HPC disks on these engines were

examined by Air New Zealand engineering for the Safety Board under the supervision and control

of the Civil Aviation Authority (CAA), New Zealand, and later at the P&W Metallurgical

Laboratory. Each of these disks had been retired because the total time and cycles were near the

hour and cycle life limit, and it would have been uneconomical to reinstall the disks and operate

them for the remaining hours or cycles before they had to be removed from service. Nickel and

cadmium plating over corrosion pitting in tierod and SR holes was confirmed on two of the disks,

and not found on the third.

No failures of the 7th stage HPC disk on any P&W JT8D engine have been reported

since 1975; however, on August 30, 1985, one failure was reported in Cameroon during taxi to

takeoff. The cause was never determined because the disk fragments could not be recovered.

1.16.2 Burn Tests of Cabin Furnishings

The need for fire retardant cabin furnishings on transport-category aircraft was first

addressed by the FAA in 1947. By 1972, FAA regulations required carpets, seats, and interior

panels to undergo Bunsen burner flammability tests. Subsequently, the FAA conducted additional

research and proposed upgrading these standards by adding toxicity, smoke, and improved

flammability criteria.

By 1977, there were still no full-scale burn tests to support the proposed rule and

standards, and the proposed rule was withdrawn. As a result, the FAA formed the Committee on

Special Aviation Fire and Explosion Reduction (SAFER), which conducted full-scale tests and

research and made recommendations for fire safety improvements. The technical information

developed as a result of these tests provided a standardized method of evaluating the suitability of

cabin materials.

On April 16, 1985, the FAA issued a notice of proposed rulemaking (NPRM) entitled

“Improved Flammability Standards for Materials Used in the Interiors of Transport Category

Airplane Cabins,” which became a final rule in 1985. The regulation established new fire test
21

criteria for type certification, required that the cabin interiors of airplanes manufactured after 1985

and used in air carrier service comply with these new criteria, and required that cabin interiors of

all other airplanes type certified after January 1, 1958, and used in air carrier service, comply with

these new criteria upon the first “general retrofit” of the cabin interior.

The accident DC-9 was manufactured before the effective date of the 1985 regulation and

therefore any retrofit of fire retardant cabin furnishings was required only in the event of a "general

retrofit" by the carrier. Piecemeal replacements of cabin furnishings, except for fire-blocked seat

covers, are not required to meet the new flammability standards. The FAA stated that this was

based on the adverse economic effect on the airline industry if the industry had to comply with the

new standard. Thus, it is reasonable to expect that if an air carrier applied this regulation, as

written, an airplane in service for 20 or more years might never be subjected to a “general retrofit.”

On August 15, 1995, burn tests of selected pieces of cabin furnishings from the accident

airplane were conducted at the Fire Safety Branch of the FAA’s Technical Center in Atlantic City,

New Jersey. A relatively undamaged carpet sample, sidewall panel sample, and a seat cover that

were collected from the rear of the accident airplane were tested. Testing was conducted in

accordance with the standard in effect before 1985, which required the Bunsen burner

flammability test. All of the components were directly exposed to the FAA’s Bunsen burner test

flame of 1,650 °F (1,500 °F is the minimum requirement) for 60 seconds. No ignition of the

materials occurred. Thus, all of the samples met the applicable (pre-1985) FAA test requirements

for flammability.

1.17 Additional Information

1.17.1 ValuJet’s Purchase of Turk Hava Yollari (THY) Aircraft, Engines, and Spare

Parts

1.17.1.1 Pre-delivery Activities in Turkey

In July 1994, ValuJet Airlines became aware that THY had several DC-9-32 aircraft and

engines for sale. ValuJet contracted with two independent consultants, who went to Turkey to

evaluate the aircraft and related equipment and their records, and to provide information that

would assist ValuJet in deciding whether to purchase the aircraft. After receiving input from the

consultants, ValuJet decided to execute the purchase.

In September 1994, ValuJet contracted with Avionics and Aircraft Systems Engineering

Services, Inc. (AAS), to provide aircraft and maintenance engineering assistance, on-site

management of the aircraft delivery program, and technical publication services in connection with

the acquisition and refurbishment of the THY aircraft. One of the original consultants, who was a

vice president at AAS, became the primary manager of the purchase and importation
22

process.17 On October 3, 1994, a formal sales agreement was executed between ValuJet Airlines

and THY for the purchase of nine aircraft, five spare engines (including the accident engine, SN

666966), and 4,400 spare parts.

Before ValuJet’s acceptance of any engine or aircraft, each was subjected to a ground

inspection that included the following:

• verification that all records and manuals were being delivered, and

that they were complete and current,

• a borescope inspection of all mounted and spare engines,

• verification that any structural damage had been repaired in full

compliance with the Aircraft DC-9 Structural Repair Manual or

approved McDonnell Douglas data,

• verification of aircraft airworthiness, and currency of U.S. FAA

airworthiness directives (ADs) on all aircraft,

• verification that cabin configuration changes requested by ValuJet

were accomplished by THY before removing aircraft from service

by Turkish Airlines,

• verification that all mounted engines were “serviceable” in

accordance with P&W engine manuals,

• verification that P&W Service Bulletins 4127 (noise attenuation)

and 2141 (oil dampened No.1 bearing) had been complied with on

certain engines,

• verification that the aircraft had been on a program in which the fuel

tank area was inspected for corrosion and microbiological

contamination, and

• inspection of the cabin for excessive wear or lack of cleanliness.

 

17 The consultant who became the primary manager had worked either as an employee or consultant for several

operators in the past. While working for these operators, he had at different times been responsible for writing FAAapproved maintenance programs, developing/managing a Part 121 aircraft acceptance program, directing a passengerto-freighter aircraft configuration conversion program, directing a cockpit/avionics standardization program,

developing several large aircraft FAA-approved supplemental type certificates, and developing the guidelines for the

DC-9 Structural Inspection Document program for the Douglas Aircraft Company.
23

In addition, each aircraft and the engines mounted on them for their ferry flight to the

United States were subjected to a regimented flight test program. According to the consultant, the

test flights, which were conducted by a ValuJet-contracted pilot, the AAS representative, and a

THY employee, were performed in accordance with the Douglas DC-9-32 Used Production Flight

Procedures Manual.18

The sales agreement between ValuJet and THY called for five of the airplanes to be

delivered with specific engines installed in specified positions. The remaining four airplanes could

be delivered with any of the remaining 13 engines installed in any location. Five of the engines

would then be delivered as spares.

The borescope inspection, which was conducted as part of the pre-sales agreement

discussed above, found that three of the spare engines and one mounted engine needed either

turbine blade or guide vane repair before they would be accepted by ValuJet. These four engines

were repaired and then tested. Because a test cell was not available, some of the engines in service

were removed from operating airplanes so that the repaired engines could be tested on an airplane.

Thus, engine SN 666966, which was being operated in line service at the time the consultant

arrived in Turkey, was removed from an airplane and became one of the five “spare” engines.

According to the AAS representative, the five spare engines were subsequently preserved by THY

in accordance with the P&W JT8D engine manual requirements.19

According to the sales agreement between ValuJet and THY, all spare engines were to

be certified as serviceable by an FAA-certificated Part 145 repair station before acceptance by

ValuJet. ValuJet and THY agreed that the spare engines would be certified as serviceable by the

THY repair station and then shipped to the United States with “serviceable tags.”20 According to

the consultant, the repair station prepared one of these tags for each spare engine. Entries on the

tag for engine SN 666966 describing the work done indicated that it had been removed from an

aircraft so that another engine could be installed and that it had been preserved for up to 90 days.

The consultant stated that as part of the preshipping process, he cross-checked the SN of each

spare engine with its associated tag.

According to the technical control director of THY’s repair station engine shop, THY

intended that the statement of serviceability and release for return to service on the “serviceable

tag” apply to more than just the work listed on the tag (in the case of engine SN 666966, removed

from aircraft and preserved), and represented a “full” statement of serviceability. He stated that in

 

18 This manual provides guidance on performing flight tests in a manner to demonstrate that the aircraft are

airworthy and that their systems are fully operational in accordance with their intended use.

19 This preservation process included purging the fuel system with mineral oil, installing desiccant and humidity

indicators inside the engine, and covering the intake, exhaust, and exhaust breather outlet with appropriate covers.

20 “Serviceable tags” are a commonly used method for repair stations to attach a written maintenance release

containing the information specified in FAR 43.9 to an aviation product to show that it is approved for return to

service.
24

his opinion, engine SN 666966 was able to be installed by ValuJet with no further inspections

needed, except for a depreservation inspection and any in-house inspections required by ValuJet.

According to THY’s technical control director, the tags that had been prepared for all

five spare engines were placed into a single large brown envelope and shipped to ValuJet along

with the remainder of the aircraft and engine records. The inspector stated that no tags were

attached to the engines for fear that they would be lost during shipment. The spare engines were

then air shipped to the United States and trucked to ValuJet’s facilities in Atlanta.

The AAS consultant stated that because the aircraft had been operated by a foreign

carrier, he evaluated the THY maintenance scheduling and recordkeeping system to confirm the

validity of the aircraft records and conformity with FAA requirements.21 As part of this process,

AAS reviewed all entries in the Aircraft Maintenance Log of each airplane for the last 2 years, or

since the last “D” check, whichever came last. AAS also reviewed the records of all mounted

engines, spare engines, and major components for the last 2 years, or since the last overhaul.

During this review, any entries that could not be accurately determined were translated into

English. In addition, other applicable records, such as FAA Forms 337 (Major Repair or

Alteration), AD and engine disk status records, and certain shop records associated with the repair

of spare parts, were translated into English.

According to the AAS representative, during this process, he reviewed the records to

verify a history of compliance, and compared compliance statements recorded in the maintenance

records to process documents executed at the time of the compliance action. As part of this

process, and in accordance with the guidance provided in FAA Order 8300.10, the accuracy of AD

compliance records was verified by spot checks of the aircraft. According to the AAS

representative, all requested documentation was provided, and he determined that the

recordkeeping system was valid.

The consultant also confirmed that the THY aircraft had been maintained in accordance

with the following documents/programs: McDonnell Douglas Aircraft Maintenance Planning

Document, DC-9/MD-80 Corrosion Prevention and Control Document, DC-9/MD-80 Aging

Aircraft Service Requirements Documents, and DC-9/MD-80 Life Limited Parts Document. At

the time of the purchase, these documents/programs were being used to maintain DC-9 aircraft

already operating in the ValuJet Airlines fleet; and these documents/programs became the basis for

phasing the THY aircraft into the ValuJet maintenance program.

When all pre-acceptance inspections were completed on an aircraft, it was deregistered

in Turkey22 and issued a “Certificate of Airworthiness For Export” by the Republic of Turkey

 

21FAA Order 8300.10 (Airworthiness Inspector’s Handbook), Bulletin A-92-04 (Current FAA Policy Regarding

Aircraft Records), dated 7/17/92, states that if an aircraft is being transferred from a foreign airline, it may be

necessary to evaluate the foreign operator’s maintenance and recordkeeping system to ensure the source validity of the

records. The bulletin provides a number of recommendations for determining the validity of the records, which then

become the basis for confidence in the current status of life-limited parts and AD compliance.

22 Deregistration is required by FAR 47.37. See also FAA Order 8130.2C, Chapter 6, Section 2.
25

Ministry of Transport and Communications. Each aircraft was then issued an FAA Temporary

Registration and an FAA Ferry/Environmental Permit by the ValuJet FAA principal maintenance

inspector (PMI). Each of the nine aircraft was then flown to Lake City Municipal Airport, Lake

City, Florida, where Aero Corporation began the process necessary for the aircraft’s return to

service in the United States.

1.17.1.2 Post-delivery Activities in the United States

A designated airworthiness representative (DAR) was contracted by ValuJet’s

consultant to issue the U.S. Standard Airworthiness Certificate for the nine aircraft. The DAR had

no involvement with the inspection, acceptance, delivery, or return to service of the five spare

engines and the approximately 4,400 spare parts purchased by ValuJet.23

While at ValuJet’s facility in Atlanta, engine SN 666966 was stored inside but did not

undergo humidity inspections at 30-day intervals as required by the P&W engine manual.

According to ValuJet’s Manager of Engineering, the inspections were not performed because

ValuJet’s general maintenance manual at the time did not include specific instructions for

conducting humidity inspections of stored engines. Since this accident, stored-engine inspection

procedures, consistent with P&W’s instructions, have been incorporated into ValuJet’s powerplant

and maintenance specifications.

Engine SN 666966 was subsequently shipped to the AeroThrust Corporation in Miami,

Florida, where P&W Service Bulletin 4127 (installation of noise attenuation equipment) was

complied with on January 21, 1995. The engine was then shipped to the Dee Howard Corporation

in San Antonio, Texas, on January 27, 1995, for installation on an aircraft.

According to the receiving and tagging instructions contained in ValuJet’s general

maintenance manual, when a serial-numbered component is received by ValuJet, the component is

to be tagged with the company’s equipment transfer record (ETR). Applicable information

regarding the item’s serviceability from the vendor’s tag or manufacturer’s certification is

transferred to the ETR, and copies of the ETR, along with the original vendor’s tag, are forwarded

to ValuJet’s Aircraft Records Department. One copy of the ETR remains attached to the

component, and installation and removal data are entered on this record when the component is

installed on an aircraft.

According to ValuJet’s general maintenance manual, Dee Howard’s inspection

procedures manual, and the aircraft maintenance agreement between ValuJet and Dee Howard,

engine SN 666966 should have been shipped to Dee Howard with a partially executed ETR

attached. The serviceable component tag would remain in ValuJet’s Aircraft Records Department.

The engine could then be installed by Dee Howard based upon the certification of airworthiness

inherent in the signature in block #10 of the ETR. However, according to Dee Howard’s manager

 

23 Title 14 CFR Part 21.175 requires airworthiness certificates for aircraft. An airworthiness certificate is not

required for unmounted engines or spare parts.
26

of quality assurance, engine SN 666966 arrived at Dee Howard without a ValuJet ETR or a

vendor’s tag from THY. The only document that arrived with the engine was the “Partial Repair

Item” tag executed by AeroThrust Corporation during the completion of P&W Service Bulletin

4127 (installation of noise attenuation equipment).

According to the manager of Dee Howard’s quality assurance, because the engine

arrived without documentation of its serviceability, Dee Howard requested that the on-site ValuJet

quality control inspector provide certification for the engine. Dee Howard was informed by this

inspector that a serviceable component tag had been issued by an FAA Part 145 foreign repair

station. The ValuJet quality control inspector on site (at Dee Howard) then executed ETR #14419

certifying the airworthiness of the engine. The investigation revealed that he did not review engine

records or a serviceable tag before doing so.

On February 9, 1995, after 106 days in preservation, engine SN 666966 was removed

from preservation to be installed in the No. 2 (right) position on N908VJ, the accident airplane, on

March 5, 1995. The engine and airplane were subsequently operated by ValuJet until the accident

on June 8, 1995.

1.17.2 1991 Overhaul/Inspection of 7th Stage HPC Disk by THY

Maintenance records obtained from ValuJet indicated that the 7th stage HPC disk had

been overhauled by THY during the time period from March 1991 to August 1991, and that the

disk had accumulated 18,477 hours and 11,907 cycles at that time. The records obtained from

ValuJet pertaining to the 1991 overhaul were limited to build records24 and logbooks documenting

the times and cycles of the engine, including the accident disk. However, no records were found

documenting each step of the overhaul of each individual disk, including what kind of an

inspection was performed on the 7th stage disk.25 (See appendix C for an example of this sort of

documentation, typically used in the industry.) THY personnel stated that all of the records that

pertained to the airplanes and engines purchased by ValuJet were transferred to ValuJet.

