Airworthiness Directives; British Aerospace Model BAe 146-100A, - 200A, and -300A, and Model Avro 146-RJ70A, -RJ85A, and -RJ100A Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-NM-152-AD]

Airworthiness Directives; British Aerospace Model BAe 146-100A, -

200A, and -300A, and Model Avro 146-RJ70A, -RJ85A, and -RJ100A Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing

airworthiness directive (AD), applicable to certain British Aerospace

Model BAe 146-00A, -200A, and -300A series airplanes, that currently

requires repetitive inspections of the attachment bolts and nuts in the

left- and right-hand rear spar root joint attachment fittings at wing

rib 2 for integrity of nuts, tightness of bolts, and/or fuel leaks; and

repair, if necessary. That AD was prompted by reports of fuel leaks

from bolt positions on the rear spar attachment fitting at wing rib 2.

This action would provide an optional terminating modification for the

repetitive inspections and would expand the applicability of the

existing AD to include additional airplanes. The actions specified by

the proposed AD are intended to prevent fuel leaks and a subsequent

fire.

DATES: Comments must be received by January 10, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 94-NM-152-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-152-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-152-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

On April 4, 1990, the FAA issued AD 90-08-15, amendment 39-6577 (55

FR 13757, April 12, 1990), applicable to certain British Aerospace

Model BAe 146-00A, -200A, and -300A series airplanes, to require

repetitive inspections of the attachment bolts and nuts in the left-

and right-hand rear spar root joint attachment fittings at wing rib 2

for integrity of nuts, tightness of bolts, and/or fuel leaks; and

repair, if necessary. That action was prompted by reports of fuel leaks

from bolt positions on the rear spar attachment fitting at wing rib 2.

The requirements of that AD are intended to prevent fuel leaks, and

subsequently, the initiation of a fire.

Since the issuance of that AD, Avro International Aerospace (a

division of British Aerospace) has issued Revision 1, dated October 29,

1993; Revision 2, dated February 16, 1994; and Revision 3, dated

September 16, 1994; of Service Bulletin S.B. 57-33. The inspection

procedures described in these revisions are identical to those

described in the original issue of the service bulletin (which was

referenced in AD 90-08-15).

Revision 1 of the service bulletin expands the effectivity listing

to include Model Avro 146-RJ series airplanes that are subject to the

addressed unsafe condition. Revision 2 of the service bulletin changes

the effectivity listing to include the specific airplane constructor

numbers of certain other airplanes. Revision 3 of the service bulletin

extends the interval for the repetitive inspections of the attachment

bolts and nuts of the rear spar root joint attachment fitting at wing

rib 2 from 3,000 to 4,000 landings.

These revisions also describe procedures for a modification that

eliminates the need for the repetitive inspections; this modification

involves the installation of tension bolts at the rear spar root joint

attachment fittings at wing rib 2. Implementation of this modification

will prevent bolt failures and eliminate the unsafe condition

identified as loss of fuel and a subsequent fire. The Civil Aviation

Authority (CAA), which is the airworthiness authority for the United

Kingdom, classified these service bulletins as mandatory.

[Note: Avro International Aerospace Service Bulletin S.B. 57-33,

Revision 1, dated October 29, 1993; Revision 2, dated February 16,

1994; and Revision 3, dated September 16, 1994; refer to Repair

Instruction Leaflets HC536H9043 and HC536H9156 for installation of

tension bolts.]

This airplane model is manufactured in the United Kingdom and is

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.

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 supersede AD 90-08-15 to

continue to require repetitive visual inspections for integrity of

nuts, tightness of bolts, and/or fuel leaks of the outboard vertical

row of fasteners at the left- and right-hand of the rear spar root

joint attachment fittings. The proposed AD would also provide for an

optional terminating modification for the repetitive inspections.

Additionally, the proposed AD would expand the applicability of the

existing AD to include Model Avro 146-RJ series airplanes and would

change the applicability to specify specific airplane constructor

numbers of certain other airplanes The actions would be required to be

accomplished in accordance with the service bulletin described

previously.

