Airworthiness Directives; Robinson Helicopter Company Model R44 Series Helicopters

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-SW-18-AD; Amendment 39-9105; AD 94-26-10]

Airworthiness Directives; Robinson Helicopter Company Model R44

Series Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing airworthiness directive

(AD), applicable to Robinson Helicopter Company (RHC) Model R44 series

helicopters, that currently requires removal and replacement of

specific parts of the cyclic control system. This amendment requires

the same removal and replacement of specific parts of the cyclic

control system, corrects a replacement part number, and changes the

applicability to cover certain serial-numbered helicopters. This

amendment is prompted by the need to correct the existing AD by

changing the applicability to include additional serial-numbered

helicopters and to correct a replacement part number that was

incorrectly stated in the existing AD. The actions specified by this AD

are intended to prevent failure of the cyclic control system and

subsequent loss of control of the helicopter.

DATES: Effective January 11, 1995.

Comments for inclusion in the Rules Docket must be received on or

before February 27, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Office of the Assistant Chief Counsel, Attention:

Rules Docket No. 94-SW-18-AD, 2601 Meacham Blvd., Room 663, Fort Worth,

Texas 76137.

FOR FURTHER INFORMATION CONTACT: Ms. Lirio Liu, Aerospace Engineer, Los

Angeles Aircraft Certification Office, FAA, ANM-123L, Transport

Airplane Directorate, 3960 Paramount Blvd., Lakewood, California 90712,

telephone (310) 627-5229, fax (310) 627-5210.

SUPPLEMENTARY INFORMATION: On August 18, 1994, the FAA issued AD 94-17-

18, Amendment 39-9013 (59 FR 43726, August 25, 1994), to require

immediate removal and replacement of specific parts of the cyclic

control system in accordance with the applicable maintenance manual.

That action was prompted by an accident involving an RHC Model R44

series helicopter. The National Transportation Safety Board (NTSB)

determined the probable cause for the accident was fatigue failure of

the cyclic stick assembly, a part of the cyclic control system. The

pilot uses the cyclic control system to control the flight attitude of

the helicopter. If the cyclic control system fails, the pilot loses the

ability to make cyclic control inputs to the main rotor system. After

reviewing the NTSB report, the FAA has determined that certain parts of

the same design as those installed on the accident helicopter need to

be replaced before further flight. That condition, if not corrected,

could result in failure of the cyclic control system and subsequent

loss of control of the helicopter.

Since the issuance of that AD, the FAA has become aware of an error

in the AD. One of the cyclic control system replacement part numbers

was incorrectly stated as C211-3. That part number should have been

part number A211-3. Additionally, that AD should have been applicable

to RHC Model R44 series helicopters, with serial numbers (S/N) less

than but not including S/N 0017, since the manufacturing records

indicate the design changes required by that AD were incorporated by

RHC into the RHC Model R44 production line, beginning with helicopter

S/N 0017. Upon review, the FAA has determined that the original cyclic

control system design meets existing FAA design standards, but has

limited damage tolerance characteristics and does not display slow

crack growth properties. When damaged or flawed, the cyclic stick

assembly can fail due to fatigue prior to its retirement time of 4,000

hours time-in-service.

Since an unsafe condition has been identified that is likely to

exist or develop on other RHC Model R44 series helicopters of the same

type design, this AD supersedes AD 94-17-18 and is being issued to

prevent failure of the cyclic control system and subsequent loss of

control of the helicopter. This AD requires removal and replacement of

certain parts of the cyclic control system of the affected helicopters

as well as changes the applicability of this AD to include certain

serial-numbered helicopters. The actions are required to be

accomplished in accordance with the applicable maintenance manual. Due

to the critical need to (1) ensure the integrity of the cyclic control

system, (2) comply with the requirements of this AD before further

flight, and (3) require replacement of certain parts on certain serial-

numbered helicopters, this rule must be issued immediately to correct

an unsafe condition in the affected helicopters.

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. 94-SW-18-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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing Amendment 39-9013 (59 FR

43726, August 25, 1994), and by adding a new airworthiness directive

(AD), Amendment 39-9105, to read as follows:

94-26-10 Robinson Helicopter Company: Amendment 39-9105. Docket No.

94-SW-18-AD. Supersedes AD 94-17-18, Amendment 39-9013.

Applicability: Model R44 series helicopters with serial numbers

(S/N) less than but not including S/N 0017, certificated in any

category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent failure of the cyclic control system and subsequent

loss of control of the helicopter, accomplish the following:

(a) Before further flight, remove the following cyclic control

system parts and replace them with the corresponding replacement

parts in accordance with the applicable maintenance manual:

Remove part numbers: Replace with part numbers:

A205-3........................... A205-5 Revision J or subsequent FAA-

approved revisions.

C175-1........................... C175-2 Revision H or subsequent FAA-

approved revisions.

C176-1........................... C176-2 Revision B or subsequent FAA-

approved revisions.

C177-1........................... C177-2 Revision F or subsequent FAA-

approved revisions.

C319-1........................... C319-3 Revision I or subsequent FAA-

approved revisions.

C320-1........................... C320-1 Revision L or subsequent FAA-

approved revisions.

C958-4........................... C958-5 Revision E or subsequent FAA-

approved revisions.

A101-4........................... D173-1 Revision A or subsequent FAA-

approved revisions.

C338-1........................... C338-4 Revision C or subsequent FAA-

approved revisions.

A211-2........................... A211-3 Revision I or subsequent FAA-

approved revisions.

A137-1........................... A137-2 Revision C or subsequent FAA-

approved revisions.

(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, Los Angeles Aircraft

Certification Office. Operators shall submit their requests through

an FAA Principal Maintenance Inspector, who may concur or comment

and then send it to the Manager, Los Angeles Aircraft Certification

Office.

Note: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Los Angeles Aircraft Certification Office.

(c) Special flight permits will not be issued.

(d) This amendment becomes effective on January 11, 1995.

Issued in Fort Worth, Texas, on December 16, 1994.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 94-31597 Filed 12-23-94; 8:45 am]

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