The Director of THY’s overhaul shop26 stated in a meeting with Safety Board staff that

the repair facility had performed a magnetic particle inspection (MPI)27 on the disk but during that

 

24 Build records are documents specific to each engine in which all component part numbers, SNs, certain

measurements, fits, and clearances or other special requirements are recorded in order of assembly.

25 Such documents, typically known as “shop travelers” or “process sheets,” break down the overhaul and

inspection process of a component into individual tasks, which include excerpts or references to the appropriate

manual, service bulletin, or job instruction card and a signature block for the technician or inspector performing the

task. (Hereinafter referred to as “process sheets” or similar documentation.)

26 The Director of THY’s overhaul shop was contacted by the Safety Board after the Safety Board obtained

information that P&W had conducted an engine shop maintenance review of THY in December 1991. See Section

1.17.5.1 later in this report for more details regarding that review

 27 Magnetic particle inspection (MPI) is a nondestructive method of detecting cracks and other defects in

ferromagnetic materials such as iron or steel. The inspection consists of magnetizing the part with high amperage DC

electricity thus creating magnetic lines of flux, then applying or immersing the part in a liquid containing
27

time had only inspected the tierod holes, not the SR holes, because the P&W engine manual only

required the tierod holes to be inspected. (See section 1.17.3 for more discussion on this.)

In response to the Safety Board’s inquiry about whether THY’s repair facility had

documented each step of the inspection and overhaul process, the Director of THY’s overhaul

shop provided the Safety Board, as a sample, a small card (slightly larger than a 3" by 5" card) that

had been used during the overhaul of a disk in 1995. The card had part identification and

operation data on one side, and handwritten notes about the repairs that had been done on the other

side. The card listed repairs for removing and replacing the nickel cadmium plating; however, it

did not list fluorescent magnetic particle inspection (FMPI),28 which is a required inspection

during disk overhaul, according to the P&W JT8D engine manual (see next section of this report).

The type of card displayed by the Director of THY’s overhaul shop was not found in any engine

record package for the failed engine.

In a letter to Safety Board staff dated June 18, 1996, the Director of THY’s overhaul

shop stated that an FMPI inspection had been used in July 1991 to inspect the 7th stage HPC disks

in JT8D engines. He stated that Turkish Airlines has had FMPI capability since the early 1970s

and improved the capability in 1978 and 1985.

He further stated that per Turkish Airlines’ procedures in 1991, nickel cadmium plating

would not have been removed from a JT8D HPC disk if there were 0.003-inch (or less) deep

corrosion pits on the surface of the disk, provided such pits were not located in the tierod/pin

holes, the bore area, and/or snap diameters. He further stated that it was necessary, in July 1991,

to inspect for and remove surface corrosion pits from within the SR holes only if their depth was

over 0.003 inch, based on the fact that the P&W engine manual did not list SR holes as a critical

inspection area and “it did not even show them in Figures 801 and 802 of the referenced section,

until subject section of the Manual was revised after June 1995.”

 

ferromagnetic particles in suspension. The ferromagnetic particles align themselves with the magnetic lines of flux on

the surface of the part forming a pattern. If a discontinuity is present in the material on or near the surface, opposing

magnetic poles form on either side of the discontinuity and the pattern is disrupted, forming an “indication.” The

indication assumes the approximate shape of the surface projection of the discontinuity; however, indications are more

visible when the defects are approximately perpendicular to the magnetic lines of flux. As a result, it may be necessary

to magnetize in more than one direction to reveal defects aligned parallel to the magnetic lines of flux.

The effectiveness of the MPI also depends on the flux density or field strength at the surface of the part when

the indicating medium is applied. As the flux density is increased, the sensitivity increased. However, excessively

high flux densities may form non-relevant indications.

28 FMPI is similar to an MPI except the ferromagnetic particles held in suspension are fluorescent such that

surface flaw indications luminesce under black light inspection.
28

1.17.3 Pratt & Whitney Guidance on Engine Overhaul/Inspection

The 7th stage compressor disk inspection instructions from the P&W JT8D Engine

Manual, Section 72-36-41, revision dated February 1, 1991, state that the following disk features

must be inspected very carefully: bore, tierod holes, snap diameter (front and rear) fillet radius,

pin holes, areas on the rim that touch blades, and for very early disks, balance flanges and balance

flange rivet holes. Graphic illustrations in the instructions (listed as figure 801 in the P&W

instructions) show the various features of the disk that were named in the text. (See figure 7.)

The P&W engine manual specifies that for area 7 of the P&W figure 802 (see

appendix D), which is depicted as a tierod hole, no unrepaired damage can be allowed in any hole,

or within 0.125 inch of the edge of the hole on adjacent surfaces, and that damage can be repaired

to a depth of 0.005 inch by blending. The instructions further indicate that damage up to 0.003

inch is acceptable in the web area of the disk without blending. The cross-section of the 7th stage

disk in P&W figure 802 depicts the tierod holes, but does not have the hidden lines,29 which would

depict the smaller diameter SR holes behind the tierod holes, or a separate cross-section of the

disk, just through the SR holes.

P&W JT8D Engine Manual Section 72-36-41, lists steps for overhauling the 7th stage

HPC disk (see appendix D) (steps that are incorporated onto “process sheets” or similar

documentation provided by airlines and Part 145 repair stations). The following summarizes the

overhaul steps:

1. Measure and record front and rear snap diameters, tierod hole

centerline in relation to rear snap diameter, and web thickness in

area contacted by spacers.

2. Strip existing nickel-cadmium plate.

3. Remove any residual rust after stripping nickel-cadmium.

4. Dimensionally inspect after removing old nickel-cadmium plate and

any previous plating repairs, measure front and rear snap diameters

and tierod holes.

5. Visually inspect all areas of each disk for pitting, galling, and other

defects.

6. Magnetic particle inspect per Task 72-36-00-24-000, Section 72-36-

00, Inspection 02. [This section and inspection refers to

 

29 Hidden lines, which depict the edges of a smaller feature located behind the larger feature, are shown on

orthographic projections as dashed lines.
29

TIEROD HOLES

~i.pws,91.E,,T.i:.-

Pratt & Whitney

JT8D ENGINE (PN 481672 - RESTRUCTURED)

COMPRESSOR DISK, STAGE 7 - INSPECTION-01

EXAMINE THE AREAS

THAT TOUCH THE

BLADE FOR GALLING

P

T

T

R

2

R

R

1’

RIM AREA ADJACENT

TO PIN HOLES

PIN HOLES

/

RIM

FILLET

RADIUS

R \ FILLET

RADIUS

‘ \ BORE

L–H0206

1. 0.125 Inch Maximum.

2. Electrical Contact Permissible Only In This Area. No

Burning, Pitting, or Selective Attack Permitted.

Important Inspection And

Electrical Contact Areas

Figure 801

(Task 72-36-41-22-000)

72-36-41

INSP-01

Page 803

EFF : -ALL FEB 1/93

000

Figure 7—P&W JT8D Engine Manual -- Compressor disk, stage 7-Inspection 01
30

fluorescent magnetic particle inspection.] Note: Inspection is

necessary after stripping even though disk may have been inspected

previously.

7. Make all necessary blending and machining repairs prior to plating.

8. Mask areas not to be plated leaving areas exposed that require

restoration or new plating.

9. Nickel plate areas not masked.

10. Machine nickel plated areas as required.

11. Nickel-cadmium plate entire disk.

1.17.4 FAA Regulations Regarding the Return to Service of the Spare Engines

Federal regulations require that the following specific information be entered in the

maintenance record of any item on which work has been performed: a description of the work

performed; the date the work was completed; the name of the person who performed the work; and

the signature, certificate number, and kind of certificate held by the person who approved the

work. The signature constitutes the approval for return to service only for the work performed,

and this maintenance record entry must be made before any person can return an engine to service.

The regulations further state that the holder of a repair station certificate may approve an

aircraft, airframe, engine...for return to service.30 The regulations also provide that before an

engine can be returned to service it must have been inspected by a qualified inspector and that the

maintenance facility must certify in the maintenance record that it is airworthy with respect to the

maintenance performed. The qualified inspector must be an individual who has shown by

experience as a journeyman that he or she understands the inspection methods, techniques, and

equipment used in determining the airworthiness of the article concerned.31

Common industry practice is to include the following statement, or words to this effect,

on the serviceable tag:32

 

30 See 14 CFR Section 43.5 (Approval for return to service after maintenance, preventative maintenance,

rebuilding, or alteration.); Section 43.9 (Content, form, and disposition of maintenance, preventative maintenance

rebuilding, and alteration records.); and Section 43.7 (Persons authorized to approve aircraft, airframes, aircraft

engines, propellers, appliances, or component parts for return to service after maintenance, preventative maintenance,

rebuilding, or alteration.); and Section 145.51 (Privileges of repair station certificate.).

31 Title 14 CFR Part 145.59 (a) and (b) (Inspection of work performed.).

32 This language is required in maintenance entries for major repairs or alterations. (See Appendix B to FAR Part

43, Par. (b)(4).) Not all serviceable tags document major repairs or alterations.
31

The aircraft, airframe, aircraft engine, propeller, or appliance identified above

was repaired and inspected in accordance with current FAA regulations, and

is approved for return to service. Pertinent details of the repair are on file at

this repair station under Order No.____.

FAA Advisory Circular 145-3 (Guide for Developing and Evaluating Repair Station

Inspection Procedure Manuals (IPMs)) Appendix F, Figure 34 (Final Inspection and Release to

Service) provides this sample language for a repair station IPM: “Aircraft components, appliances,

and other items, other than complete aircraft, repaired or overhauled as authorized by the repair

station specifications, will be returned to service through the use of a maintenance release

preprinted on the serviceable parts tag described by this section of the manual.”

With respect to the scope of work authorized by foreign repair stations, the regulations

state that a certified repair station may, with respect to U.S.-registered aircraft, maintain or alter

aircraft, airframes, powerplants, propellers, or component parts. The regulations further state that

after major repair or alteration, a certified repair station (domestic or foreign) can return to service

only articles that have been worked on according to technical data approved by the FAA

Administrator.33

Federal regulations require that domestic repair stations keep records of work performed

for at least 2 years; foreign repair stations are exempt from these recordkeeping requirements.34

However, foreign repair stations are required to keep records of maintenance performed on U.S.-

registered aircraft containing basic details and whatever additional information the FAA

Administrator finds necessary regarding U.S.-registered aircraft.35 The regulations do not specify

how long such records must be kept. However, the FAA generally specifies a time period in the

repair station’s inspection procedures manual.

FAA Order 8130.2C (Airworthiness certification of aircraft and related products)

Section 3 (aircraft engines, propellers, materials, parts and appliances), paragraph 220, states that

the person who returns an imported product to service (in accordance with 14 CFR Part 43.5) must

ensure that the product:

• has not been modified, changed, or damaged subsequent to the time

of export certification;

• complies with all FAA ADs;

 

33 Title 14 CFR Part 145.73 (Foreign repair stations—scope of work authorized.) and Part 145.51 (Privileges of

certificates.).

34 Title 14 CFR Part 145, Subpart B and C.

35 Title 14 CFR Section 145.79.
32

• is installed in accordance with FAA-approved design data;

• is found to be in condition for safe operation; and

• is accompanied by the necessary maintenance documentation.

1.17.5 THY Repair Station

THY operates a repair station that is certified by both the FAA and the Director General

of Civil Aviation (DGCA) in Turkey. The repair station maintains and overhauls airplanes that are

part of the Turkish Airlines fleet as well as airplanes and engines operated by foreign and domestic

operators. Authority granted by the Turkish DGCA allows the repair station to overhaul JT8D

engines for the THY fleet. THY receives its authority to overhaul JT8D engines for U.S.-

registered airlines from the FAA.

According to its FAA Air Agency Certificate, first issued in 1974, and its Repair Station

Operations Specifications, which are periodically reissued and revised by the FAA, THY has been

an FAA-certificated 14 CFR Part 145 Subpart C repair station since March 8, 1974, with the

following ratings: airframe, powerplant, instrument, accessory, radio, and limited specialized

service. Before 1986, its operations specification limitations listed Airframe Class 4 (all-metal

large aircraft) and Powerplant Class 3 (turbine engines), without further limitation to specific

airframes or engines.

The revised operations specification issued on November 21, 1986,36 listed “Limited

Ratings”37 for Airframe to include: Airbus Industries A300 and A310 series, Boeing B707/720,

and B727 series, Fokker F28 series, McDonnell Douglas DC-9 and DC-10 series, and other

airplanes; and for Powerplant to include: General Electric CF6 series, P&W JT3D, JT8D, JT9D,

and PT6A series, and various Rolls Royce engines. A note under the powerplant limited ratings

stated the following:

LINE MAINTENANCE FOR OTHER ENGINES IN THE CLASS 3 CATEGORY.

AUTHORIZATION IS LIMITED TO MINOR INSPECTIONS, REMOVAL/ INSTALLATION

OF ACCESSORIES AND COMPONENTS, ADJUSTMENTS, MINOR REPAIRS, MINOR

ALTERATIONS ONLY. WORK TO BE ACCOMPLISHED IN ACCORDANCE WITH THE

MANUFACTURER’S TECHNICAL DATA OR OTHER PROCEDURES ACCEPTABLE TO

THE [FAA] ADMINISTRATOR.

 

36 See appendix E for examples of THY’s repair station operations specifications.

37 Limited ratings are ratings issued to repair stations for the performance of maintenance on particular makes and

models of airframes, powerplants, propellers, radios, instruments, accessories, and/or parts. (8300.10 (Chapter 161,

Section 1, paragraph (8) FAR 145.33.))
33

The Safety Board was unable to obtain the THY Repair Station Operations

Specifications that were applicable between November 1989 and October 1991. The Board did

examine the operations specifications in force for the period ending November 23, 1989, and the

period beginning October 29, 1991. Both of those operations specifications included limited

ratings for P&W JT8D and other engines and contained the same note, quoted above: “Line

maintenance for other engines in the Class 3 category. Authorization is limited to minor

inspections....”

The statement addressing line maintenance of other engines in the Class 3 category

remained unchanged until August 4, 1994, when the entire note under powerplant limited ratings

was revised to read:

POWERPLANT AUTHORIZATION FOR THE AFOREMENTIONED ENGINES INCLUDES

MAINTENANCE AT ALL LEVELS UP TO AND INCLUDING OVERHAUL IN

ACCORDANCE WITH CURRENT MANUFACTURER’S MAINTENANCE MANUALS OR

OTHER FAA APPROVED DATA. MAINTENANCE (EXCLUDING OVERHAUL) IS

LIMITED TO ENGINES INSTALLED ON AIRCRAFT LISTED IN THE AIRFRAME

RATINGS AND FURTHER LIMITED TO THOSE MAINTENANCE FUNCTIONS AS

AUTHORIZED BY THE CURRENT MANUFACTURER’S MAINTENANCE OR FAA

APPROVED DATA.

Under “Specialized Service,” the October 29, 1991, Repair Station Operations

Specifications listed the following nondestructive testing methods: ultrasonic; magnetic particle

per MIL-I-25135 and MIL-SAD-6868, as revised; eddy current per MIL-SAD-1537A, as revised;

penetrant-visible dye and fluorescent dye per MIL-SAD-6866, as revised; and radiographic x-ray

per MIL-SAD-453C, as revised.

THY maintains that it was authorized by the Turkish DGCA to operate a turbine-engine

repair station and to overhaul P&W JT8D and other engines. However, THY maintained that it

“...clearly understood from operations specifications of Turkish Airlines that THY [was]

authorized to make any kind of repair and overhaul of JT8D engines. Turkish Airlines

repair/overhaul certification for JT8D engines has never been discontinued between 1974 and

1996.”

