Airworthiness Directives; British Aerospace Model BAe 146 and Avro 146-RJ Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-347-AD]

RIN 2120-AA64

Airworthiness Directives; British Aerospace Model BAe 146 and

Avro 146-RJ 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 all British Aerospace Model BAe

146 and Avro 146-RJ series airplanes. This proposal would require a

one-time inspection to detect cracking or corrosion of the forward

attachment bolts of the engine pylon to wing interface, and corrective

action, if necessary. It would also require re-installation with re-

protected and sealed bolts torqued to a lower level. This proposal is

prompted by issuance of mandatory continuing airworthiness information

by a foreign civil airworthiness authority. The actions specified by

the proposed AD are intended to detect and correct corrosion or

cracking of the forward attachment bolts of the engine pylon to wing

interface, which could result in reduced structural integrity of the

engine pylon attachment.

DATES: Comments must be received by January 14, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 99-NM-347-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 Regional Aircraft American Support,

13850 Mclearen Road, Herndon, Virginia 20171. This information may be

examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,

SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager,

International Branch, ANM-116, FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)

227-2110; fax (425) 227-1149.

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 99-NM-347-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-114, Attention: Rules

Docket No. 99-NM-347-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 all British Aerospace Model BAe 146 and

Avro 146-RJ series airplanes. The CAA advises that in-service airplanes

have suffered a total of eight failures of engine pylon to wing forward

attachment bolts, due to corrosion in the bolt head undercut. This

condition, if not corrected, could result in reduced structural

integrity of the engine pylon attachment.

Explanation of Relevant Service Information

British Aerospace has issued Service Bulletin SB.54-10, dated

September 16,

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1999, which describes procedures for a one-time dye penetrant or

magnetic particle inspection to detect cracking, and a one-time

detailed visual inspection to detect corrosion, of the forward

attachment bolts of the engine pylon to wing interface. If any cracking

is found, the bolts are to be replaced with new parts. If any corrosion

is found, the bolts are to be cleaned or replaced with new parts,

depending on the location and severity of the corrosion. The service

bulletin also details re-installation with re-protected and sealed

bolts torqued to a lower level. Accomplishment of the actions specified

in the service bulletin is intended to adequately address the

identified unsafe condition. The CAA classified this service bulletin

as mandatory and issued British airworthiness directive 006-09-99 in

order to assure the continued airworthiness of these airplanes in the

United Kingdom.

FAA's Conclusions

These airplane models are manufactured in the United Kingdom and

are type certificated for operation in the United States under the

provisions of section 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.

Explanation of Requirements of Proposed Rule

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 accomplishment of

the actions specified in the service bulletin described previously.

Cost Impact

The FAA estimates that 35 airplanes of U.S. registry would be

affected by this proposed AD, that it would take approximately 20 work

hours (including removal and reinstallation of the engines) per

airplane to accomplish the proposed inspection, and that the average

labor rate is $60 per work hour. Based on these figures, the cost

impact of the proposed AD on U.S. operators is estimated to be $42,000,

or $1,200 per airplane.

The 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.

Regulatory Impact

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. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

British Aerospace Regional Aircraft (Formerly British Aerospace

Regional Aircraft Limited, Avro International Aerospace Division;

British Aerospace, PLC; British Aerospace Commercial Aircraft

Limited): Docket 99-NM-347-AD.

Applicability: All Model BAe 146 and Avro 146-RJ series

airplanes, certificated in any category.

Note 1: This AD applies to each airplane identified in the

preceding applicability provision, regardless of whether it has been

modified, altered, or repaired in the area subject to the

requirements of this AD. For airplanes that have been modified,

altered, or repaired so that the performance of the requirements of

this AD is affected, the owner/operator must request approval for an

alternative method of compliance in accordance with paragraph (b) of

this AD. The request should include an assessment of the effect of

the modification, alteration, or repair on the unsafe condition

addressed by this AD; and, if the unsafe condition has not been

eliminated, the request should include specific proposed actions to

address it.

Compliance: Required as indicated, unless accomplished

previously.

To detect and correct cracking or corrosion of the forward

attachment bolts of the engine pylon to wing interface, which could

result in reduced structural integrity of the engine pylon

attachment, accomplish the following:

Inspection and Corrective Action

(a) Within 4 years since date of manufacture, or within 2,000

flight cycles after the effective date of this AD, whichever occurs

later: Perform applicable inspections (dye penetrant, magnetic

particle, and detailed visual) to detect discrepancies (including

damage, cracking, and corrosion) of the forward attachment bolts of

the engine pylon to wing interface on each engine, in accordance

with British Aerospace Service Bulletin SB.54-10, dated September

16, 1999. If any discrepancy is detected, prior to further flight,

perform applicable corrective actions in accordance with the service

bulletin.

Note 2: For the purposes of this AD, a detailed visual

inspection is defined as: ``An intensive visual examination of a

specific structural area, system, installation, or assembly to

detect damage, failure, or irregularity. Available lighting is

normally supplemented with a direct source of good lighting at

intensity deemed appropriate by the inspector. Inspection aids such

as mirror, magnifying lenses, etc., may be used. Surface cleaning

and elaborate access procedures may be required.''

Alternative Methods of Compliance

(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, International Branch, ANM-116, FAA,

Transport Airplane Directorate. Operators

[[Page 69969]]

shall submit their requests through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, International Branch, ANM-116.

Note 3: Information concerning the existence of approved

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

obtained from the International Branch, ANM-116.

Special Flight Permits

(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.

Note 4: The subject of this AD is addressed in British

airworthiness directive 006-09-99.

Issued in Renton, Washington, on December 9, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-32511 Filed 12-14-99; 8:45 am]

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