[Federal Register Volume 63, Number 106 (Wednesday, June 3, 1998)]
[Proposed Rules]
[Pages 30152-30154]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-14608]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-128-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Model BAe 146 and 
Model 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 certain Model Avro 146-RJ series airplanes. This proposal would 
require a one-time inspection for ``drill marks'' and corrosion on the 
underside of the wing top skin, and corrective actions, if necessary. 
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 prevent 
corrosion from developing on the underside of the top skin of the 
center wing, which could result in reduced structural integrity of the 
airplane.

DATES: Comments must be received by July 6, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-128-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 AI(R) American Support, Inc., 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:

[[Page 30153]]

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 97-NM-128-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. 97-NM-128-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, notified the FAA that an unsafe 
condition may exist on all British Aerospace BAe 146 and certain Model 
Avro 146-RJ series airplanes. The CAA advises that, the manufacturer 
randomly selected 10 production airplanes for inspection; all of these 
airplanes were found to have ``drill marks'' on the underside of the 
wing top skin inside the closed section stringers, at Rib 0 and Rib 2. 
The CAA further advises that the ``drill marks'' were made during the 
assembly of the stringer crown dagger fittings, and can impair the 
protective treatment of the skin, which protects the underside of the 
wing from exfoliation corrosion. This condition, if not corrected, 
could result in corrosion developing on the underside of the top skin 
of the center wing, and consequent reduced structural integrity of the 
airplane.

Explanation of Relevant Service Information

    The manufacturer has issued British Aerospace Service Bulletin SB. 
57-50, Revision 2, dated March 20, 1997, which describes procedures for 
repetitive intrascope inspections of the underside of the wing top skin 
inside the closed section stringers at Rib 0 and Rib 2 to detect the 
presence of ``drill marks'' and corrosion, and corrective actions, if 
necessary. Corrective actions include degreasing and applying 
protective treatment coating, which will restore the corrosion 
protection. The service bulletin indicates that application of the 
protective treatment coating would eliminate the need for repetitive 
inspections. 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 004-12-96 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, 
except as discussed below.

Differences Between the Proposed Rule and Service Bulletin

    Operators should note that, although the service bulletin described 
previously provides for repetitive inspections, this proposed AD would 
require the application of protective treatment coating, following a 
one-time inspection for ``drill marks'' and corrosion. Accomplishment 
of this application eliminates the need for the repetitive inspection. 
The FAA has determined that long-term inspections may not be providing 
the degree of safety assurance necessary for the transport airplane 
fleet. This, along with the understanding of the human factors 
associated with numerous continual inspections, has led the FAA to 
consider placing less emphasis on inspections and more emphasis on the 
corrective actions. This proposed requirement is in consonance with 
these conditions.
    Additionally, operators should note that, although the service 
bulletin specifies that the manufacturer be contacted for disposition 
of repair if any corrosion is detected, this proposal would require 
repair of any corrosion to be accomplished in accordance with a method 
approved by the FAA before applying protective treatment coating.

Cost Impact

    The FAA estimates that 40 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 10 work 
hours 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 inspection proposed by this AD on U.S. operators is 
estimated to be $24,000, or $600 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

[[Page 30154]]

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 97-NM-128-AD.

    Applicability: All Model BAe 146 series airplanes; and Model 
Avro 146-RJ series airplanes, as listed in British Aerospace Service 
Bulletin SB.57-50, Revision 2, dated March 20, 1997; 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 prevent corrosion from developing on the underside of the top 
skin of the center wing, which could result in reduced structural 
integrity of the airplane, accomplish the following:
    (a) Within 2 years after the effective date of this AD, perform 
a one-time intrascopic inspection for ``drill marks'' and corrosion 
on the underside of the wing top skin, in accordance with British 
Aerospace Service Bulletin SB.57-50, Revision 2, dated March 20, 
1997.
    (1) If no ``drill mark'' or corrosion is detected, no further 
action is required by this AD.
    (2) If any ``drill mark'' is detected, prior to further flight, 
apply protective treatment coating, in accordance with the service 
bulletin.
    (3) If any corrosion is detected, prior to further flight, 
repair in accordance with a method approved by the Manager, 
International Branch, ANM-116, FAA, Transport Directorate; and apply 
protective treatment coating 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, International Branch, ANM-116. 
Operators 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.
    (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 3: The subject of this AD is addressed in British 
airworthiness directive 004-12-96.

    Issued in Renton, Washington, on May 27, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-14608 Filed 6-2-98; 8:45 am]
BILLING CODE 4910-13-U