Following the accident, by memorandum dated November 16, 1995, the Safety Board

was advised by the FAA’s Director of Flight Standards Service (AFS-1) that the THY repair

station had not been decertified at any time since the 1974 issuance of its original repair station

certificate. However, he reported that THY’s Class 3 powerplant rating had been changed to

limited powerplant, excluding overhaul, on November 21, 1986, and that the FAA’s “files do not

contain any information relative to this change other than the certificates themselves.” AFS-1

reported that THY was again authorized to overhaul JT8D engines on August 4, 1994.

The PMI who was assigned surveillance responsibilities at THY from 1992 to 1995

stated that although THY retained the capability to conduct JT8D overhauls after 1986, THY had

no need for FAA-granted overhaul authority from the FAA until 1994, because of inactivity

involving U.S.-registered airplanes. Reauthorization of foreign operations specifications was, at

that time, dependent on annual activity in support of U.S.-registered airplanes. He stated that he
34

was confident that THY understood its 1986-1994 limitation because he received a phone call

from THY in 1994 requesting that THY’s FAA repair station authority be expanded to include

overhauls on various engines.

According to the PMI, the PMI, along with a three-man team, subsequently conducted a

3-day inspection that resulted in the amended THY repair station operations specifications dated

August 4, 1994, which authorized overhauls of CF6, JT3D, JT8D, JT9D, and PT6A series engines.

The amended operations specifications also added D-check authorizations for Airbus Industries

A310, A340, Boeing 707/720, 727, 737, Fokker F28, McDonnell Douglas DC-9 and DC-10, and

other airplanes.

THY maintains that the FAA never informed it of any change to its authority to

overhaul JT8D or other engines and that THY has never requested such a change to its operations

specifications. THY reported to the Safety Board that it has always maintained and overhauled

P&W engines in accordance with manufacturer maintenance and overhaul manuals and standards

and that this is also a requirement for certification as a repair station by the Turkish DGCA.

1.17.5.1 Pratt & Whitney Engine Shop Maintenance Review

During the investigation, the Safety Board discovered that P&W engineering personnel

had conducted a Turkish Airlines JT8D Engine Shop Maintenance Review in December 1991.

THY provided a copy of the review to the Safety Board. The report noted that the THY shop had

been set up to handle a maximum of 50 JT8D shop visits per year and that it was averaging

approximately 35 shop visits per year. The P&W review contained conclusions/

recommendations, including the following:

• Conclusion: Turkish Airlines’ shop personnel are experienced and

know the procedures for cleaning, stripping, plating, and other

repairs; however, new personnel sometimes enter the shop, and

procedures are sometimes revised. Because the Engine Manual is

written in English and presents a generic view of each procedure,

Turkish Airlines should prepare process sheets that 1) describe the

specific processes and repair procedures in Turkish, 2) describe

actual shop equipment used at Turkish Airlines, and 3) require shop

personnel to sign each significant step of the procedure as that

procedure is completed. Process sheets will help avoid many repair

problems and will confirm that the complete, up-to-date procedure

has been accomplished. These sheets can also be used in a

computerized parts tracking system.

• Recommendation: Prepare specific, Turkish-language process sheets

for parts sent into the shop.

• Conclusion: Many of the parts racks are dirty. Clean parts can

become dirty enroute to the FPI [fluorescent particle
35

inspection]/FMPI area, which can lead to contamination of the

expensive FPI penetrants.

• Recommendation: Periodically steam clean the parts racks.

• Conclusion: The job card that routes the parts through FPI and FMPI

does not specify the process or have a sign-off line for the inspectors

to see that the work has been done. The only indication that the

parts have been FPI inspected is a green wire attached to the parts.

Several parts were found with green wires attached without any

evidence of background fluorescence that is typical of parts that

have been processed through the FPI line.

• Recommendation: Specify the FPI or FMPI SPOP on the work order

with a sign-off line for the inspector to permit the inspection process

to be verified and the inspector for that part to be identified.

1.17.5.2 FAA Inspections of THY Repair Station

The Safety Board staff reviewed FAA Program Tracking and Reporting System (PTRS)

records and correspondence between the FAA and THY to determine the frequency and level of FAA

oversight of the THY repair station. The PTRS records, which were only available from June 1993

to the present, typically reflected one to three visits per year with mostly favorable but some adverse

comments that required corrective action. These records were not as detailed as the 1991 P&W

JT8D Engine Shop Maintenance Review, but included checklists and indicated relatively

comprehensive inspections of the facility.

Additional correspondence pertaining to FAA oversight and recertification of THY

addressed the periodic renewals of the THY Air Agency Certificate and Repair Station Operations

Specifications and provided the results of FAA inspections in connection with those renewals. The

Safety Board found that the renewals followed FAA inspections of the THY facility after 1- or 2-year

intervals. The FAA required correction of the listed inspection discrepancies in advance of

reissuance of repair station certificates. For example, in its September 5, 1991, letter to THY, the

FAA PMI advised the repair station:

Turkish Airlines NDT [non-destructive testing] area must be audited by the company

and new procedures implemented. Calibration of black lights and calibration meter

must have records of calibration by Mil-Std. Also X-ray must have a means of

checking the film after X-ray by use of the penetrameters or by using a densitometer

to measure density. This office recommends the supervisor of the NDT shop receive

addition[al] factory training in all areas of NDT to update personnel assigned. Eye

examination per Mil-Std-410 are (sic) required for all NDT personnel.
36

Corrective action of these discrepancies was required within 60 days and, according to FAA

correspondence, was accomplished by THY in advance of the reauthorization of the operations

specifications, which occurred on October 29, 1991.

The FAA PMI with oversight responsibility for THY from 1992-1995 stated that renewals

were sometimes extended to 2-year intervals because of FAA staffing shortages; he reported that in

1992, his office (International Field Office, Frankfurt, Germany) had only six persons to inspect,

certify, and surveil all of the Part 145 Repair Stations in Europe; as the number of such stations grew,

his office grew to its 1995 staffing level of 20 inspectors. He stated that he was personally

responsible for 21 repair stations in 1992.

The FAA correspondence indicated that reauthorization of the operations specifications

was in part dependent on annual activity in support of U.S.-registered airplanes. The application

dated August 31, 1991, stated that the specifications were to be reauthorized despite no such work in

the previous 3 years. The correspondence indicated that the THY repair station activity involving

U.S.-registered airplanes was quite limited in other years as well, although contracts with two U.S.

air carriers have increased that activity since 1992.

A four-person FAA team performed an inspection of the THY repair station from

June 27 through 29, 1995. This inspection, which, according to the FAA, had been planned before

the accident, was to recertify Turkish Airlines’ Part 145 repair station certificate. As a result of the

accident, the team assigned two personnel to focus on areas relating to the accident investigation.

A memorandum documenting the inspection indicated that the inspection team included the PMI,

another maintenance inspector, an avionics inspector, and an engineer from the Aircraft

Certification Office in Brussels, Belgium.

According to the memorandum, the inspection team focused on two issues: (1) FAA

recertification of THY’s Part 145 certificate, and (2) information regarding turbine engine

maintenance. The memorandum stated that based on the audit reports of the engineer and one of

the maintenance inspectors, it appeared that the repair station’s methods, techniques, and practices

were satisfactory at the time of the inspection.

In the maintenance inspector’s report, which was attached to the memorandum, the

inspector commented about THY’s compressor disk repair capabilities. He stated that the correct

P&W maintenance manual was available and that the disk repair procedures used were P&W’s

instructions. According to the inspector’s report, the technicians could read and speak English and

were familiar with the process for corrosion identification and removal. The work station in the

visual inspection area was reported to be well lighted and the tools for blending surface damage

were appropriate. The report also stated that in the plating shop, the procedures were available in

both English and Turkish.

The engineer’s report, which was also attached to the memorandum, indicated that THY

overhauled its own engine compressor disks after a maximum of 4 years, compared with the FAA

Airworthiness Directive (AD) 94-20-01 requirement for overhaul at a maximum of 10 years.

According to the report, this action was taken because THY had purposely left a plated tiebolt, of
37

the same material and plating as a disk, outside for 1 year and found that it developed corrosion

under the plating.

One of the inspectors’ reports attached to the memorandum stated that none of the

overhaul records for the failed engine were available at THY at the time of the FAA inspection.

1.17.6 ValuJet’s Flight Attendant Training Program

Federal regulations38 require that certain emergency drills be conducted by

crewmembers, including flight crewmembers, during initial training and recurrent training at 24-

month intervals. The regulations state, in part, that crewmembers shall perform emergency exit

drills, operating each type of emergency exit in both normal and emergency modes and that the

drills shall replicate the actions and forces required in the deployment of the emergency evacuation

slides.

FAA Air Carrier Operations Bulletin (ACOB) 8-76-6, “Guidelines for Crewmember

Training on Aircraft Tailcones and Approval of Tailcone Training Devices,” dated July 13, 1992,

allowed air carriers to train their DC-9/MD-80 crewmembers by having an instructor or trainee

operate the tailcone release handle while other trainees observed. ACOB 8-76-6 was current at the

time that ValuJet was certificated on October 21, 1993, and it was current on August 30, 1995,

when the FAA was queried by Safety Board investigators regarding the ACOB’s status.

On January 26, 1996, the FAA issued Flight Standards Handbook Bulletin 96-02,

“Guidelines for Crewmember Training on Aircraft Tailcones and Approval of Tailcone Training

Devices.” This bulletin set forth acceptable means of approving tailcone training devices and

required that each trainee actually operate the appropriate mechanisms to ensure evacuation

through the tailcone exit.

ValuJet Airlines’ flight attendant training program, which included crewmember exit

drills, was approved by the FAA in a letter dated September 23, 1993, to ValuJet’s Vice President

of Marketing. ValuJet’s flight attendant training syllabus in effect at the time of the accident, and

which also was approved by the FAA, did not address tailcone exit drills. However, ValuJet’s

Manager of Inflight Training stated that exit drills were conducted on an actual airplane, during

which crewmembers simulated pulling the tailcone release handle, rather than actually operating

the tailcone exit. Additionally, passenger entry door and service door training was conducted on

ValuJet airplanes, during which bungee chords were attached to the doors to simulate the forces of

the emergency evacuation slide being pulled from its bustle. According to ValuJet, pilots

participated in the same drills as the flight attendants. After this accident, ValuJet acquired a

tailcone exit training device and trained all active flight attendants with the use of this device by

the end of August 1995.

 

38 Title 14 CFR Section 121.417.
38

Several errors in ValuJet’s DC-9 flight attendant manual were noted by Safety Board

investigators. For example, although the correct operation of the tailcone exit was described, an

illustration for an MD-80 aft entrance door was used rather than an illustration for the DC-9-32

airplane operated by ValuJet. Also, a diagram for the tailcone interior jettison handle stated “Note

Tailcone is normally jettisoned using the passenger aft entrance door emergency handle.” This

referred to MD-80 aircraft and not the DC-9-32 airplane. Another diagram depicted ValuJet’s

airplanes as having both a tailcone exit door and an exit hatch, although ValuJet does not operate

any DC-9 aircraft with a hatch.

The flight attendant manual also contained incorrect information, or lack of information,

regarding flight attendant flotation equipment, passenger safety announcements, flight attendant

operation of the cabin emergency lighting switch, and use of the water fire extinguisher. The

Manager of Inflight Training, who was hired in March 1995, stated that the flight attendant manual

was in the process of being revised at the time of the accident. ValuJet issued a new flight

attendant manual on November 11, 1995. (See Appendix F.) The new manual does not contain

the errors found in the previous version.

1.17.7 Safety Board Recommendations Subsequent to the Accident

Following the accident, on July 6, 1995, the Safety Board issued three safety

recommendations to the FAA regarding the failure of the accident engine, the wording of P&W

repair guidance, and FAA guidance to maintenance personnel. The Safety Board stated in its

recommendation letter that the metallurgical examination of the 7th stage HPC disk from the

ValuJet engine showed that the failure was caused by fatigue cracking that had originated at a

corrosion pit in an SR hole. The letter stated that there was evidence that the corrosion pit had

been plated over during an overhaul of the disk in 1991, and that, additionally, it appeared that the

size of the corrosion pit exceeded the allowable limits at the time of the overhaul.

The letter further stated that examination of the fatigue crack revealed a minimum of

7,000 to 8,000 fatigue striations. The letter concluded that, assuming that each striation

represented one “flight cycle,” based on the 4,433 flight cycles accumulated since the last

inspection, the crack would probably have been detectable by non-destructive testing or by visual

inspection at the time that the engine was last overhauled.

As a result, the Safety Board issued the following urgent Safety Recommendation A-95-

71 to the FAA:

Issue an Airworthiness Directive to require the inspection of Pratt & Whitney

JT8D engine high pressure compressor steel disks that were last overhauled

and maintained by Turk Hava Yollari of Turkey prior to reaching 3,000

cycles since that last overhaul and inspection. Special attention should be

given to the potential for corrosion pitting or cracks in the shielding [SR]

holes in 7th stage high pressure compressor disks.
39

On September 14, 1995, the FAA reported that on July 10, 1995, a Telegraphic

Airworthiness Directive (AD), T95-15-51, was issued that was applicable to certain P&W JT8D

engines containing HPCs that had been inspected by THY. The AD required that those engines

containing any 7th through 12th stage HPC disks that had accumulated 2,900 or more cycles on the

effective date of the AD or 100 cycles in service after the effective date of the AD, whichever

occurred first, be inspected in accordance with the P&W JT8D engine manual for evidence of

corrosion pitting and cracks. According to P&W, no cracks were found in any of the inspected

disks. The Safety Board responded that the action satisfied the intent of the recommendation,

which was then classified “Closed—Acceptable Action.”

The Safety Board also stated in its recommendation letter that it noted that P&W engine

manuals provided overhaul facilities with inspection guidance, allowable limits for damage, and

repair procedures. The Safety Board stated that the inspection material was quite detailed but that

it could be difficult to understand. It was noted that such misunderstandings could be magnified

when translating the instructions from English into another language. Consequently, the Safety

Board issued Safety Recommendation A-95-72, asking the FAA to:

Modify the wording of the inspection and damage limits provided in the Pratt

& Whitney manuals and service bulletins for JT8D high pressure compressor

steel disks to prevent any misunderstanding of the amount of damage allowed

and the procedures required for the repair and return to service of the disks.

On September 14, 1995, the FAA reported that it was working with P&W to modify the

engine manual as requested. On November 20, 1995, the Safety Board classified this

recommendation “Open—Acceptable Response.” By letter dated June 4, 1996, the FAA reported

that the JT8D engine manual was revised to clarify the amount of damage that is allowed and the

procedures required for the repair and return to service of the disks.

However, the Safety Board has noted that the revised inspection sections for the 10th,

11th, and 12th stage HPC disks incorrectly show those disks as having SR holes. In addition, the

inspection section for the 13th stage HPC disk, which is made of a non-magnetic nickel alloy, was

revised to add an FMPI, which would only be appropriate for parts made of alloys that can be

magnetized. Consequently, pending further modifications of the JT8D engine manual to correct

these inaccuracies, Safety Recommendation A-95-72 remains in an “Open—Acceptable

Response” status.

The Board also issued Safety Recommendation A-95-73, which asked the FAA to:

Provide additional guidance to designated airworthiness representatives and

aviation maintenance personnel to ascertain whether facilities that have

repaired or overhauled aircraft, aircraft engines, and aircraft equipment

submitted for acceptance in the United States held the proper Federal

Aviation Administration certificates at the time the work was accomplished.
40

 In either event, the guidance should include the actions to be taken to ensure

compliance with the Federal Aviation Regulations.

