This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents. Prices of

new books are listed in the first FEDERAL

REGISTER issue of each week.

Rules and Regulations Federal Register

11611

Vol. 60, No. 41

Thursday, March 2, 1995

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95–SW–12–AD; Amendment

39–9165; AD 95–04–13]

Airworthiness Directives; Robinson

Helicopter Company Model R44

Helicopters

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to Robinson Helicopter

Company Model R44 helicopters, that

currently requires revisions to the

Limitations section, the Normal

Procedures section, and the Emergency

Procedures section of the R44 Rotorcraft

Flight Manual, revised September 6,

1994. These revisions limit operations

in high winds and turbulence; provide

information about main rotor (M/R)

stalls and mast bumping; and provide

recommendations for avoiding these

situations. Additionally, emergency

procedures are provided for use should

certain conditions be encountered. This

amendment requires the same revisions

required by the existing Priority Letter

AD, but revises certain words and

phrases to further clarify the revised

Limitations and Normal Procedures

sections, deletes the paragraph that

referenced recording compliance with

the AD, and adds another paragraph that

states that no special flight permits will

be issued prior to compliance with this

AD. This amendment is prompted by

two Model R44 accidents since April

1994 involving M/R blades contacting

the helicopters’ fuselage; and, 26

accidents involving M/R blades

contacting the fuselage on the Model

R22 helicopter since 1981. The Model

R22 helicopter M/R system design is

similar to the Model R44 helicopter M/

R system design. The actions specified

by this AD are intended to prevent M/

R stall or mast bumping, which could

result in the M/R blades contacting the

fuselage causing failure of the M/R

system and subsequent loss of control of

the helicopter.

DATES: Effective March 17, 1995.

Comments for inclusion in the Rules

Docket must be received on or before

May 1, 1995.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Office of the

Assistant Chief Counsel, Attention:

Rules Docket No. 95–SW–12–AD, 2601

Meacham Blvd., Room 663, Fort Worth,

Texas 76137.

FOR FURTHER INFORMATION CONTACT: Mr.

Scott Horn, Aerospace Engineer, FAA,

Rotorcraft Directorate, Rotorcraft

Standards Staff, Southwest Region, 2601

Meacham Blvd., Fort Worth, Texas

76137, telephone (817) 222–5125, fax

(817) 222–5961.

SUPPLEMENTARY INFORMATION: On

January 12, 1995, the FAA issued

Priority Letter AD 95–02–04, to require

revisions to the Limitations section, the

Normal Procedures section, and the

Emergency Procedures section of the

R44 Rotorcraft Flight Manual, revised

September 6, 1994. These revisions

limit operations in high winds,

turbulence, and wind shear conditions;

provide information about M/R stalls

and mast bumping; and, provide

recommendations for avoiding these

situations. That action was prompted by

two Model R44 accidents since April

1994 involving M/R blades contacting

the helicopters’ fuselage. M/R stall and

mast bumping may have caused these

M/R blade contacts with the fuselage.

Both of these accidents resulted in

fatalities. Limited pilot experience in

rotorcraft has been identified as

common to these accidents. High winds

and turbulence were also noted in both

of the accidents. Airspeed and low rotor

RPM could also be influencing factors in

these M/R blades contacting the

fuselage. Flight in strong or gusty winds,

areas of wind shear, or areas of

moderate, severe, or extreme turbulence

can degrade the helicopter handling

qualities, thereby creating an unsafe

condition. These conditions, if not

compensated for, could result in M/R

stall or mast bumping, which could

result in the M/R blades contacting the

fuselage causing failure of the M/R

system and subsequent loss of control of

the helicopter.

Since the issuance of that AD, the

FAA has determined that the words

‘‘areas of forecasted or reported’’ should

be deleted from the revision to the

Limitations section of the Model R44

Rotorcraft Flight Manual, revised

September 6, 1994. Some operators

receive area forecasts and reports that

cover wide geographic regions. These

forecasts and reports can refer to

turbulence in areas unrelated to the

actual area of operation. Forecasted or

reported wind shear or turbulence

outside of the operational area was not

intended to be a flight limitation. The

word ‘‘spreads’’ was added to the term

‘‘wind gusts’’ to define this limitation as

the spread or variance of wind

velocities. The phrase ‘‘but no lower

than 60 knots’’ was added to the

Limitations section because of the

possibility that at higher altitudes, 0.7

Vne could be lower than 60 knots.