[Note: As a result of recent communications with the Air

Transport Association (ATA) of America, the FAA has learned that

some operators may misunderstand the legal effect of AD's on

airplanes that are identified in the applicability provision of the

AD, but that have been altered or repaired in the area addressed by

the AD. Under these circumstances, at least one operator appears to

have incorrectly assumed that its airplane was not subject to the

AD. On the contrary, all airplanes identified in the applicability

provision of an AD are legally subject to the AD. If an airplane has

been altered or repaired in the affected area in such a way as to

affect compliance with the AD, the owner or operator is required to

obtain FAA approval for an alternative method of compliance with the

AD, in accordance with the paragraph of each AD that provides for

such approvals. A note has been added to this notice to clarify this

requirement.]

The FAA estimates that 11 airplanes of U.S. registry would be

affected by this proposed AD, that it would take approximately 2 work

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

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

total cost impact of the proposed AD on U.S. operators is estimated to

be $1,320, or $120 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 removing amendment 39-6577 (55 FR

13757, April 12, 1990), and by adding a new airworthiness directive

(AD), to read as follows:

British Aerospace Regional Aircraft Limited, Avro International

Aerospace Division (Formerly British Aerospace, plc; British

Aerospace Commercial Aircraft Limited): Docket 94-NM-152-AD.

Supersedes AD 90-08-5, Amendment 39-0577.

Applicability: All Model British Aerospace Model BAe 146-100A, -

200A, and -300A, and Model Avro 146-RJ70A, -RJ85A, and -RJ100A

series airplanes; as listed in British Aerospace Service Bulletin SB

57-33, dated August 31, 1989, and Avro International Aerospace

Service Bulletin S.B. 57-33, Revision 3, dated September 16, 1994;

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 use the authority

provided in paragraph (d) to request approval from the FAA. This

approval may address either no action, if the current configuration

eliminates the unsafe condition; or different actions necessary to

address the unsafe condition described in this AD. Such a request

should include an assessment of the effect of the changed

configuration on the unsafe condition addressed by this AD. In no

case does the presence of any modification, alteration, or repair

remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished

previously.

To prevent fuel leaks and a subsequent fire, accomplish the

following:

(a) For airplanes listed in British Aerospace Service Bulletin

SB 57-33, dated August 31, 1989: Within 12 months after May 21, 1990

(the effective date of AD 90-08-15, amendment 39-6577), visually

inspect for integrity of nuts and tightness of bolts, and/or fuel

leaks of the outboard vertical row of fasteners at the left- and

right-hand of the rear spar root joint attachment fittings, in

accordance with British Aerospace Service Bulletin 57-33, dated

August 31, 1989, Revision 1, dated October 29, 1993; Revision 2,

dated February 16, 1994; or Revision 3, dated September 16, 1994.

Repeat the inspection thereafter at intervals not to exceed 4,000

landings.

(1) If no defects are found, prior to further flight, reinstall

the left- and right-hand wing-to-fuselage fairing panels in

accordance with the service bulletin.

(2) If any defects are found, prior to further flight, repair

suspect and leaking fasteners, in accordance with the service

bulletin.

(b) For airplanes listed in Avro International Aerospace Service

Bulletin S.B. 57-33, Revision 3, dated September 16, 1994, and not

subject to paragraph (a) of this AD: Within 12 months after the

effective date of this AD, visually inspect for integrity of nuts

and tightness of bolts, and/or fuel leaks of the outboard vertical

row of fasteners at the left- and right-hand of the rear spar root

joint attachment fittings, in accordance with Avro International

Aerospace Service Bulletin S.B. 57-33, Revision 1, dated October 29,

1993; Revision 2, dated February 16, 1994; or Revision 3, dated

September 16, 1994. Repeat the inspection thereafter at intervals

not to exceed 4,000 landings.

(1) If no defects are found, prior to further flight, reinstall

the left- and right-hand wing-to-fuselage fairing panels in

accordance with the service bulletin.

(2) If any defects are found, prior to further flight, repair

suspect and leaking fasteners in accordance with the service

bulletin.

(c) Modification of the rear spar root joint attachment fittings

at wing rib 2 in accordance with Avro International Aerospace

Service Bulletin S.B. 57-33, Revision 1, dated October 29, 1993;

Revision 2, dated February 16, 1994; or Revision 3, dated September

16, 1994; constitutes terminating action for the repetitive visual

inspections required by this AD.

(d) 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 2: Information concerning the existence of approved

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

obtained from the Standardization Branch, ANM-113.

(e) 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 22, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-29316 Filed 11-28-94; 8:45 am]

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