On September 14, 1995, the FAA reported that a flight standards information bulletin

(FSIB) would be issued. The FSIB would remind FAA inspectors and designees of their

responsibility to ensure that aircraft, aircraft engines, propellers, and other parts imported or

accepted into the United States meet the requirements of the FAA regulations and follow

established FAA policy and guidance. The FAA subsequently issued FSIB for Airworthiness

(FSAW) 96-14, effective July 5, 1996. The Safety Board found the FSAW responsive to the intent

of Safety Recommendation A-95-73, and the recommendation has been classified “Closed—

Acceptable Action.”
41

2. ANALYSIS

2.1 General

The flightcrew was properly certified and trained for the flight, and was in compliance

with the Federal regulations on flight and duty time. The flight attendants had completed

ValuJet’s FAA approved flight attendant training program in existence at the time of the accident.

The airplane was properly certificated and operated in accordance with applicable Federal

regulations. The aircraft certification process followed by the DAR was thorough and complete in

that all required aircraft and record inspections were performed. The DAR’s airplane certification

process was not considered relevant to the accident sequence. Visual meteorological conditions

prevailed, and weather was not a factor in the accident.

2.2 Uncontained Engine Failure

An uncontained failure of the right engine occurred at low speed, early in the takeoff

roll. The rapid decrease in the EPR of the right engine recorded on the DFDR was the result of the

uncontained failure of the right engine. As a result of the uncontained failure, engine shrapnel

penetrated the fuselage, severing the right engine main fuel line. Pressurized fuel sprayed into the

cabin near the aft lavatory and was most likely ignited by sparks generated by steel engine

fragments contacting steel galley equipment in the cabin.

Postaccident examination of the failed right engine revealed that the 7th stage HPC disk

was fractured. Metallurgical examination of the two major pieces of the disk that were recovered

revealed fatigue cracking in the SR hole “1” location in the larger piece of the 7th stage disk. The

combined fatigue crack lengths and hole diameter accounted for an overall crack length of 1.56

inches at SR hole “1.” Also, the crack at SR hole “1” contained the largest outboard propagating

fatigue crack and the only inboard propagating fatigue crack found on the disk. This combined

fatigue crack length is consistent with a critical crack length expected to produce separation of the

disk under normal operating conditions. Also, because this fatigue crack was the only one on a

radial fracture plane that went completely through the section between the bore and rim, it was

likely the primary fracture initiation area.

Although the fracture was heavily damaged, analysis of fatigue striation measurements

in the outboard fatigue region from SR hole “1” indicated that a crack of about 12 mm

(approximately 1⁄2 inch) existed in the disk at the last reported overhaul in 1991, or 4,430 engine

cycles before the disk failure.39 Thus, the Safety Board concludes that a detectable crack40 existed

 

39 Fatigue striation measurements in the outboard fatigue region from SR hole “1” gave estimated uniform

spacings of 2 microns between 10.5 mm and 15.5 mm crack lengths and an estimated uniform 2.5 micron spacing from

15.5 mm crack length to the fatigue terminus at 22.25 mm from the hole. These measurements were used to estimate

the approximate crack length at the last inspection reported as 4,430 engine cycles before disk failure. The fatigue

striation spacings of 2.5 microns and less were consistent with fatigue striation development from low cycle fatigue,

which equates to one striation for each flight cycle. The final stages of fatigue cracking were used to calculate the

amount of cracking to account for the last 4,430 striations, as follows: (22.25 mm minus 15.5 mm) or 6.75 mm of

crack propagating at 0.0025 mm (equivalent to 2.5 microns) per cycle yields 2,700 cycles for this region; (4,430 cycles
42

in an SR hole in the 7th stage HPC disk of engine SN 666966 when the disk was overhauled by

THY in 1991, and therefore detectable by FMPI or MPI.

Fatigue crack initiation at SR hole “1” and others was linked to corrosion pits, some as

deep as .003 inch, in the SR holes that were shown to be plated over with nickel cadmium (see

figure 8). Although the investigation could not determine when the pits were plated over, the

plating over of the pits indicates that they existed in the disk during the overhaul inspection by

THY in 1991, as that would have been the last time before the accident that the disk would have

been off the engine. Plating over pitted surfaces also existed in several tiebolt holes on the 12th

stage disk of the accident engine.

2.3 Overhaul Procedures by THY

The size of the fatigue crack and the plating over corrosion pits in the SR holes indicate

that during the overhaul of the 7th stage disk by THY in 1991, a proper inspection was not

performed. The Director of THY’s overhaul shop initially contended that because the P&W

engine manual did not specifically refer to the SR holes, only the tierod holes needed to be

addressed in the overhaul inspection. Later in the investigation, the Director indicated that an

inspection41 of the SR holes had been performed but to a different standard than that for the tierod

holes--one that permitted scattered surface damage up to 0.003-inch deep to go unrepaired.

If the THY repair station did perform an inspection of the disk, including the SR hole

“1,” but did not repair the damage or reject the part because the damage was limited to corrosion

pits of 0.003 inch or less as the Director of the THY overhaul shop contends, this raises some

concerns. First, the P&W engine manual states that no unrepaired surface damage is allowed in

any hole or within 0.125 inch of the edge of a hole on adjacent surfaces. If THY was uncertain

about how this statement applied to the SR holes, THY should have discussed this with P&W

technical representatives to clarify any uncertainties.

More importantly, however, a properly performed inspection should have detected a

crack estimated to be 1⁄2-inch long at the time of the THY overhaul in 1991. During an MPI

inspection, the entire disk is magnetized, and magnetic particles are applied to the disk. The SR

holes would inescapably be included in this type of inspection because of their proximity to the

 

minus 2,700 cycles) or 1,730 cycles at 0.002 mm (2 microns) per cycle yields 3.46 mm; therefore, a crack of 6.75 mm

plus 3.46 mm equals 10.21 mm to propagate the last 4,430 cycles. Because this crack had an overall length of 22.25

mm at failure of which the last 10.21 mm occurred since last inspection, then approximately (22.25 mm minus 10.21

mm) or 12.04 mm of crack length existed at the last inspection.

40 A 12-mm crack extending the depth of SR hole “1,” and extending to the front and rear faces of the disk would

have a probability of detection of 100 percent when inspected with either FMPI or MPI according to the current

Nondestructive Testing Information Analysis Center nondestructive evaluation capabilities data book.

41 It is unclear what type of inspection THY performed, based on conflicting statements by the Director of THY’s

overhaul shop. In a meeting with Safety Board officials, he claimed that an MPI inspection was performed. However,

subsequently, in a letter dated June 18, 1996, he stated that an FMPI was performed.

44

tierod holes, and the 1⁄2-inch crack would have been readily visible, not only inside the SR hole, but

along the surface of the disk. During an FMPI inspection, the entire disk is not only magnetized,

but is also covered in a solution containing fluorescent iron particles that would further highlight

any defects. Accordingly, the Safety Board concludes that THY did not perform a proper

inspection when the disk was overhauled in 1991. Had the THY repair station accomplished a

proper inspection of the 7th stage high compressor disk of engine SN 666966, the crack would

probably have been detected, the part rejected, and consequently, the accident may have been

avoided.

Because of the Director of THY's overhaul shop’s earlier comments that the SR holes

were not inspected because the P&W engine manual did not specifically reference the SR holes,

the Board examined the manner in which the manual addressed the inspection of the holes in the

disk. The P&W engine manual presents a figure of the 7th stage disk, that shows only 12 holes

(rather than the 24 holes that actually exist) and refers to them as tierod holes; the figure does not

show the 12 SR holes. However, the 24 holes on an actual disk are placed so close together that it

is virtually impossible to inspect tierod holes without noticing the SR holes. Textual material in

the manual does indicate that 0.003-inch damage can be left without blending. However, the

manual also states that no damage can exist in or near any hole. As previously noted, the FAA is

working with P&W to revise P&W’s JT8D engine manual in response to the Board’s Safety

Recommendation A-95-72.

The Safety Board concludes that although the P&W engine manual could have

presented this information in a way that would have made it clearer that the SR holes in the 7th

stage disk had to be inspected and could not contain any damage, the lack of clarity was not a

contributing factor in the failure of the disk because the manual did clearly state that no damage

was permissible in or near any hole.

The Safety Board attempted to determine why a proper inspection was not performed

on the 7th stage disk. In the report of its 1991 shop review of the THY repair facility, P&W

indicated that because the engine manual was written in English, THY should prepare “process

sheets” in Turkish that describe the specific process and repair procedures and actual shop

equipment to be used, and that require signatures of appropriate shop personnel for each

significant step of the procedure as that procedure is completed. P&W indicated such

documentation was not then being used by the THY repair station, and following the 1995 engine

failure, none has been located for the 1991 inspection/overhaul of the 7th stage disk. Further, the

report of the 1991 P&W shop review also pointed out that the job card that purportedly routed the

parts through the FMPI inspection did not specify the process or have a signoff line. Also, the

review indicated that several parts had been tagged with green wires indicating that the parts had

been subjected to an FPI when they could not have received such an inspection, as no residual

fluorescent background material was present on the parts. From this evidence, the Board

concludes that the THY repair station was not using detailed documentation to provide step-bystep guidance at the time of the 1991 overhaul and inspection of the 7th stage disk.

The fact that the disk in this accident had plating over pitting and numerous cracks

suggests that it had not received a proper overhaul or proper inspection for some time. Given that
45

there is no historical evidence that the 7th stage HPC disk of the JT8D has been prone to

developing cracks and ruptures, it is likely that a low or even zero rate of detection of cracks in

this disk would create an expectation that no cracks would be detected. This could lead to

complacency in the inspection process. This potential for complacency in the FPI/FMPI process,

coupled with the failure to detect the crack in this case, raises questions regarding the adequacy of

training procedures for such inspections. The 1991 P&W shop audit noted that THY’s FPI/FMPI

inspectors were trained by one another, and recommended that THY develop a formal training

program or send the inspectors to a nondestructive testing school to become qualified and that they

be retested every 1 to 2 years to ensure that they maintained their practical knowledge and theory.

Because no additional information about THY’s FPI/FMPI training was available for that time

period (1991 and prior), the Safety Board was unable to further investigate or analyze this issue.

However, the adequacy of FPI/FMPI training procedures will be thoroughly investigated and

addressed in the Safety Board’s ongoing investigation of the Delta Air Lines MD-88 uncontained

engine failure in Pensacola, Florida.42

Nonetheless, despite the possibility that there may have been deficiencies in THY’s

training for FPI/FMPI, detailed documentation that specified each individual step in the inspection

and overhaul process and required signatures could have instilled in THY personnel a greater

sense of accountability and increased the likelihood that each step would be accomplished.

Further, if the disk was inspected only on one side, or if it was not inspected at all, it is likely that

detailed documentation that was required to be signed would have increased the likelihood that

these failures would not have occurred. The Safety Board concludes that use of such detailed

documentation would have increased the likelihood that the disk would have received a proper

inspection and that the crack would have been detected; thus, the absence of such detailed

documentation contributed to the accident.

Although detailed documentation would have increased the likelihood of the

performance of a proper inspection, the Board is concerned that because of the dependency on

human performance, a visual inspection, even enhanced (such as an MPI, FMPI, or FPI), may be

an inappropriate inspection procedure when there is a low probability (expectation) of detecting a

crack. The Board is examining this issue in its ongoing investigation of other uncontained engine

failures and will address this issue further in its reports on those investigations.

2.4 Adequacy of FAA Recordkeeping Requirements.

The Safety Board’s review of applicable regulations addressing the type and detail of

records that are required to be retained by all repair stations indicates that FAA guidance in this

area is insufficient and vague. Regulations governing maintenance practices in general (FAR

43.3) require that maintenance record entries contain only “a description (or reference to data

acceptable to the [FAA] Administrator) of work performed.” Regulations governing repair

stations (FAR 145.61) require that repair stations keep “adequate records of all work [that they

do]” but do not define what constitutes “adequate records.” Regulations governing air carrier

 

42 DCA-96-MA-068, MD-88, Pensacola, Florida, 7/6/96.
46

maintenance programs (FAR 121.380) require carriers to keep certain “records” (including records

of the last complete overhaul of each airframe, engine, propeller, rotor, and appliance until the

work is superseded by work of equivalent scope and detail) but do not define what sort of

information, and what degree of detail, those “records” should contain. FAA Order 8130.2C,

paragraph 220, indicates that “necessary maintenance documentation” must accompany an

imported product before it can be returned to service, but there is no definition or clarification in

paragraph 220 of what is considered “necessary maintenance documentation.” Although it is

possible that this is intended to refer to the maintenance records required to be kept by an owner or

operator, as specified in FAR 91.417,43 paragraph 219, “Identification and Marking,” no such

intention is explicitly stated in paragraph 220. In any event, because the records specified in FAR

91.417 are general maintenance records containing only very basic information, they are an

insufficient basis on which to conclude that an item is airworthy, even assuming that is what is

meant by “necessary maintenance documentation.”

Although THY was alerted by P&W in 1991 that the lack of “process sheets” in the

Turkish language represented a deficiency in its operation, it was not until June 1995 that such

documentation (referred to as “traveler forms” by the Director of the THY overhaul shop) was

used by the repair station. Further, although the documentation that the THY repair station began

to use in June 1995 represents a significant improvement, those forms do not contain the level of

detail contained in similar documentation used by some U.S. repair facilities. For example, the

new THY “traveler forms” are generic to any disk and are not specific to any engine; that is, there

is no form specific to the 7th stage HPC disk of a JT8D engine. Further, there is no reference on

the form to specific sections of the engine maintenance manuals (or more detailed job instruction

cards) that describe detailed instructions or references needed to complete the task. This type of

information would not only help to ensure a proper overhaul or prevent a missed inspection, but

would also help to assure the proper application of the overhaul and inspection procedures.

Another advantage to detailed documentation is that, if retained, it provides a much

better basis for verifying the serviceability (or airworthiness) of engines/components being

returned to service. The Safety Board concludes that “process sheets” or similar documentation of

sufficient detail to permit a complete determination of the work needed to be done and of the work

that has been done is necessary for a comprehensive maintenance program to ensure the continued

airworthiness of aircraft, engines, and components. Such a system of documentation could be

described in an advisory circular that sets forth one acceptable method for complying with the

maintenance recordkeeping requirements. Therefore, the Safety Board believes that the FAA

should revise the applicable regulations and provide specific guidance on the documentation to be

used and kept during inspections and overhauls, including “process sheets” or similar detailed

documentation for all certificated repair stations.

 

43 FAR 91.417 requires each owner or operator to keep certain records, including records of maintenance,

alteration, and inspections (including a description of the work performed, the date of completion, and the signature

and certificate number of the person approving the aircraft for return to service); total time in service of airframes,

engines, propellers, and rotors; records showing current status of life-limited parts; time since last overhaul of items

required to be overhauled on a specified time basis; inspection status of the aircraft; status of airworthiness directives,

including method of compliance; and copies of forms required for major alterations.
47

Although foreign repair stations are not subject to the same recordkeeping requirements

as domestic repair stations, the Safety Board recognizes that most repair stations will voluntarily

keep adequate records of work done and believes that the records available in this case met the

minimum standards in existence at this time and were adequate for the consultant to conclude that

the recordkeeping system was valid. Moreover, the Safety Board recognizes that even if THY had

been subject to the same recordkeeping requirements as domestic repair stations, it still would not

have been required to keep records of the 1991 disk overhauls because the engine was installed on

a non-U.S. (Turkish) registered aircraft. Nonetheless, the Safety Board concludes that foreign

repair stations should be subject to at least the same recordkeeping requirements as domestic repair

stations and believes that the FAA should revise 14 CFR Part 145 to require Subpart C foreign

repair stations to adhere to the same recordkeeping requirements of 14 CFR Part 145.61.