Additionally, the phrase ‘‘but no lower

than 60 knots’’ was added to

recommendation (1) of the Normal

Procedures section because of the

possibility that at higher altitudes, 0.9

Vne could be lower than 60 knots. Below

60 knots, the energy required to recover

from a low-rotor RPM condition by

flaring the helicopter and converting

forward airspeed to rotor speed is

unavailable. The reference to the

requirement to report compliance that

was contained in paragraph (b) of the

existing Priority Letter AD has been

deleted since part 91.147(a)(2)(v)

already contains that requirement.

Finally, another paragraph has been

inserted to state that special flight

permits will not be issued to operators

for the purpose of obtaining and

inserting the three pages into the

rotorcraft flight manual. Due to the

immediate compliance time and the

criticality of preventing M/R blade

contacts with the fuselage, this rule is

being issued immediately to revise the

operating limitation of the helicopter to

a safer level.

Since an unsafe condition has been

identified that is likely to exist or

develop on other Robinson Helicopter

Company Model R44 helicopters of the

same type design, this AD supersedes

Priority Letter AD 95–02–04 to require

the same revisions to the Limitations
11612 Federal Register / Vol. 60, No. 41 / Thursday, March 2, 1995 / Rules and Regulations

section, the Normal Procedures section,

and the Emergency Procedures section

of the R44 Rotorcraft Flight Manual,

revised September 6, 1994, that were

required by the Priority Letter AD, but

deletes the words ‘‘areas of forecasted or

reported’’ from the wind turbulence

limitation; adds the word ‘‘spreads’’

when referencing wind gusts; adds the

phrase ‘‘but no lower than 60 knots’’ to

the same section; deletes the reference

to the requirement to record compliance

that was contained in paragraph (b) of

the existing Priority Letter AD; and,

adds another paragraph to state that

special flight permits will not be issued

to accomplish the requirements of this

AD.

Since a situation exists that requires

the immediate adoption of this

regulation, it is found that notice and

opportunity for prior public comment

hereon are impracticable, and that good

cause exists for making this amendment

effective in less than 30 days.

Comments Invited

Although this action is in the form of

a final rule that involves requirements

affecting flight safety and, thus, was not

preceded by notice and an opportunity

for public comment, comments are

invited on this rule. Interested persons

are invited to comment on this rule by

submitting such written data, views, or

arguments as they may desire.

Communications should identify the

Rules Docket number and be submitted

in triplicate to the address specified

under the caption ADDRESSES. All

communications received on or before

the closing date for comments will be

considered, and this rule may be

amended in light of the comments

received. Factual information that

supports the commenter’s ideas and

suggestions is extremely helpful in

evaluating the effectiveness of the AD

action and determining whether

additional rulemaking action would be

needed.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the rule that might suggest a need to

modify the rule. All comments

submitted will be available, both before

and after the closing date for comments,

in the Rules Docket for examination by

interested persons. A report that

summarizes each FAA-public contact

concerned with the substance of this AD

will be filed in the Rules Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this rule must

submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket No. 95–SW–12–AD.’’ The

postcard will be date stamped and

returned to the commenter.

The regulations adopted herein will

not have substantial direct effects on the

States, on the relationship between the

national government and the States, or

on the distribution of power and

responsibilities among the various

levels of government. Therefore, in

accordance with Executive Order 12612,

it is determined that this final rule does

not have sufficient federalism

implications to warrant the preparation

of a Federalism Assessment.

The FAA has determined that this

regulation is an emergency regulation

that must be issued immediately to

correct an unsafe condition in aircraft,

and that it is not a ‘‘significant

regulatory action’’ under Executive

Order 12866. It has been determined

further that this action involves an

emergency regulation under DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979). If it is

determined that this emergency

regulation otherwise would be

significant under DOT Regulatory

Policies and Procedures, a final

regulatory evaluation will be prepared

and placed in the Rules Docket. A copy

of it, if filed, may be obtained from the

Rules Docket at the location provided

under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Safety.

Adoption of the Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration amends part 39 of the

Federal Aviation Regulations (14 CFR

part 39) as follows:

PART 39—AIRWORTHINESS

DIRECTIVES

1. The authority citation for part 39

continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421

and 1423; 49 U.S.C. 106(g); and 14 CFR

11.89.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding a new airworthiness directive

(AD), Amendment 39–9165, to read as

follows:

95–04–13 Robinson Helicopter Company:

Amendment 39–9165. Docket No. 95–

SW–12–AD. Supersedes Priority Letter

AD 95–02–04, issued January 12, 1995.

Applicability: Model R44 helicopters,

certificated in any category.

Compliance: Required before further flight,

unless accomplished previously.

To prevent main rotor (M/R) stall or mast

bumping, which could result in the M/R

blades contacting the fuselage causing failure

of the M/R system and subsequent loss of

control of the helicopter, accomplish the

following:

(a) Insert the following information into the

Model R44 Rotorcraft Flight Manual, revised

September 6, 1994. Compliance with the

Limitations section is mandatory. The

Normal Procedures and Emergency

Procedures sections are informational.

