[Federal Register Volume 62, Number 116 (Tuesday, June 17, 1997)]
[Proposed Rules]
[Pages 32701-32703]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-15767]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-02-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 certain British Aerospace Model 
BAe 146 and Model Avro 146-RJ series airplanes. This proposal would 
require repetitive detailed visual inspections of the top wing skins 
for stress corrosion cracks, damage, or missing surface protective 
finish of the metallic surfaces; and repair, if necessary. This 
proposal is prompted by reports of stress corrosion cracks found on the 
top wing skin during routine inspection on three airplanes. The actions 
specified by the proposed AD are intended to detect and correct such 
cracking, which could result in reduced structural integrity of the 
wing.

DATES: Comments must be received by July 28, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-02-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 Limited, Avro 
International Aerospace Division, Customer Support, Woodford Aerodrome, 
Woodford, Cheshire SK7 1QR, England. This information may be examined 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Tim Backman, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2797; 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 97-NM-02-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. 97-NM-02-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 certain British Aerospace Model BAe 146 and 
Model Avro 146-RJ series airplanes. The CAA advises that airplanes with 
wing skins made from 7150-T651 aluminum are subject to stress corrosion 
cracking. During routine inspections, stress corrosion cracks on the 
top wing skin were found on three of the affected airplanes. Analysis 
has revealed that this stress corrosion cracking is only a problem on 
Model BAe 146 and Model Avro 146-RJ series airplanes with wing skins 
made from 7150-T651 aluminum. This condition, if not detected and 
corrected in a timely manner, could result in reduced structural 
integrity of the wing.

Explanation of Relevant Service Information

    British Aerospace has issued Service Bulletin SB.57-49, dated June 
4, 1996, which describes procedures for visually inspecting the top 
wing skin for stress corrosion cracks, damage, or missing surface 
protective finish of the metallic surfaces. The service bulletin also 
provides procedures for application of a protective finish of the 
metallic surfaces, if necessary. The CAA classified this service 
bulletin as mandatory and issued British airworthiness directive 005-
06-96, dated June 4, 1996, 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

[[Page 32702]]

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 repetitive detailed 
visual inspections of the top wing skins for stress corrosion cracking, 
damage, or missing surface protective finish of the metallic surfaces, 
and repair, if necessary. The proposed inspections and a certain repair 
would be required to be accomplished in accordance with the service 
bulletin described previously. Repair of any corrosion cracking would 
be required to be accomplished in accordance with a method approved by 
the FAA.

Cost Impact

    The FAA estimates that 12 British Aerospace Model BAe 146 and Model 
Avro 146-RJ series airplanes of U.S. registry would be affected by this 
proposed AD, that it would take approximately 4 work hours per airplane 
to accomplish the proposed inspections, and that the average labor rate 
is $60 per work hour. Based on these figures, the cost impact of the 
initial inspection proposed by this AD on U.S. operators is estimated 
to be $2,880, or $240 per airplane, per inspection cycle.
    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 Limited, Avro International 
Aerospace Division (Formerly British Aerospace, plc; British 
Aerospace Commercial Aircraft Limited): Docket 97-NM-02-AD.

    Applicability: Model BAe 146 and Model Avro 146-RJ series 
airplanes, certificated in any category, having wing skins made from 
7150-T651 aluminum, and having the following serial numbers:

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              Model                                                Serial numbers                               
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BAe 146-100 and 100A.............  All beginning with E1144.                                                    
BAe 146-200 and 200A.............  All beginning with E2148 (including E2227).                                  
BAe 146-300 and 300A.............  All beginning with E3141 (including E3222).                                  
Avro 146-RJ70 and 70A............  All beginning with E1223.                                                    
Avro 146-RJ85 and 85A............  E2208, and all beginning with E2226, excluding E2227.                        
Avro 146-RJ100 and 100A..........  All beginning with E3221, excluding E3222.                                   
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    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 stress corrosion cracking in the wing 
skin, which could result in reduced structural integrity of the 
wing, accomplish the following:
    (a) Within 4 months after the effective date of this AD; and 
thereafter at intervals not to exceed 4,000 landings or 2 years, 
whichever occurs first: Perform a detailed visual inspection of the 
top wing skins to detect stress corrosion cracking, and any damaged 
or missing surface protective finish that exposes the metallic 
surfaces, in accordance with British Aerospace Service Bulletin 
SB.57-49, dated June 4, 1996.
    (1) If any damaged or missing surface protective finish is 
detected, and no cracking or corrosion is detected, prior to further 
flight, reapply the protective finish in accordance with the service 
bulletin. Repeat the detailed visual inspection, thereafter, at 
intervals not to exceed 4,000 landings or 2 years, whichever occurs 
first.
    (2) If any cracking is detected, prior to further flight, repair 
in accordance with a method approved by the Manager, Standardization 
Branch, ANM-113, FAA, Transport Airplane Directorate.

    Note 2: During the detailed visual inspections of the top wing 
skins, pay particular attention to the edge of cutouts, skin edges, 
and attachment bolt holes.

    (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. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then

[[Page 32703]]

send it to the Manager, Standardization Branch, ANM-113.

    Note 3: 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 June 10, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-15767 Filed 6-16-97; 8:45 am]
BILLING CODE 4910-13-U