2.5 Maintenance Release and “Serviceable” Tags for Aircraft Components

Although the tag on engine SN 666966 described only that the engine had been

preserved for up to 90 days, and FAA regulations state that the signature on a maintenance record

entry constitutes approval for return to service only for the work performed, the technical control

director of THY’s repair station engine shop indicated that THY intended that the tag act as a full

statement of serviceability and release for return to service based on a complete records review,

rather than just the last maintenance action.

The Safety Board is aware that “serviceable” tags are routinely used by industry, vary

considerably in format, and are sometimes relied upon as assurance of overall airworthiness.

However, there appears to be no clear regulatory basis for such an assurance. The Safety Board

concludes that the industry practice of using serviceable tags without a clear understanding of their

purpose can result in the misinterpretation of the intent of these tags. The Safety Board believes

that the FAA should require that “serviceable tags” be used to return engines and other component

parts to service, that they be in a prescribed format (perhaps in the format of FAA Form 8130-3)

and that when there is a change of ownership, and certainly upon importation, the approval for

return to service attest to the overall airworthiness of the part. The tag should reflect that a

complete and thorough review of records, including “process sheets” of the last overhaul, has

taken place. In the absence of such records, an overhaul of the part should be required when there

is a change in ownership.

2.6 THY’s Authority to Overhaul JT8D Engines

The Safety Board received conflicting interpretations of THY’s authority to overhaul

JT8D engines. (Clearly, the engine involved in this accident was not overhauled under U.S.

authority, but under Turkish authority.) In a memorandum dated November 16, 1995, responding

to a Safety Board inquiry, the Director of the FAA’s Flight Standards Service (AFS-1) stated that

THY did not have JT8D engine overhaul authority from 1986-1994. However, THY maintains

that its Air Agency Certificates and associated Repair Station Operations Specifications authorized

THY to overhaul JT8D and other engines during those years.
48

In the Safety Board’s view, the FAA 1986 Repair Station Operations Specifications can

reasonably be read to indicate that THY’s Limited Class 3 powerplant rating (authorizing all levels

of maintenance, including overhaul) permitted overhaul of certain engines, including the JT8D,

and that only line maintenance was authorized for Class 3 engines that were not listed on the

operations specifications.

Because of the Safety Board’s difficulty in understanding the FAA’s contrary

interpretation of this authorization, the Safety Board requested, in a letter to the FAA dated

May 23, 1996, a clarification of the FAA’s position on this issue. In a meeting with Safety Board

staff on July 10, 1996, the FAA reiterated its position that THY did not have authority to overhaul

JT8D engines for U.S.-certificated operations from 1986-1994. The FAA cited a phone call from

THY in 1994 that requested expansion of the operations specifications to include engine

overhauls. The Board remains convinced that the language of THY’s operations specifications

does not readily comport with the FAA’s position, and the Safety Board is concerned that

confusion about the extent of the authority of other repair stations may exist. Thus, the Safety

Board believes that the FAA should review the Air Agency Certificates and Repair Station

Operations Specifications of all repair stations and ensure that language in the operations

specifications clearly indicates the extent of the repair stations' authority.

2.7 Emergency Lighting and Public Address System

When the airplane quickly filled with smoke after the engine failure, the pilots were able

to complete only the first three items on the evacuation checklist before they exited the airplane.

Further attempts by the pilots to complete the checklist could have exposed them to unnecessary

risk. Because the fourth item on the checklist was not completed—moving the emergency light

switch to the “ON” position—emergency lights in the cabin were not illuminated during a portion

of the evacuation. Fortunately, in this accident, the lack of emergency lights in the cabin did not

preclude a successful evacuation.

Several factors affected the timely and successful evacuation. Perhaps the most

important was the ratio of exits to occupants. Six of the seven emergency exits were opened

quickly (two floor-level exits at the front of the cabin and four overwing exits) and used by all 57

passengers. Additionally, the airplane had about half of its full compliment of passengers, and

except for the aft flight attendant, no occupants were injured or incapacitated, which would have

slowed the evacuation. Finally, the cabin interior remained intact and no debris hampered access

to the exits.

The pilot’s first attempt to order an evacuation was not successful because electrical

power to the PA system was lost when the engines were shut down. After the captain selected

emergency electrical power (which caused the emergency lights to turn off), power was restored to

the PA system and the captain successfully communicated the evacuation order. Although the

delay in communicating the evacuation order did not adversely affect the evacuation, this accident

again highlights the need for an independent power source for PA systems in transport-category

airplanes.
49

The Safety Board has issued three safety recommendations over the years advocating an

independent power source for PA systems. The first recommendation (A-74-111) was issued

following a 1974 Safety Board special study44 that examined 10 U.S. carrier accidents in which

emergency evacuations occurred. The Board concluded in that study that PA systems are often

used to initiate emergency evacuations but that they are not always available when aircraft power

is interrupted. From 1974 to 1982, the FAA informed the Safety Board on several occasions that

the issue was being evaluated for consideration in rulemaking action. However, in a letter dated

August 18, 1982, the FAA indicated that it had determined that the cost of compliance with such a

rule would outweigh any identifiable safety benefits. In a letter dated February 14, 1983, the

Safety Board classified Safety Recommendation A-74-111 “Closed—Unacceptable Action.”

In 1979, the Safety Board issued Safety Recommendation A-79-64 as a result of its

investigation of a DC-8 accident in Portland, Oregon.45 The recommendation urged the FAA to

expedite the release of an operations review program notice that contained the 1974

recommendation for an independent power source for the PA system. The FAA subsequently

issued an NPRM that contained the recommendation for an independent power source. Shortly

thereafter, as a result of its investigation of a DC-8 evacuation in Phoenix, Arizona, on

December 29, 1980,46 the Board issued Safety Recommendation A-81-130, urging the FAA to

adopt promptly the rule proposed in the NPRM. The FAA, however, subsequently determined that

the cost of the proposed rule would outweigh the safety benefits and withdrew the NPRM. Safety

Recommendation A-81-130 was therefore classified “Closed—Unacceptable Action.”47

In May 1986, the FAA published an NPRM that would require an independent power

source for PA systems in newly manufactured transport-category airplanes. In its comments on

that rulemaking activity, the Safety Board supported the intent of the proposed rule but noted that

the rule should also provide for the retrofit of all airplanes currently in service. On October 27,

1989, the FAA amended 14 CFR Part 121.318(g) to require that transport-category airplanes

manufactured on or after November 27, 1990, be equipped with an independent power source for

the PA system. The FAA did not include a provision for the retrofit of airplanes currently in

service, as requested by the Safety Board.

Following the accident, the Douglas Aircraft Company modified the evacuation

checklist by placing the activation of the emergency light switch at the beginning of the checklist.

However, the Board is concerned that given the importance of the first three items on the

 

44 National Transportation Safety Board. 1974. Safety Aspects of Emergency Evacuations from Air Carrier

Aircraft. Special Study NTSB/AAS-74/3. Washington, DC.

45 National Transportation Safety Board. 1979. United Airlines, Inc., N80820, Portland, Oregon, December 28,

1978. Aircraft Accident Report NTSB/AAR/79/7.

46 National Transportation Safety Board. 1981. Evacuation of United Airlines DC-8-61, Sky Harbor International

Airport, Phoenix, Arizona.

47 Safety Recommendation A-79-64 had been classified “Closed—Acceptable Action” on April 6, 1981, based on

the FAA’s issuance of an NPRM.
50

checklist, placing the emergency light switch first may not be the safest course of action. Further,

had the PA system had its own independent source of power as the Board has asked for in the past,

then the pilots would not have had to select emergency power, and the emergency lights would

have remained lighted during the evacuation of the airplane.

Communication is vital to a successful evacuation of any transport-category airplane,

regardless of the date of manufacture. This accident again highlights the need for pilots to be able

to communicate with passengers via the PA system without first turning off power to emergency

lights. The Safety Board therefore believes that the FAA should require that all transport-category

aircraft manufactured before November 27, 1990, be retrofitted with a PA system capable of

operating on an independent power source.

2.8 ValuJet’s Flight Attendant Training Program

The investigation of this accident disclosed deficiencies in ValuJet’s flight attendant

training program, including emergency drills training, and the FAA’s inadequate oversight of this

program. Although these deficiencies did not affect occupant survivability in this accident, they

could adversely affect the outcome of future emergency situations.

ValuJet’s flight attendant training program had been approved and the flight attendant

manual had been accepted by the FAA principal operations inspector (POI) for ValuJet in

September 1993. However, contrary to the requirements of 14 CFR Part 121, which require, in

part, that crewmembers operate each type of emergency exit in its normal and emergency modes,

ValuJet’s flight attendant training syllabus did not include hands-on operation of a tailcone release

handle.

The Safety Board has previously addressed this specific issue. Following the ground

collision of a DC-9 and a B-727, and the subsequent fire on the DC-9 at Romulus, Michigan, on

December 3, 1990,48 a flight attendant and a passenger, both of whom died of smoke inhalation,

were found inside the DC-9 tailcone. As a result of its investigation of that accident, the Safety

Board issued Safety Recommendation A-91-6 , which asked the FAA to immediately require

operators of DC-9/MD-80 series airplanes to include in their flightcrew and flight attendant

training programs hands-on training on the operation of the tailcone release handle in

DC-9/MD-80 airplanes using actual airplanes or FAA-approved simulators.

In response to this recommendation, the FAA issued Air Carrier Operations Bulletin

(ACOB) 8-76-6, “Guidelines for Crewmember Training on Aircraft Tailcones and Approval of

Tailcone Training Devices,” on July 13, 1992. The ACOB allowed air carriers to train their

DC-9/MD-80 crewmembers by having an instructor or a trainee operate the tailcone release handle

while other trainees observed. On January 6, 1993, the Safety Board classified Safety

 

48 National Transportation Safety Board. 1991. Northwest Airlines, Inc. Flights 1482 and 299 Runway Incursion

and Collision at Detroit Metropolitan Airport/Wayne County Airport in Romulus, Michigan, on December 3, 1990.

Aircraft Accident Report NTSB/AAR-91/05. Washington, D.C.
51

Recommendation A-91-6 “Closed—Unacceptable Action” because the Safety Board continued to

believe that it was necessary for flightcrews and flight attendants to receive hands-on experience

with every exit that they may be required to operate during an emergency evacuation.

Following this accident, the FAA, on January 26, 1996, issued Flight Standards

Handbook Bulletin No. 96-02, “Guidelines for Crewmember Training on Aircraft Tailcones and

Approval of Tailcone Training Devices.” This bulletin sets forth acceptable means of approving

tailcone training devices and ensures that trainees operate the mechanisms needed to ready the

equipment for emergency evacuation, i.e., “each trainee must actually operate the appropriate

mechanism to ensure evacuation through the tailcone exit.”

As a result of the Safety Board’s accident investigation, ValuJet purchased a tailcone

training device to ensure that flight attendants receive the required training. As of August 31,

1995, all active ValuJet flight attendants had completed the Tailcone Mock-up Drill exercise.

The Safety Board is concerned, however, that the deficiencies in the flight attendant

training program and the flight attendant manual raise serious questions about the adequacy of the

FAA’s review of the program and the manual before approval and acceptance by the FAA in

September 1993. Although the deficiencies noted in this accident were subsequently addressed by

the air carrier, the Safety Board believes that the FAA should emphasize to its POIs the importance

of thoroughly reviewing flight attendant training programs before approving them and manuals

before accepting them.

The investigation revealed that all four overwing exits were opened by passengers

before the aircraft came to a complete stop. This is contrary to the ValuJet flight attendant training

manual, which states that an evacuation should not be initiated until the aircraft has come to a

complete stop. However, there is no indication that the flight attendants would have been able to

prevent the passengers from opening the exit. Although the Safety Board concludes that there

were no negative consequences in this case, the Safety Board is concerned that such premature

actions may adversely affect safety and will continue to monitor this issue.

2.9 In-Lap Children over 2 Years Old

The investigation determined that one child more than 24 months old was listed as a lap

child, despite Federal regulations that require all passengers more than 24 months old to be

restrained during takeoffs and landings. The Safety Board has long been concerned about the

inadequacy and enforcement of this regulation and, in the last several years, has identified at least

six accidents and one enforcement action in which children more than 2 years old were

unrestrained because they were held in someone’s lap. The ages of these children ranged from 26

months to 5 years old.

During the Safety Board’s public hearing following the 1989 DC-10 accident in Sioux

City, Iowa, the Safety Board questioned the Air Transport Association (ATA) about the methods

used by air carriers to ensure that all occupants are properly restrained. The ATA representative

stated that it was “an uncertain art” and that because airlines were a “service industry,” airline
52

representatives would only question a passenger “if they felt that the casual observer could

determine that the child was much larger and probably over two.” According to FAA testimony at

that public hearing, enforcement of this regulation depends on an FAA inspector observing that the

child is more than 2 years old. One inspector discovered a child who was 5 years old being held

on a lap; the inspector initiated enforcement actions.49 The available evidence suggests that the

FAA may only be enforcing this regulation when an egregious violation occurs.

The Safety Board continues to strongly believe that restraints should be available for all

occupants, regardless of age. However, although the Safety Board does not agree with the existing

regulation, until such time as restraints are required for all occupants, the Safety Board believes

that the FAA needs to provide guidance on how to implement its requirement that occupants who

are older than 2 years of age be restrained during takeoffs and landings.

2.10 Notification of Flightcrew of Cabin Fire

Although the right engine fire warning light illuminated, pilots received information that

they had an engine fire from other pilots, and air traffic control personnel asked if emergency

equipment was needed, the most timely and unambiguous information that there was a fire inside

the airplane was provided by the flight attendants. The flight attendants, however, did not follow

ValuJet’s procedure that required the use of the interphone six-chime emergency signal to inform

the cockpit of the fire. Because of the need for a flight attendant to retrieve a cockpit key from its

storage area in the galley before being able to unlock the cockpit door, use of the six-chime signal

would probably have been the faster way to notify the cockpit about the fire. However, the Safety

Board has some concerns regarding the use of the interphone as the sole means of notifying the

cockpit of an onboard fire. In an emergency situation, the cockpit crew may be too busy with other

emergency tasks to immediately answer the interphone. In fact, the Safety Board has investigated

accidents in which the flight attendant’s interphone calls were not answered.50 In this particular

instance, however, it was fortunate that one of the flight attendants had her own cockpit key and

thus was able to quickly notify the flightcrew about the fire.

The Safety Board is concerned that having only one cockpit key available and stored in

the galley may not allow a key to be readily accessible to all flight attendants in an emergency.

Also, relying solely on the six-chime emergency signal to be answered by the flightcrew in the

cockpit when they may be preoccupied with other emergency procedures and tasks could result in

the flightcrew not becoming aware as soon as possible that a fire exists in the cabin. The Safety

Board concludes that all flight attendants should be able to quickly access the cockpit when

appropriate.51 Therefore, the Safety Board believes that the FAA should require that each flight

attendant have a cockpit key in his/her possession at all times while on duty.

 

49 The FAA has advised the Safety Board of only one enforcement action in response to the Safety Board’s

5/29/96 request to the FAA to provide a list of all enforcement actions related to in-lap infants.

50 NYC-86-FA-076, L-1011, Jamaica, New York, 2/15/86; DCA-96-MA-029, B-747, Jamaica, New York,

12/20/95.

51 Subsequent to this accident, ValuJet provided a cockpit key to all of its flight attendants.
53

2.11 Fire Retardant Cabin Furnishings

The aircraft involved in this accident did not meet current regulations regarding

flammability standards for materials used in the interiors of transport-category airplane cabins nor

was it required to do so.

The Safety Board has long been concerned with the FAA’s interpretation that new

standard fire retardant cabin furnishing materials should be only required in the case of a “general

retrofit.” Airplane owners and operators are allowed to continue to perform piece-meal

replacement of cabin furnishings using existing stocks of fire retardant parts that do not meet the

1985 standards. As the regulation is currently worded, an airplane in service for 20 or more years

might never be subject to a “general retrofit.”