Limitations Section

(1) Flight when surface winds exceed 25

knots, including gusts, is prohibited.

(2) Flight when surface wind gust spreads

exceed 15 knots is prohibited.

(3) Flight in wind shear is prohibited.

(4) Flight in moderate, severe, or extreme

turbulence is prohibited.

(5) Adjust forward airspeed to between 60

knots and 0.7 Vne but no lower than 60 knots

upon inadvertently encountering moderate,

severe, or extreme turbulence.

Note: Moderate turbulence is turbulence

that causes: (1) Changes in altitude or

attitude; (2) variations in indicated airspeed;

and (3) aircraft occupants to feel definite

strains against seat belts.

Normal Procedures Section

Note

Until the FAA completes its research into

the conditions and aircraft characteristics

that lead to main rotor blade/fuselage contact

accidents, and corrective type design changes

and operating limitations are identified, R44

pilots are strongly urged to become familiar

with the following information and comply

with these recommended procedures.

Main Rotor Stall: Many factors may

contribute to main rotor stall and pilots

should be familiar with them. Any flight

condition that creates excessive angle of

attack on the main rotor blades can produce

a stall. Low main rotor RPM, aggressive

maneuvering, high collective angle (often the

result of high-density altitude, over-pitching

[exceeding power available] during climb, or

high forward airspeed) and slow response to

the low main rotor RPM warning horn and

light may result in main rotor stall. The effect

of these conditions can be amplified in

turbulence. Main rotor stall can ultimately

result in contact between the main rotor and

airframe. Additional information on main

rotor stall is provided in the Robinson

Helicopter Company Safety Notices SN–10,

SN–15, SN–20, SN–24, SN–27, and SN–29.

Mast Bumping: Mast bumping may occur

with a teetering rotor system when excessive

main rotor flapping results from low ‘‘G’’

(load factor below 1.0) or abrupt control

input. A low ‘‘G’’ flight condition can result

from an abrupt cyclic pushover in forward

flight. High forward airspeed, turbulence,

and excessive sideslip can accentuate the

adverse effects of these control movements.

The excessive flapping results in the main

rotor hub assembly striking the main rotor

mast with subsequent main rotor system

separation from the helicopter.

To avoid these conditions, pilots are

strongly urged to follow these

recommendations:
Federal Register / Vol. 60, No. 41 / Thursday, March 2, 1995 / Rules and Regulations 11613

(1) Maintain cruise airspeeds greater than

60 knots indicated airspeed and less than 0.9

Vne, but no lower than 60 knots.

(2) The possibility of rotor stall is increased

at high density altitudes; therefore, avoid

flight at high density altitudes.

(3) Use maximum ‘‘power-on’’ RPM at all

times during powered flight.

(4) Avoid sideslip during flight. Maintain

in-trim flight at all times.

(5) Avoid large, rapid forward cyclic inputs

in forward flight, and abrupt control inputs

in turbulence.

Emergency Procedures Section

(1) RIGHT ROLL IN LOW ‘‘G’’ CONDITION

Gradually apply aft cyclic to restore

positive ‘‘G’’ forces and main rotor thrust. Do

not apply lateral cyclic until positive ‘‘G’’

forces have been established.

(2) UNCOMMANDED PITCH, ROLL, OR

YAW RESULTING FROM FLIGHT IN

TURBULENCE.

Gradually apply controls to maintain rotor

RPM, positive ‘‘G’’ forces, and to eliminate

sideslip. Minimize cyclic control inputs in

turbulence; do not over control.

(3) INADVERTENT ENCOUNTER WITH

MODERATE, SEVERE, OR EXTREME

TURBULENCE.

If the area of turbulence is isolated, depart

the area; otherwise, land the helicopter as

soon as practical.

(b) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used when approved by the Manager,

Rotorcraft Standards Staff, FAA, Rotorcraft

Directorate. Operators shall submit their

requests through an FAA Principal

Operations Inspector, who may concur or

comment and then send it to the Manager,

Rotorcraft Standards Staff.

Note: Information concerning the existence

of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Rotorcraft Standards Staff.

(c) Special flight permits, pursuant to

sections 21.197 and 21.199 of the Federal

Aviation Regulations (14 CFR 21.197 and

21.199), will not be issued.

(d) This amendment becomes effective on

March 17, 1995.

Issued in Fort Worth, Texas, on February

23, 1995.

Eric Bries,

Acting Manager, Rotorcraft Directorate,

Aircraft Certification Service.

