Airworthiness Directives; British Aerospace Model Avro 146-RJ70A and -RJ85A Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-NM-132-AD]

Airworthiness Directives; British Aerospace Model Avro 146-RJ70A

and -RJ85A Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to certain British Aerospace Model

Avro 146-RJ70A and -RJ85A series airplanes. This proposal would require

an inspection to identify and remove certain cable terminals on the

auxiliary power unit (APU) starter circuit and installation of certain

new cable terminals. This proposal is prompted by a report that, during

an inspection of the cable terminals on the APU starter circuit,

incorrect cable terminals were found installed on these airplanes. The

actions specified by the proposed AD are intended to ensure the

installation of correct starter cable terminals in the APU; incorrect

cables could lead to the inability of the pilot to start the APU when

needed in a situation of loss of other electrical power sources.

DATES: Comments must be received by January 4, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 94-NM-132-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056. Comments may be inspected at this

location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except

Federal holidays.

The service information referenced in the proposed rule may be

obtained from British Aerospace Holdings, Inc., Avro International

Aerospace Division, P.O. Box 16039, Dulles International Airport,

Washington DC 20041-6039. This information may be examined at the FAA,

Transport Airplane Directorate, 1601 Lind Avenue SW, Renton,

Washington.

FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer,

Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)

227-2148; fax (206) 227-1320.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the

proposed rule by submitting such written data, views, or arguments as

they may desire. Communications shall identify the Rules Docket number

and be submitted in triplicate to the address specified above. All

communications received on or before the closing date for comments,

specified above, will be considered before taking action on the

proposed rule. The proposals contained in this notice may be changed in

light of the comments received.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with

the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this notice must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket Number 94-NM-132-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request

to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules

Docket No. 94-NM-132-AD, 1601 Lind Avenue SW., Renton, Washington

98055-4056.

Discussion

The Civil Aviation Authority (CAA), which is the airworthiness

authority for the United Kingdom, recently notified the FAA that an

unsafe condition may exist on certain British Aerospace Model Avro 146-

RJ70A and -RJ85A series airplanes. The CAA advises that, during an

inspection of the cable terminals in the auxiliary power unit (APU)

starter circuit, incorrect cable terminals were found installed on

these airplanes. Investigation revealed that nickel-plated copper

terminals were installed during production instead of aluminum/copper

terminals. Nickel-plated copper terminals that contact APU starter

cables having an aluminum core result in dissimilar metal corrosion.

Such corrosion could lead to the loss of power to the APU, and the

consequent inability of the pilot to start the APU when necessary in a

situation where an airplane's primary or other electrical power sources

are lost. If this were to occur, all electrical power on the airplane

may be lost.

Avro has issued Service Bulletin S.B. 49-40, Revision 1, dated

March 17, 1994, which describes procedures for a detailed visual

inspection to identify the cable terminals fitted to cables KA47 and

KA48 in the APU starter circuit at terminal block KA9. This service

bulletin also describes procedures for removing the cable terminals

identified as part number (P/N) S1007-042 and installing new cable

terminals having P/N S1006-040. The CAA classified this service

bulletin as mandatory.

This airplane model is manufactured in the United Kingdom and is

type certificated for operation in the United States under the

provisions of Sec. 21.29 of the Federal Aviation Regulations (14 CFR

21.29) and the applicable bilateral airworthiness agreement. Pursuant

to this bilateral airworthiness agreement, the CAA has kept the FAA

informed of the situation described above. The FAA has examined the

findings of the CAA, reviewed all available information, and determined

that AD action is necessary for products of this type design that are

certificated for operation in the United States.

Since an unsafe condition has been identified that is likely to

exist or develop on other airplanes of the same type design registered

in the United States, the proposed AD would require a detailed visual

inspection to identify the cable terminals fitted to cables KA47 and

KA48 on the APU starter circuit at terminal block KA9, removal of

certain cable terminals, and installation of certain new cable

terminals. The actions would be required to be accomplished in

accordance with the service bulletin described previously.

The FAA estimates that 3 airplanes of U.S. registry would be

affected by this proposed AD, that it would take approximately 1.5 work

hours per airplane to accomplish the proposed actions, and that the

average labor rate is $55 per work hour. Required parts would cost

approximately $250 per airplane. Based on these figures, the total cost

impact of the proposed AD on U.S. operators is estimated to be $997.50,

or $332.50 per airplane.

The total cost impact figure discussed above is based on

assumptions that no operator has yet accomplished any of the proposed

requirements of this AD action, and that no operator would accomplish

those actions in the future if this AD were not adopted.

The regulations proposed herein would 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

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this proposed

regulation (1) is not a ``significant regulatory action'' under

Executive Order 12866; (2) is not a ``significant rule'' under the DOT

Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);

and (3) if promulgated, will not have a significant economic impact,

positive or negative, on a substantial number of small entities under

the criteria of the Regulatory Flexibility Act. A copy of the draft

regulatory evaluation prepared for this action is contained in the

Rules Docket. A copy of it may be obtained by contacting 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.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration proposes to amend

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 adding the following new

airworthiness directive:

British Aerospace Regional Aircraft Limited, Avro International

Aerospace Division (Formerly British Aerospace, PLC; British

Aerospace Commercial Aircraft Limited): Docket 94-NM-132-AD.

Applicability: Model Avro 146-RJ70A and -RJ85A series airplanes;

as listed in Avro International Aerospace Service Bulletin 49-40,

Revision 1, dated March 17, 1994; certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent loss of electrical power to the auxiliary power unit

(APU), accomplish the following:

(a) Within 5 months after the effective date of this AD, perform

a detailed visual inspection to identify the cable terminals fitted

to cables KA47 and KA48 in the APU starter circuit at terminal block

KA9, in accordance with Avro International Aerospace Service

Bulletin S.B. 49-40, Revision 1, dated March 17, 1994. If the cable

terminals are identified as part number (P/N) S1007-042, prior to

further flight, remove the cable terminals and install new cable

terminals having P/N S1006-040, in accordance with the service

bulletin.

(b) An alternative method of compliance or adjustment of the

compliance time that provides an acceptable level of safety may be

used if approved by the Manager, Standardization Branch, ANM-113,

FAA, Transport Airplane Directorate. Operators shall submit their

requests through an appropriate FAA Principal Maintenance Inspector,

who may add comments and then send it to the Manager,

Standardization Branch, ANM-113.

Note: Information concerning the existence of approved

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

obtained from the Standardization Branch, ANM-113.

(c) Special flight permits may be issued in accordance with

sections 21.197 and 21.199 of the Federal Aviation Regulations (14

CFR 21.197 and 21.199) to operate the airplane to a location where

the requirements of this AD can be accomplished.

Issued in Renton, Washington, on November 1, 1994.

S.R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-27475 Filed 11-4-94; 8:45 am]

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