During the Safety Board’s investigation of the 1991 runway collision of a B-737 and a

Metroliner at the Los Angeles International Airport,52 it was documented that the B-737, which

was manufactured before the effective date of the FAA 1985 standards, was not required to be, nor

was it, equipped with upgraded fire retardant cabin furnishings. Of the 22 killed on board the B737, 20 succumbed as a result of the inhalation of toxic smoke that was generated by the burning

cabin furnishings.

The Safety Board subsequently issued Safety Recommendation A-91-116, which asked

the FAA to “Prohibit the use, after a specified date, of cabin materials in all transport-category

airplanes that do not comply with the improved fire safety standards contained in 14 CFR 25.853.”

On March 2, 1992, the FAA responded that it had evaluated this safety issue and had determined

that in the case of the Los Angeles accident, it was unlikely that improved materials would have

resulted in improved survivability. The FAA letter further indicated that it was not economically

feasible to implement such a requirement. No further action was taken by the FAA, and the Safety

Board ultimately classified the recommendation “Closed—Unacceptable Action” on September

19, 1994.

On January 6, 1993, the Government Accounting Office (GAO) submitted to the Congress

a report on the status of how the airlines were progressing with installing more fire-resistant cabin

materials in in-service airplanes. 53 The GAO report, stated the following, in part:

In establishing the stricter flammability standards, FAA anticipated that almost 85

percent of the fleet would comply by 2000 and indicated that it would consider

proposing a mandatory retrofit requirement if all airlines did not meet the standards

 

52 National Transportation Safety Board. 1991. Runway Collision of USAir Flight 1493, Boeing 737, and

Skywest Flight 5569, Fairchild Metroliner, Los Angeles International Airport, Los Angeles, California, February 1,

1991. Aircraft Accident Report NTSB/AAR-91/08. Washington, D.C.

53 “Slow Progress in Making Aircraft Cabin Interiors Fireproof” Report to Congressional Requesters. General

Accounting Office, GAO/RCED-93-37, January 6, 1993.
54

as anticipated. At the beginning of 1992, about 11 percent of the over 4,200 aircraft

in the fleet complied with the standards. Although the number of newly

manufactured aircraft meeting the standards will increase each year, no airline has

replaced or plans to completely replace the interior components of aircraft that were

in-service on August 19, 1990 (in service aircraft). As a result, 45 percent of the

aircraft fleet is expected to be operating with cabin interiors not meeting the latest

flammability standards by the end of the decade. In fact, under the current practice

of replacing aircraft, the entire fleet is not expected to comply with the stricter

flammability standards until 2018.

The total cost to the airlines to modify aircraft not meeting the standards would be

several billion dollars and average over $1 million per aircraft. Although costs can

be reliably estimated, more uncertainty exists in reliably estimating the potential

lives saved and their value because airline accidents occur infrequently and

unpredictably, and no consensus exists on the value of a human life. FAA

estimated that 9 to 16 lives could be saved each year if all aircraft met the stricter

flammability standards. If the Department of Transportation’s (DOT) current value

of $1.5 million for a human life were used to extrapolate a value for the potential

fatalities avoided, then up to $110 million could potentially be saved by modifying

aircraft to meet the standards. However, one or two significant accidents could

result in the loss of hundreds of lives and, depending on how high a value was used

for a human life, the potential savings could be much higher.

Almost all aircraft that currently do not meet the flammability standards will

undergo some type of routine heavy maintenance inspection by the end of the

decade, providing airlines the opportunity to modify cabin interiors. However,

airlines infrequently replace entire cabin interiors. Although a portion of the

interior components is removed during a heavy maintenance inspection, airline

officials told GAO that the components not meeting the standards are usually

refurbished and reinstalled, rather than replaced with components that meet the

standards. Industry practice is to replace a worn-out component with one that

meets the standards if it is necessary to purchase a new component. However, this

piecemeal replacement of individual components will likely not significantly reduce

the hazards posed by a post-crash fire.

As a result of its report, the GAO recommended that the Secretary of Transportation direct

the FAA Administrator to reassess whether to issue a regulatory requirement mandating a specific

date for all aircraft in the fleet to comply with the latest flammability standards for cabin interiors.

Such a reassessment should compare the cost-effectiveness of retrofitting aircraft to meet the

standards with other actions that could improve the overall safety of the U.S. aircraft fleet.

In response to this recommendation, the FAA reassessed its earlier cost-benefit analysis

and again concluded that mandatory retrofit of improved cabin materials would not be cost

beneficial, and thus, mandatory retrofit was not warranted.
55

The Safety Board concludes that the ValuJet accident in Atlanta again illustrates the

merit of the Board’s 1991 recommendation. This accident demonstrates the importance of the

current standards and the need for existing aircraft to be brought up to these standards as quickly

as possible. Consequently, the Safety Board believes that the FAA should prohibit the use during

any type of replacement, after 1997, of cabin materials in all transport-category airplanes that do

not comply with the current fire safety standards contained in 14 CFR 25.853. Furthermore, the

FAA should amend 14 CFR Part 121 to prohibit, upon a transfer of the aircraft from one certificate

holder to another, or by January 1, 2001, whichever occurs first, the operation of airplanes with

cabin materials that do not meet the requirements of 14 CFR Part 25.853.

2.12 ValuJet Flight Attendant Uniforms

The FAA provides guidance to airline passengers in a brochure titled, “Fly Smart” (U.S.

Department of Transportation, Federal Aviation Administration, ASP-200, 94/002). This

brochure, among other things, addresses appropriate attire for passengers when flying. The

brochure instructs travelers to wear “sensible” clothing, such as clothes made of natural fabrics,

and recommends long sleeves and trousers that fully cover arms and legs.

The aft flight attendant who received the most serious injuries was wearing shorts and a

short-sleeved shirt. Had she been wearing attire similar to that recommended in “Fly Smart,” she

may not have been burned. Therefore, the Safety Board believes that the FAA should issue an

operations bulletin recommending that POIs advise their air carriers to disseminate FAA safety

guidance on airline passenger attire to their flight attendants.

2.13 Quality of CVR Recording

The recording of the CVR installed on the accident airplane was considered to be a

recording of only fair quality, in that many words were unintelligible, primarily because of the

ambient noise in the cockpit. Although the quality of recording did not affect the determination of

the causal factors in this accident, the Safety Board is concerned that the investigation of future

accidents involving airplanes with similarly equipped CVRs could be impeded by unintelligible

dialogue on the recording. The Safety Board has long been concerned about the quality of CVR

recordings, as reflected in the following safety recommendation, which the Board issued to the

FAA in June 1987:

Amend 14 CFR Parts 23 and 25 to require that all newly manufactured aircraft and

new cockpit voice recorder installations be designed such that an uninterrupted

recording from the boom or mask microphones and headphones for each flight

crewmember’s position and from an area microphone can be made on dedicated

channels of the CVR. On those aircraft requiring only two flight crewmembers, the

unused channel should record the passenger address audio signal when available. A

sidetone shall be produced only when the transmitter or interphone is selected, and,

in addition, all audio signals received by hand-held microphones shall be
56

recorded on the respective crewmember’s channel when keyed to the “ON”

position. (A-87-88) 54

In support of that recommendation, the Safety Board noted in its letter to the FAA that

the Board had found the performance of CVR installations in which the audio signal from the

boom microphone of each flight crewmember is continuously recorded on a dedicated channel,

often referred to as a “hot mic,” to be far superior to the standard cockpit area microphone (CAM),

which is typically mounted on the cockpit overhead panel and picks up ambient noise. A CAM

was installed on the ValuJet accident airplane. The Safety Board reached that conclusion after the

investigation of several accidents/incidents involving both U.S.-registered and foreign-registered

airplanes equipped with CVR “hot mics.”55 The Safety Board stated in its letter to the FAA that,

in fact, the “hot mic” has proven to be a most significant technological improvement in CVRs and

that the level of improvement far surpasses any technological improvement that could be achieved

by state-of-the-art recording or signal processing equipment.

In contrast, the Safety Board noted that the quality of the audio signal recorded by the

standard CAM can generally be described as fair, which requires considerable time and effort to

produce a transcript, and which frequently can result in unintelligible dialogue.

Recent Safety Board accident investigations have continued to highlight the improved

quality in recordings from CVR “hot mics.” 56 These improvements have long been recognized by

other aviation authorities. The Civil Aviation Authority of the United Kingdom has required CVR

“hot mics” since 1974 on all aircraft registered in the United Kingdom. The adoption of CVR “hot

mic” standards (not requirements) by the ICAO and EUROCAE was prompted, in part, by the

United Kingdom’s many years of experience in analyzing CVR “hot mic” recordings.

The Board’s investigation of the ValuJet accident in Atlanta again raises concerns about

the adequacy of CVRs equipped with the standard CAM. Given the numerous benefits of CVR

“hot mics” and the slight cost of these installations, the Safety Board believes that the FAA should

require all airplanes currently required to be installed with a CVR to be retrofitted within 2 years

with a CVR “hot mic.”

 

54 Safety Recommendation A-87-88 was classified “Closed—Acceptable Action” on December 23, 1988,

following rulemaking by the FAA.

55 DCA84IA029--June 23, 1984, Chicago O'Hare Airport; Tradewinds Airways Ltd., Flight 11, Boeing 707, GSAIL; ANC85MA183--September 25,1985, Dutch Harbor, Alaska, Mark Air B737, N674MA; DEN86FA080--

February 20, 1986, Denver, Colorado, Continental Airlines, B737-300; DCA87IA015--December 18, 1986, Simmons

Airlines, Flight 2860, ATR-42, N423MQ.

56 (1) National Transportation Safety Board. 1994. Stall and loss of control on final approach of Atlantic Coast

Airlines, Inc., United Express Flight 6291, Jetstream 4101, N304UE, at Columbus, Ohio, on January 7, 1994. Aircraft

Accident Report NTSB/AAR-94/07. Washington, D.C. (2) National Transportation Safety Board. 1995.

Uncontrolled collision with terrain of Flagship Airlines Inc., doing business as American Eagle Flight 3379, BAe

Jetstream 3201, N918AE, near Morrisville, North Carolina, on December 13, 1994. Aircraft Accident Report

NTSB/AAR-95/07. Washington, D.C.
57

3. CONCLUSIONS

3.1 Findings

1. The flightcrew met the certification, training, and rest requirements of the applicable

Federal regulations before the accident, and the flight attendants had completed ValuJet’s FAAapproved flight attendant training program in existence at the time of the accident.

2. The airplane was certificated and operated in accordance with applicable Federal

regulations.

3. An uncontained failure of the right engine occurred at low airplane and high engine

rotational speed, during the initiation of the takeoff roll. As a result of the uncontained failure,

engine fragments penetrated the airplane’s cabin, severing the right engine main fuel line and

causing the release of pressurized fuel inside the cabin. Sparks that most likely were generated by

steel engine fragments contacting steel galley components ignited a fire that quickly spread

through the airplane’s cabin.

4. The uncontained failure was caused by a fatigue crack in stress redistribution hole “1” in

the 7th stage high compressor disk of engine SN 666966. The fatigue crack length was consistent

with a critical crack length expected to produce separation of the disk under normal operating

conditions.

5. Based on an analysis of fatigue striation measurements, a detectable crack existed in SR

hole “1” in the 7th stage high compressor disk of engine SN 666966 when the disk was overhauled

by the THY repair station in 1991.

6. The 7th stage high compressor disk of engine SN 666966 did not receive a proper

inspection in when the disk was overhauled at the THY repair station in 1991.

7. Had the THY repair station accomplished a proper inspection of the 7th stage high

compressor disk of engine SN 666966, the crack would probably have been detected, the part

rejected, and consequently, the accident might have been avoided.

8. The THY repair station was not using “process sheets” at the time of the 1991 overhaul

and inspection of the 7th stage high compressor disk of engine SN 666966; the use of such

documents would have increased the likelihood that the disk would have received a proper

inspection and that the crack would have been detected.

9. Although the P&W JT8D engine manual could have presented more precise information

in terms of overhaul procedures and instructions, this lack of clarity did not contribute to the

failure of the disk.

10. FAA guidance on what degree of detail is required in maintenance records is

insufficient and vague.
58

11. “Process sheets” or similar documentation of sufficient detail to permit a complete

determination of the work needed to be done and of the work that has been done is necessary for a

comprehensive maintenance program to ensure the continued airworthiness of aircraft, engines,

and components.

12. Foreign repair stations are not, but should be, subject to the same FAA recordkeeping

requirements as domestic repair stations.

13. The industry practice of using serviceable tags without a clear understanding of their

purpose can result in the misinterpretation of the intent of these tags.

14. Although there were conflicting interpretations of THY’s authority to overhaul JT8D

engines by the FAA and THY, the Repair Station Operations Specifications in question can

reasonably be read to indicate that THY did have authority under Part 145 to overhaul JT8D

engines at the time engine SN 666966 was overhauled in 1991.

15. The fourth item on the evacuation checklist was not completed by the flightcrew

because of smoke accumulation in the cockpit; as a result, emergency lights were not available

during a portion of the evacuation. Fortunately, the lack of emergency lights did not preclude a

successful evacuation.

16. Although the pilot’s delay in communicating the evacuation order because of an

electrical power loss did not adversely affect the evacuation, the accident again highlights the need

for an independent power source for public address systems in transport-category airplanes.

17. Although deficiencies in ValuJet’s flight attendant training program, including

emergency drills training, and the FAA’s inadequate oversight of this program did not affect

occupant survivability in this accident, they could have.

18. Although Federal regulations require that all passengers more than 24 months old be

restrained during takeoff and landing, this accident again demonstrates that this regulation is not

always enforced, as one child who was more than 24 months old was listed as a lap child and was

seen being held in an adult passenger’s lap.

19. Because one of the flight attendants had her own key for the cockpit, she was able to

quickly notify the flightcrew about the fire. ValuJet procedures in effect at the time did not

provide for prompt flight attendant access to the cockpit.