[FR Doc. 95–5096 Filed 3–1–95; 8:45 am]

BILLING CODE 4910–13–P

14 CFR Part 39

[Docket No. 95–SW–11–AD; Amendment

39–9166; AD 95–04–14]

Airworthiness Directives; Robinson

Helicopter Company Model R22

Helicopters

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to Robinson Helicopter

Company Model R22 helicopters, that

currently requires revisions to the

Limitations section, the Normal

Procedures section, and the Emergency

Procedures section of the R22 Rotorcraft

Flight Manual, revised February 4, 1993.

These revisions limit operations in high

winds and turbulence; provide

information about main rotor (M/R)

stalls and mast bumping; and, provide

recommendations for avoiding these

situations. Additionally, emergency

procedures are provided for use should

certain conditions be encountered. This

amendment requires the same revisions

required by the existing Priority Letter

AD, but revises certain words and

phrases to further clarify the revised

Limitations and Normal Procedures

sections, deletes the paragraph that

referenced recording compliance with

the AD, and adds another paragraph that

states that no special flight permits will

be issued prior to compliance with this

AD. This amendment is prompted by 26

accidents since 1981 that resulted in

fatalities and involved the M/R blades

contacting the helicopters’ fuselage. The

actions specified by this AD are

intended to prevent M/R stall or mast

bumping, which could result in the M/

R blades contacting the fuselage causing

failure of the M/R system and

subsequent loss of control of the

helicopter.

DATES: Effective March 17, 1995.

Comments for inclusion in the Rules

Docket must be received on or before

May 1, 1995.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Office of the

Assistant Chief Counsel, Attention:

Rules Docket No. 95–SW–11–AD, 2601

Meacham Blvd., Room 663, Fort Worth,

Texas 76137.

FOR FURTHER INFORMATION CONTACT: Mr.

Scott Horn, Aerospace Engineer, FAA,

Rotorcraft Directorate, Rotorcraft

Standards Staff, Southwest Region, 2601

Meacham Blvd., Fort Worth, Texas

76137, telephone (817) 222–5125, fax

(817) 222–5961.

SUPPLEMENTARY INFORMATION: On

January 12, 1995, the FAA issued

Priority Letter AD 95–02–03, to require

revisions to the Limitations section, the

Normal Procedures section, and the

Emergency Procedures section of the

R22 Rotorcraft Flight Manual, revised

February 4, 1993. These revisions limit

operations in high winds, turbulence,

and wind shear conditions; provide

information about M/R stalls and mast

bumping; and, provide

recommendations for avoiding these

situations. That action was prompted by

26 Model R22 accidents since 1981

involving M/R blades contacting the

helicopters’ fuselage. M/R stall and mast

bumping may have caused these M/R

blade contacts with the fuselage. All of

these accidents resulted in fatalities.

Limited pilot experience in rotorcraft

has been identified as common to these

accidents. High winds and turbulence

were also noted in some of the

accidents. Airspeed and low rotor RPM

could also be influencing factors in

these M/R blades contacting the

fuselage. Flight in strong or gusty winds,

areas of wind shear, or areas of

moderate, severe, or extreme turbulence

can degrade the helicopter handling

qualities, thereby creating an unsafe

condition. These conditions, if not

compensated for, could result in M/R

stall or mast bumping, which could

result in the M/R blades contacting the

fuselage causing failure of the M/R

system and subsequent loss of control of

the helicopter.

Since the issuance of that AD, the

FAA has determined that the words

‘‘areas of forecasted or reported’’ should

be deleted from the revision to the

Limitations section of the Model R22

Rotorcraft Flight Manual, revised

February 4, 1993. Some operators

receive area forecasts and reports that

cover wide geographic regions. These

forecasts and reports can refer to

turbulence in areas unrelated to the

actual area of operation. Forecasted or

reported wind shear or turbulence

outside of the operational area was not

intended to be a flight limitation. The

word ‘‘spreads’’ was added to the term

‘‘wind gusts’’ to define this limitation as

the spread or variance of wind

velocities. The phrase ‘‘but no lower

than 60 knots’’ was added to the

Limitations section because of the

possibility that at higher altitudes, 0.7

Vne could be lower than 60 knots.

Additionally, the phrase ‘‘but no lower

than 60 knots’’ was added to

recommendation (1) of the Normal

Procedures section because of the

possibility that at higher altitudes, 0.9

Vne could be lower than 60 knots. Below

60 knots, the energy required to recover

from a low-rotor RPM condition by

flaring the helicopter and converting

forward airspeed to rotor speed is

unavailable. The reference to the

requirement to record compliance that

was contained in paragraph (b) of the

existing Priority Letter AD has been

deleted since part 91.417(a)(2)(v)