20. The aircraft involved in this accident did not meet current regulatory requirements

regarding flammability standards for materials used in the interiors of transport-category airplane

cabins nor was it required to do so. However, this accident demonstrates the importance of the

current standards and the need for existing aircraft to be brought up to these standards as quickly

as possible.
59

3.2 Probable Cause

The National Transportation Safety Board determines that the probable cause of this

accident was the failure of Turk Hava Yollari maintenance and inspection personnel to perform a

proper inspection of a 7th stage high compressor disk, thus allowing the detectable crack to grow to

a length at which the disk ruptured, under normal operating conditions, propelling engine

fragments into the fuselage; the fragments severed the right engine main fuel line, which resulted

in a fire that rapidly engulfed the cabin area. The lack of an adequate recordkeeping system and

the failure to use “process sheets” to document the step-by-step overhaul/inspection procedures

contributed to the failure to detect the crack and, thus, to the accident.
60

4. RECOMMENDATIONS

As a result of this accident investigation, the National Transportation Safety Board

recommends that the Federal Aviation Administration:

Review the Air Agency Certificates and Repair Station Operations

Specifications of all repair stations and ensure that the language used in the

operations specifications clearly indicates the extent of the repair stations’

authority. (Class II, Priority Action)(A-96-78)

Revise 14 CFR Part 145 to require Subpart C foreign repair stations to adhere

to the same recordkeeping requirements as domestic repair stations. (Class II,

Priority Action)(A-96-79)

Revise the applicable regulations and provide specific guidance on the

documentation to be used and kept during inspections and overhauls,

including “process sheets” or similar detailed documentation for all

certificated repair stations. (Class II, Priority Action)(A-96-80)

Require that “serviceable tags” be used to return engines and other

components to service, that they be in a prescribed format (perhaps in the

format of FAA Form 8130-3), and that when there is a change of ownership,

and certainly upon importation, the approval for return to service attest to the

overall airworthiness of the part and the tag reflect that a complete and

thorough review of records, including “process sheets” of the last overhaul,

has taken place. In the absence of such records, require an overhaul of the

part when there is a change in ownership. (Class II, Priority Action)

(A-96-81)

Require that all transport-category aircraft manufactured before

November 27, 1990, be retrofitted with a public address system capable of

operating on an independent power source. (Class II, Priority Action)

(A-96-82)

Emphasize to principal operations inspectors the importance of thoroughly

reviewing flight attendant training programs before approving them and flight

attendant manuals before accepting them. (Class II, Priority Action) (A-96-

83)

Provide guidance on how to implement the requirement that occupants who

are more than 24 months old are restrained during takeoffs, landings, and

during turbulence. (Class II, Priority Action)(A-96-84)

Require that each flight attendant have a cockpit key in his/her possession at

all times while on duty. (Class II, Priority Action)(A-96-85)
61

Prohibit the use during any type of replacement, after 1997, of cabin materials

in all transport-category airplanes that do not comply with the current fire

safety standards contained in 14 CFR 25.853. (Class II, Priority Action) (A96-86)

Amend 14 CFR Part 121 to prohibit, upon a transfer of the aircraft from one

certificate holder to another, or by January 1, 2001, whichever occurs first, the

operation of airplanes with cabin materials that do not meet the requirements

of 14 CFR Part 25.853. (Class II, Priority Action) (A-96-87)

Issue an operations bulletin recommending that principal operations inspectors

advise their air carriers to disseminate Federal Aviation Administration safety

guidance on airline passenger attire to their flight attendants. (Class II, Priority

Action) (A-96-88)

Require all aircraft currently required to be installed with a cockpit voice

recorder (CVR) to be retrofitted within 2 years with a CVR installation designed

such that an uninterrupted recording from the boom or mask microphones and

headphones for each flight crewmember’s position and from an area microphone

can be made on dedicated channels of the CVR. A sidetone shall be produced

only when the transmitter or interphone is selected, and, in addition, all audio

signals received by hand-held microphones shall be recorded on the respective

crewmember’s channel when keyed to the “ON” position. (Class II, Priority

Action) (A-96-89)

BY THE NATIONAL TRANSPORTATION SAFETY BOARD

JAMES E. HALL

Chairman

ROBERT T. FRANCIS II

Vice Chairman

JOHN A. HAMMERSCHMIDT

Member

JOHN J. GOGLIA

Member

GEORGE W. BLACK

Member

August 30, 1996

63

5. APPENDIXES

APPENDIX A - Investigation And Hearing

1. Investigation

The National Transportation Safety Board was initially notified of this accident about

1915 on June 8, 1995, by the FAA. One investigator from the Safety Board’s Southeast Field

Office was immediately dispatched to the scene. A Washington-based team departed for the scene

the following morning. The team consisted of investigative groups in the areas of Operations,

Structures/Systems, Performance, Materials, Powerplants, Survival Factors, and

Maintenance/Records.

Parties to the investigation were the FAA, ValuJet, the Douglas Aircraft Company, Pratt

& Whitney, and the Association of Flight Attendants.

2. Hearing

No public hearing was held in connection with this accident investigation.

65

APPENDIX B - CVR Transcript
66

NATIONAL TRANSPORTATION SAFETY BOARD

Engineering & Computer Services Division

Washington, D.C. 20594

SPECIALIST’S FACTUAL REPORT OF INVESTIGATION

Cockpit Voice Recorder

by

Albert G. Reitan

Transportation Safety Specialist

Warning

The reader of this report is cautioned that the transcription of a CVR tape is not a

precise science but is the best product possible from an NTSB group investigative

effort. The transcript, or parts thereof, if taken out of context, could be misleading. The

attached CVR transcript should be viewed as an accident investigation tool to be used

in conjunction with other evidence gathered during the investigation. Conclusions or

interpretations should not be made using the transcript as the sole source of

information.
67

NATIONAL TRANSPORTATION SAFETY BOARD

Engineering & Computer Services Division

Washington, D.C. 20594

SPECIALIST’S FACTUAL REPORT OF INVESTIGATION

Cockpit Voice Recorder

ATL 95 MA 106

June 20,1995

A. ACCIDENT

Location: Atlanta Hartsfield Airport - Atlanta, Georgia

Date: June 8, 1995

Time: 1908 Eastern Daylight Time (EDT)

Aircraft: DC-9-32, N908VJ

B. GROUP

Chairman: Albert G. Reitan

Transportation Safety Specialist (CVR)

National Transportation Safety Board

Member: Martin H. (Hop) Potter

Aviation Safety Inspector

Federal Aviation Administration

Member: Webster C. Heath

Manager Tecchnical Liaison Industry Regulatory Affairs

McDonnell Douglas

Member: Paul D. Weston

Captain

ValuJet

Member: Bruce A. Samborski

Airworthiness Engineer

United Technologies, Pratt & Whitney
68

C. SUMMARY

A Fairchild model A-100A cockpit voice recorder (CVR), s/n 53333, was

brought to the audio laboratory of the National Transportation Safety Board on

June 9, 1995. The Cockpit Voice Recorder committee convened on June 13,

1995. A transcript was prepared of the entire 31:16 minute recording.

(attached)

D. DETAILS OF INVESTIGATION

The exterior of the CVR showed no evidence of structural damage. It was

covered with a light coating of soot. The interior of the recorder and the tape

sustained no apparent heat or impact damage.

The recording consisted of three channels of fair quality audio information.

The area microphone channel contained a large amount of background noise so

the pilot voices were read only with great difficulty. A second channel contained

information from the pilots’ audio panels and a third contained the interphone

and public address information.

The recording started at 1838:03 EDT and continued uninterrupted except

for a one second interval until 1908:20 EDT when electrical power was removed

from the unit. When the recording started, the flight was at the gate preparing

for departure. The recording continued as the crew prepared for departure and

taxied to the departure runway. The recording ended when the aircraft stopped

on the runway after experiencing an engine problem.

As part of the Safety Board’s accident investigation process, the cockpit

flightcrew was invited to review the CVR group’s transcript and suggest

corrections or additions. The captain and first officer reviewed the CVR

recording and transcript on June 28, 1995, and suggested the following

changes:
69

Page 15

1902:42 {25:37}

CAM-1 flaps five, before takeoff check list.

Page 16

1902:56 {25:51}

CAM-2 performance data and bugs?

1903:51 {26:46}

CAM-1 set and, ** ANU.

1904:50 {27:45}

CAM-1 five flaps, one thirty uh, climb to ten thousand feet, heading 

whatever they give us, * nine five.

1905:45 {28:40}

CAM-1 hey Meg.

Page 17

1905:51 {28:46}

CAM-1 * the mark of a true professional if you can keep talking like that.

Page 18

1907:54 {30:49}

CAM-? alright, here, they’re spooled .

 Albert G. Reitan

Transportation Safety Specialist (CVR)

Attachment:
70

Transcript of a Fairchild A-100A cockpit voice recorder (CVR), s/n 53333,

installed on an Douglas DC-9-32, N908VJ, which was which sustained an engine

failure during takeoff from Atlanta Hartsfield International Airport on June 8, 1995

LEGEND

RDO Radio transmission from accident aircraft

CAM Cockpit area microphone voice or sound source

INT Transmissions over aircraft interphone system

ATIS Radio transmission from Atlanta Departure ATIS

GND Transmission received from Atlanta south ground control

TWR Transmission received from Atlanta tower

PA Transmission made over airacraft public address system

CLR Radio transmission from Atlanta clearance delivery

TR-? Radio transmission from unidentified aircraft

-1 Voice identified as Pilot-in-Command (PIC)

-2 Voice identified as Co-Pilot

-3 Voice identified as 1st female Flight Attendant

-4 Voice identified as 2nd female Flight Attendant

-5 Voice identified as female ground agent

-6 Voice identified as male ground agent

-? Voice unidentified

* Unintelligible word

@ Non pertinent word

# Expletive

% Break in continuity

( ) Questionable insertion

[ ] Editorial insertion

.... Pause

Note: Times are expressed in eastern daylight time (EDT).

Times shown in brackets { } are computer reference times measured from the beginning of the recording.
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENTSTART of RECORDINGSTART of TRANSCRIPT1838:03 {00:58}CAM-6 gentlemen, any write ups?1838:04 {00:59}CAM-2 actually our uh, transponder, TCAS fail light stays on.1838:11 {01:06}CAM-6 fail light stays on?1838:12 {01:07}CAM-2 yeah. so we don't get any contacts or anything that it's working.1838:20 {01:15}CAM-6 Mar* Mike, Mar* Mike.1838:23 {01:18}CAM-2 captain, do you want to write it up *?1838:25 {01:20}CAM-? **.1838:27 {01:22}CAM-6 anything you want to write up?1838:27 {01:22}CAM-1 no.1838:29 {01:24}CAM-6 you wanna wait till you get back?1838:31 {01:26}CAM-1 yeah, we're running late.
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1838:35 {01:30}CAM-1 depends on how long we're going to take.1838:36 {01:31}CAM-6 we're gonna have to bring avionics guy out here and uh.1838:40 {01:35}CAM-? and uh,1838:46 {01:41}CAM-2   radar altimeter may have something to do with it.1838:50 {01:45}CAM-1 the altimeter, yeah.1838:53 {01:48}CAM-6 if you want it fixed, I'll call 'em out here, you know, that's up to

you.

1838:57 {01:52}CAM-2 he he did not want to write it up.1838:58 {01:53}CAM-6 he didn't?1838:59 {01:54}CAM-2 no.1839:00 {01:55}CAM-6 he gonna write it back up on the way in.1839:02 {01:57}CAM-2 we will do that.1839:03 {01:58}CAM-6 OK, alright, we just don't think ** ** pin it on us.
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1839:35 {02:30}CAM [sound of non pertinent flight attendant conversation in background]

1839:35 {02:30}ATIS this is the Atlanta departure inform

lanta two one five zero zulu weatthousand five hundred scattered, perature niner four, dew point sevzero at seven, altimeter two niner ous departures in progress. depaleft and two seven right. aircraft wareas, expect runway two six lefteast vector areas expect runway receipt of your ATC clearance, resign and transponder code unlesadvise on initial contact, you have 

1842:38 {05:33}CAM-2 hi, how you doing?1842:40 {05:35}CAM-3 ***** please gentlemen.1842:42 {05:37}CAM [several unintelligible flight attendant pilot comments]1843:13 {06:08}CAM-3 what time are we gonna get home now, eleven?1843:16 {06:11}CAM-2 let's see. we're supposed to get home at nine thirty five. that's

taking off at five thirty five. ** four hours.

1843:34 {06:29}CAM-3 two hours (late, we'll get in at   eleven thirty ** **).
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1843:41 {06:36}CAM-2 OK, is that it now?1843:42 {06:37}CAM-4 we're still waiting on catering.1843:44 {06:39}CAM-2 OK,1843:45 {06:40}CAM-? ** eighteen1843:46 {06:41}CAM-2 OK. *****.1843:48 {06:43}CAM-2 yeah, thirty five.1843:52 {06:47}CAM-? [sound of laughter]1844:00 {06:55}CAM-1 ninety three, I'll tell you what, the temperature wasn't much

different down there.

1844:03 {06:58}CAM-2 oh yeah.1844:56 {07:51}CAM [bell sound similar seat belt chime]1844:57 {07:52}CAM-1 well.1844:59 {07:54}CAM-1 what did they finally decide? are we taking folks with us to

several cities or just Miami?
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1845:07 {08:02}CAM-? I think it's Miami. ***** thirty five ** thirty nine.1845:19 {08:14}CAM-1 have we called 'em a couple of times already?1845:23 {08:18}CAM-5 I haven't done anything.1845:27 {08:22}CAM-1 you talked to them at all about catering?1845:28 {08:23}CAM-2 no. that's the first I've heard.1845:30 {08:25}CAM-1 OK.1845:31 {08:26}PA-3 Good evening ladies and gentlemen. we would like to welcome you aboard ValuJet's flight five ninety seven now nonstop service to Miami. as you are getting comfortably seated,

we do need to remind you that every bit of the carry-on luggage you brought on board, needs to either go underneath theseat in front of you or in one of the overhead compartments. Ifyou need any assistance with your luggage, please let one ofus know at this time. in addition federal regulations require allpassengers seated in emergency exit rows fourteen, fifteen,and sixteen, to be responsible for these exits and for assistingothers in the event of an emergency. if you are unable or donot wish to perform these emergency duties, please let Deniseknow at this time, she'll be happy to change you to anotherseat. just a reminder, this is a non smoking flight. your compliance is required by federal aviation regulations. Thank youfor your attention and welcome aboard.
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT

1846:22 {09:17}RDO-1 and uh, Critter one forty seven, o

mation Tango ur uh, one forty se

1846:29 {09:24}CLR Critter one forty seven, I don't se

here. no what time are you due o

1846:35 {09:30}RDO-1 no, I got my numbers wrong. it's 

ami. due out at uh, five thirty five 

1846:40 {09:35}CLR five ninety seven, we do have tha

what was your ramp?

1846:44 {09:39}RDO-1 four.1846:50 {09:45}CLR Critter five ninety seven, OK, clea

Atlanta three departure. Maintain departure on one twenty five zerothree three. south side number oground on point seventy five.

1847:04 {09:59}RDO-1 seventy one thirty three. thank y1847:07 {10:02}CLR OK.

1847:17 {10:12}CAM-2 (one) thirty three.1847:20 {10:15}CAM-3 they get these from you? up there?
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1847:22 {10:17}CAM-? *** we checked *****.1847:27 {10:22}CAM-3 alright.1847:33 {10:28}CAM [several unintelligible comments between pilots and flight attendants]1848:11 {11:06}CAM-1 tell her we're about to ***** you want to write it up ******.1848:50 {11:45}CAM-? count thirty three and twenty four right now. thirty three up

front twenty four in the back.

1849:08 {12:03}PA-1 folks good evening and welcome aboard. I'm Greg Straessle

your captain along with your co-captain Steve Rasin. Rachel,Magen, and Denise in the back to take good care of you. it's aone hour nineteen minute flight down to Miami, Florida. w'betaking out of here very shortly heading on down there scatteredclouds, a little cooler in Miami than it is here, actually. it'sninety three degrees in Miami, ninety four here at about tenknots of wind down there. seat belt sign's on if you wouldplease uh, observe that and fasten 'em up snugly. we'll be under way very, very shortly here uh, we apologize for the delay.it started a while back uh, with a little bit of a maintenanceproblem that was cured but just took a little longer than wewanted it to to progress and finally get fixed. so as I say we'llbe under way shortly and get you there as soon as we can.thank you for joining us today.

1850:01 {12:56}CAM [unintelligible conversation overridden by nearby jet engine

noise]
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1850:41 {13:36}CAM-1 ***** ninety nine?1850:46 {13:41}CAM [more unintelligible conversation]1852:33 {15:28}CAM-3 there's **.1852:53 {15:48}CAM-5 hello.1852:54 {15:49}CAM-? hi, how ya doing?1852:56 {15:51}CAM-5 we got two hundred and ten pounds in the hold in the front. we

got fifty bags in the rear, and ten bags in the front. going outsouthbound? take the power off and raise the stairs?

1853:13 {16:08}CAM-2 yeah, you sure can.1853:14 {16:09}CAM-5 alright, and the stairs and hydraulics on?1853:16 {16:11}CAM-2 yep it's on.1853:16 {16:11}CAM-5 alright, thank you.1854:12 {17:07}CAM-? what are they **.1854:13 {17:08}CAM-2 uuuh.
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1854:17 {17:12}CAM-? not them.1856:53 {19:48}CAM-5 catering guy. ** you ready?1856:55 {19:50}CAM-? we're ready.1856:58 {19:53}CAM-5 OK, see you later.1857:06 {20:01}CAM-5 what time are you guys goin' out?1857:08 {20:03}CAM-1 uuuuh, fifty five, what do you want?1857:10 {20:05}CAM-5 OK, that sounds good.1857:18 {20:13}CAM-1 soon as they close the cargo door.1857:26 {20:21}CAM-3 everybody's down.1857:31 {20:26}PA-3 flight attendants prepare for departure please, cross check.1857:57 {20:52}CAM [sound of two dings]1858:06 {21:01}CAM-? ninety four ***.1858:12 {21:07}CAM [sound of single ding]
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1858:15 {21:10}CAM-1 ***** starting engines check list. OK.1858:41 {21:36}CAM-1 starting two, lets go below the line please.1858:43 {21:38}CAM-2 clearance to start?1858:43 {21:38}CAM-1 received.1858:44 {21:39}CAM-2 shoulder harness? on.1858:45 {21:40}CAM-1 comin' on.1858:46 {21:41}CAM-2 parking brakes?1858:46 {21:41}CAM-1 they're set.1858:47 {21:42}CAM-2 fuel quantity? twenty four one.1858:48 {21:43}CAM-1 I see it, rechecked. twenty four plus.1858:51 {21:46}CAM-2 pneumatic crossfeeds?1858:52 {21:47}CAM-1 are open.
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1858:52 {21:47}CAM-2 anti-collision lights?1858:53 {21:48}CAM-1 on.1858:54 {21:49}CAM-2 air conditioning supply switches?1858:54 {21:49}CAM-1 off.1858:55 {21:50}CAM-2 fuel boost pumps?1858:56 {21:51}CAM-1 on.1858:56 {21:51}CAM-2 ignition?1858:58 {21:53}CAM-1 comin' on right side, that **.1859:08 {22:03}CAM-1 oil,1859:09 {22:04}CAM-1

N2,

1859:12 {22:07}CAM-1

N1,

1859:15 {22:10}CAM [sound of click]1859:16 {22:11}CAM-1 fuel.
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1859:21 {22:16}CAM [sound similar to engine increasing in frequency]1859:28 {22:23}CAM-1 ** cut out, slower start, acceleration **, on the line.1859:40 {22:35}CAM-1 oil,1859:42 {22:37}CAM-3 uh,1859:51 {22:46}CAM-1 fuel1859:52 {22:47}CAM [sound similar to engine increasing in frequency]1900:01 {22:56}CAM [sound of two dings]1900:05 {23:00}CAM-2 electrical panel?1900:06 {23:01}CAM-1 set.1900:06 {23:01}CAM-2 ignition?1900:07 {23:02}CAM-1 off.1900:07 {23:02}CAM-2 pitot static heat?
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1900:08 {23:03}CAM-1 on.1900:08 {23:03}CAM-2 ice protection?1900:09 {23:04}CAM-1 off.1900:09 {23:04}CAM-2 center tank pumps?1900:10 {23:05}CAM-1 on.1900:10 {23:05}CAM-2 flight attendant signal?1900:11 {23:06}CAM-1 given.1900:12 {23:07}CAM-2 air conditioning?1900:12 {23:07}CAM-1 auto.1900:13 {23:08}CAM-2 door lights?1900:13 {23:08}CAM-1 out.1900:14 {23:09}CAM-2 hydraulic pumps?1900:15 {23:10}CAM-1 set.
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1900:19 {23:14}CAM [several unintelligible comments overridden by loud engine

noise]

1901:03 {23:58}CAM-2 clear on the right.1901:30 {24:25}PA-3 once again good evening ladies and gentlemen. we would like

to welcome you aboard ValuJet's flight 597 now non-stopservice to down to Miami. on the flight deck is captain GregStraessle. he's assisted by first officer Steve Rasin. my nameis Megan. working along with me this evening are Rachel andDenise. your flight attendants are one of the most importantsafety features of this aircraft. we do ask for your attention forjust a few minutes as we go over some very important information with you. we do request that you please read the safetyinformation card located in the seat pocket in front of you as weexplain the safety features of our DC-9-32 aircraft. at this timeDenise and Rachel will demonstrate the easy operation of yourseat belt. first insert the flat metal end into the buckle. to adjust pull on the loose strap. to release simply lift up on thebuckle. seat belts should always be fastened when the seatbelt sign is illuminated. on this particular aircraft there arethree door exits, two at the front of the aircraft and the tail coneexit at the rear of the aircraft. all door exits are equipped withevacuation slides. in addition there are four window exits, twoover each wing. all exits are clearly marked to assist you in locating them. there is also a lighting system in the floor whichwill illuminate in an emergency. red lights indicate you havereached or are near an exit. the cabin is pressurized for yourcomfort, however if oxygen is needed an oxygen panel willdrop from a compartment above your seat. you would reachup and pull down on the mask until the tubing is fully extended.place the mask over your nose and mouth, secure it with the
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT

elastic band, and breath normally. the oxygen bag may notappear to inflate, however oxygen is flowing. for those of youtraveling with small children please adjust your mask first andthen assist your child. the passenger seat cushions on thisaircraft can be used as flotation equipment. detailed instructions on its use are found on the back side of the safety instruction card. smoking is not permitted at any time on boardour aircraft. federal law prohibits tampering with the smokedetectors that are in our aircraft lavatories. your compliancewith crewmembers' instructions, all placards, lighted seat beltand no smoking signs is required. also please keep in mindthat due to possible interference with our navigational systemsthe following electronic devices may not be used during takeoffand landing: portable compact disk players, portable computers, and cellular phones should now be in the off position andstowed. in preparation for our takeoff this evening please double check and make sure your seat belts are securely fastenedaround you. please bring your tray tables and seat backs tothe their full upright and locked position, and all carry on luggage should be underneath the seat in front of you completely,or in one of the overhead bins. the captain has informed methat our flying time down to Miami will be one hour and nineteen minutes. we sincerely do appreciate your attention, andwelcome aboard.

1902:25 {25:20}RDO-2 Atlanta ground, Critter five ninety 

south with Tango.

1902:31 {25:26}GND Critter five ninety seven Atlanta g

two seven right via Mike.

1902:34 {25:29}RDO-2 two seven right via Mike, Critter f
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1902:42 {25:37}CAM-1 flaps five *** check list.1902:43 {25:38}CAM-2 flaps five.1902:56 {25:51}CAM-2 data and bugs?1902:57 {25:52}CAM-1 alright I see *** do you agree?1903:49 {26:44}CAM-2 trim controls?1903:51 {26:46}CAM-1 set and,1903:55 {26:50}CAM [sound similar to stabilizer trim in motion]1904:15 {27:10}CAM-1 set and six.1904:18 {27:13}CAM [unintelligible conversation between pilot and flight attendant]1904:45 {27:40}CAM-1 looks like we're gonna get right outta here.1904:50 {27:45}CAM-1 five flaps, one thirty uh, ten thousand feet, heading whatever

they give us, * nine five.

1905:22 {28:17}CAM [several unintelligible comments between pilots]
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1905:45 {28:40}CAM-2 hey Meg.1905:50 {28:45}CAM-3 what, yes sir.1905:51 {28:46}CAM-2 * the mark of a true faithful if you can keep talking like that.

1906:02 {28:57}TWR Critter five ninety seven Atlanta to

right, taxi into position and hold.

1906:04 {28:59}RDO-2 position and hold two seven right

seven.

1906:09 {29:04}PA-2 flight attendants take your seats for departure.1906:21 {29:16}CAM-2 anti-skid?1906:22 {29:17}CAM-1 yep.1906:29 {29:24}CAM-2 cockpit door? locked.1906:30 {29:25}CAM-2 ignition? on.1906:30 {29:25}CAM-2 APU? off.1906:31 {29:26}CAM-2 flight attendant signal? given.
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT1906:32 {29:27}CAM-2 anti-skid? is armed.1906:33 {29:28}CAM-2 TCAS transponder? TA RA.1906:34 {29:29}CAM-2 pneumatic cross-feeds? closed.1906:35 {29:30}CAM-2 annunciator panel? checked.1906:36 {29:31}CAM-2 takeoff briefing? accomplished. before takeoff checklist complete.

1907:34 {30:29}TWR Critter five ninety seven middle m

two five zero, runway two seven 

1907:39 {30:34}RDO-2 two five zero at the marker, clear

right, Critter five ninety seven.

1907:45 {30:40}CAM [sound similar to increase in engine RPM]1907:54 {30:49}CAM-? * here * .1907:58 {30:53}CAM [one second interruption in CVR audio]1907:58 {30:53}CAM [repetitive thumping sounds lasting for three seconds]

1908:00 {30:55}
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATI

TIME & TIME &SOURCE CONTENT SOURCE CONTENT

TR-? ValuJet rolling on the runway you 

gine.

1908:02 {30:57RDO-2 Critter five ninety seven understa

right engine. we'll be stopping he

1908:06 {31:01}TWR five ninety seven roger, do you n

1908:08 {31:03}CAM-3 **.1908:08 {31:03}CAM-1 OK.1908:09 {31:04}CAM-1 yes, roll the equipment.

1908:10 {31:05}RDO-2 affirmative, roll the equipment, ro

1908:10 {31:05}CAM [sound of commotion from passenger cabin]1908:15 {31:10}PA-3 flight attendant, ladies and gentlemen, please wait until the

plane comes, ladies.

1908:20 {31:15}CAM [sound similar to engine decreasing in RPM]1908:21 {31:16}END of RECORDINGEND of TRANSCRIPT
INTRA-COCKPIT COMMUNICATION AIR-GROUND COMMUNICATION

TIME & TIME &

SOURCE CONTENT SOURCE 

1908:08 {31:03}

CAM-3 **.

1908:08 {31:03}

CAM-1 OK.

1908:09 {31:04}

CAM-1 yes, roll the equipment.

1908:10 {31:05}

RDO-2 affirmative, roll the equipment, roll the equipment.

1908:10 {31:05}

CAM [sound of commotion from passenger cabin]

1908:15 {31:10}

PA-3 flight attendant, ladies and gentlemen, please wait until the

plane comes, ladies.

1908:20 {31:15}

CAM [sound similar to engine decreasing in RPM]

1908:21 {31:16}

END of RECORDING

END of TRANSCRIPT

90



































126

APPENDIX F - Examples of ValuJet’s Flight Attendant Manual Emergency Equipment—

Before and After Revision in November 11, 1995

FLIGH T ATTENDANT MANUAL

Page: 2-9

Date: 1/13/94

Revision: 1
127

VALUJET Page: 3-19

 Date: 11/11/95

FLIGHT ATTENDANT MANUAL Revision: 5

3.21 LOCATION OF EQUIPMENT ON AIRCRAFT

3.21.1 A/C #901 -907,909-923,965

FWD. OVERHEAD BIN

A/C LEFT

OVERWING

AFT OVERHEAD BIN

A/C LEFT

AFT JUMPSEAT AREA

am

I

I

L

I

OVERWING

AFT OVERHEAD BIN

A/C RIGHT
128

APPENDIX G - Comparison of Requirements for Domestic and Foreign Repair Stations

Certificated Under FAR Part 145

DOMESTIC FOREIGN

Ratings . Ratings are issued for “classes” of . Same as Domestic

items within the following

categories: Airframe, Powerplant,

Propeller, Radio, Instrument, and

Accessory. [Example: a “Class 2“

Powerplant rating authorizes the

repair station to work on

reciprocating engines of more than

400 horsepower; a “Class 3“

Powerplant rating authorizes the

repair station to work on Turbine

engines. ]

(145.31)

. Limited ratings maybe issued for

a particular make or model within

a class of airframe, powerplant,

propeller, radio, instrument or

accessory, or for other specialized

services.

(145.33).

Housing and facility ● Must provide suitable housing, ● Same as Domestic.

requirements space, and facilities to protect

work and workers. Detailed

requirements for segregation of

equipment and functions,

appropriately organized storage

areas, lighting requirements, etc.

(145.35)

● Additional requirements for

housing of airframes, suitable

means for segregating engines or

accessory assemblies, storage of

propellers, and protection of radio

and instrument parts,

(145,37)
129

 DOMESTIC FOREIGN

Inspection systems • Must have an inspection system

that will produce satisfactory

quality control. Detailed

requirements for qualifications of

inspection personnel. Detailed

requirements for inspection

systems. Must maintain a manual

containing inspection procedures.

(145.45)

• Same as Domestic.

Equipment and materials • Must have equipment and

materials necessary to competently

and efficiently perform functions

appropriate to the ratings and

classes sought. Detailed and

specific requirements are set forth.

(145.47 and .49)

• Same as Domestic.

Performance standards • Must abide by maintenance

regulations in FAR Part 43. Must

maintain manufacturers manuals,

instructions, and bulletins.

• Same as Domestic.

Work for Part 121

operators

• Must abide by requirements of

carrier’s continuing airworthiness

program, and work must be in

accordance with carrier’s manual.

(145.2)

• Same as Domestic.

Inspection of work

performed

• Before approving an item for

return to service, must be

inspected by qualified inspector

and must certify on maintenance

record that it is airworthy with

respect to the work performed.

(145.49)

• Same as Domestic.

Inspection by FAA • Must allow FAA to inspect (for

adequacy of inspection system,

records, and general ability to

comply with Part 145) at any time.

FAA will notify repair station of

defects found.

(145.23)

• Same as Domestic.
130

 DOMESTIC FOREIGN

Issuance of Certificate • Application must include copy of

inspection procedures manual, and

list of maintenance functions to be

“contracted out”.

• Applicant who meets requirements

of Part 145 is “entitled” to a

certificate.

(145.11)

• In addition to

information required

by 145.11, must

submit brochure

describing facilities,

inspection system,

organizational chart,

names/titles of

supervisory

personnel, and list of

functions to be

“contracted out” and

contractor names.

(145.13)

• Applicant must also

show that the

certificate “will be

necessary for

maintaining U.S.

registered aircraft or

parts.

(145.71)

Duration of Certificate • Does not have to be renewed.

(145.17)

• Must be renewed

within 12 months of

initial issuance, and

every 24 months

thereafter.

(145.17)

Privileges of certificate • May maintain/alter and approve

for return to service any aircraft or

part for which it is rated.

(145.51)

• Same as domestic,

but limited to U.S.

registered aircraft or

parts.

(145.73)
131

 DOMESTIC FOREIGN

Personnel requirements

(including certification)

• Must have enough personnel to

keep up with volume of work.

• All supervisory and inspection

personnel must be FAA-certified

as mechanics or repairmen.

• Personnel directly in charge of

maintenance functions must have

18 months of practical experience

in the applicable procedures.

• For each rating, must have

employees with detailed

knowledge of applicable

maintenance functions/techniques

based on attending factory school

or long experience.

• Must document and update work

history and experience of all

supervisory and inspection

personnel.

 (145.39, .41 and .43)

• Must have enough

personnel to keep up

with volume of

work.

• No personnel are

required to have

FAA (or any)

certification .

• Supervisors and

inspectors must be

able to read, write,

and understand

English, and must

show they

understand the

FARS and

manufacturer’s

instructions.

(145.75)

Record-keeping • Must maintain “adequate records

of all work that it does,” including

names of mechanics and

inspectors, for 2 years.

(145.61)

• Exempt from

145.61.

• But must maintain

records of all

maintenance/alterati

on done on U.S

registered aircraft

[no time period

specified], and any

other records the

FAA “finds

necessary.”

(145.79)

Reports of unairworthy

conditions

• Must report defects and

unairworthy conditions to FAA

within 72 hours of discovery.

(145.63)

• Same as Domestic,

but reporting

requirement only

applies to U.S.

registered aircraft.

(145.79)