[Federal Register Volume 65, Number 125 (Wednesday, June 28, 2000)]
[Proposed Rules]
[Pages 39831-39833]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-16359]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-355-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 inspections and torque checks of the stringer crown fittings 
and bolts at Ribs 0 and 2 of the wings for discrepancies, corrective 
action, if necessary; and eventual modification of the stringer crown 
fittings, which would terminate the inspections and checks. This action 
is necessary to prevent increased loads on the upper wing skin due to 
looseness of the stringer fittings and bolts at Ribs 0 and 2 of the 
wings, which could result in reduced structural integrity of the wings. 
This action is intended to address the identified unsafe condition.

DATES: Comments must be received by July 28, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-355-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. Comments may also be sent via the Internet using the 
following address: [email protected]. Comments sent via the 
Internet must contain ``Docket No. 99-NM-355-AD'' in the subject line 
and need not be submitted in triplicate. Comments sent via the Internet 
as attached electronic files must be formatted in Microsoft Word 97 for 
Windows or ASCII text.
    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.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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-355-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-355-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 Model BAe 146 and certain 
Model Avro 146-RJ series airplanes. The CAA advises that, during in-
service maintenance inspections inside the upper part of the center and 
outer wing fuel tanks at Ribs 0 and 2, loose Jo-bolts and movement at 
the stringer crown fittings have been found. Movement in this area will 
cause increased loads on the upper wing skin. This condition, if not 
corrected, could result in reduced structural integrity of the wings.

Explanation of Relevant Service Information

    British Aerospace has issued Service Bulletin SB.57-56, dated 
September 2, 1999, which describes procedures for repetitive detailed 
visual inspections of the stringers and torque checks of the Jo-bolts 
at Ribs 0 and 2 of the wings for discrepancies. The discrepancies 
include loose Jo-bolts, loose stringer crown fittings, fretting of 
fittings and stringers, and cracking or other damage of attachments to 
the upper skin and joint plates. The service bulletin also describes 
procedures for modification of all stringer crown fittings at Ribs 0 
and 2 of the wings, which would eliminate the need for the repetitive 
inspections. The modification includes detailed visual and eddy current 
inspections for discrepancies (i.e., fretting, cracking, corrosion) of 
the stringers, fittings, and upper wing skin; repairs, if necessary; 
and installation of oversize interference fit radial-lock fasteners per 
Repair Instruction (R.I.L. HC571H9033).
    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 004-09-99 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

[[Page 39832]]

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.

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 Proposed Rule and the Service Bulletin

    Operators should note that, although the service bulletin specifies 
that the manufacturer may be contacted for disposition of certain 
repair conditions, this proposal would require the repair of those 
conditions to be accomplished in accordance with a method approved by 
either the FAA or the CAA (or its delegated agent). In light of the 
type of repair that would be required to address the identified unsafe 
condition, and in consonance with existing bilateral airworthiness 
agreements, the FAA has determined that, for this proposed AD, a repair 
approved by either the FAA or the CAA would be acceptable for 
compliance with this proposed AD.

Cost Impact

    The FAA estimates that 20 airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 8 work hours per airplane to accomplish 
the proposed inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the proposed inspection on 
U.S. operators is estimated to be $9,600, or $480 per airplane, per 
inspection cycle.
    It would take approximately 450 work hours per airplane (including 
access and close) to accomplish the proposed modification, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the proposed modification on U.S. operators is estimated 
to be $540,000, or $27,000 per airplane.
    The cost impact figures discussed above are 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 a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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-355-AD.

    Applicability: All Model BAe 146 series airplanes; and Model 
Avro 146-RJ series airplanes, as listed in British Aerospace Service 
Bulletin SB.57-56, dated September 2, 1999; certificated in any 
category; except those on which British Aerospace Modification 
HCM01307A or HCM01307B [Reference Repair Instruction (R.I.L. 
HC571H9033)] has been accomplished.

    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 (c) 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 increased loads on the upper wing skin due to 
looseness of the stringer fittings and bolts at Ribs 0 and 2 of the 
wings, which could result in reduced structural integrity of the 
wings, accomplish the following:

Inspections and Modification

    (a) Prior to the accumulation of 14,000 total flight cycles, or 
within 4,000 flight cycles after the effective date of this AD, 
whichever occurs later: Perform a detailed visual inspection of the 
stringers and a torque check of the Jo-bolts at Ribs 0 and 2 of the 
wings for discrepancies (including loose Jo-bolts and stringer crown 
fittings, fretting of fittings and stringers, and cracking or damage 
of attachments); in accordance with British Aerospace Service 
Bulletin SB.57-56, dated September 2, 1999.
    (1) If no discrepancy is found, or, if 1, 2, or 3 loose Jo-bolts 
are found per rib side and no loose crown (dagger) fittings are 
found (Category 1 or 2, as specified in Table 2 of paragraph D. 
``Compliance'' of the service bulletin), accomplish the actions 
required in paragraphs (a)(1)(i) and (a)(1)(ii) of this AD.
    (i) Repeat the inspection thereafter at the applicable times 
specified in Table 2, until accomplishment of the actions required 
by paragraph (a)(1)(ii).
    (ii) Prior to accumulation of 40,000 total flight cycles, or 
within 4,000 flight cycles after the effective date of this AD, 
whichever occurs later: Modify all stringer crown fittings at Ribs 0 
and 2 of the wings (including inspections, repairs, and installation 
of oversize interference fit fasteners per R.I.L. HC571H9033) in 
accordance with the service bulletin, except as required by 
paragraph (b) of this AD. This modification terminates the 
requirements of this AD.
    (2) If any other discrepancy is found, as specified in Table 2 
(Categories 3 through 6): At the applicable times specified in Table 
2, repeat the inspection thereafter, and modify all crown fittings 
at Ribs 0 and 2 of the wings (including inspections, repairs, and 
installation of oversize interference fit fasteners per R.I.L. 
HC571H9033); in accordance with the service bulletin, except as 
required by paragraph (b) of this AD. This

[[Page 39833]]

modification terminates the requirements of this AD.

    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.''

Approved Repairs

    (b) Where British Aerospace Service Bulletin SB.57-56, dated 
September 2, 1999, specifies to contact the manufacturer for a 
repair, prior to further flight, repair in accordance with a method 
approved by either the Manager, International Branch, ANM-116, FAA, 
Transport Airplane Directorate; or the Civil Aviation Authority of 
the United Kingdom (or its delegated agent). For a repair method to 
be approved by the Manager, International Branch, ANM-116, as 
required by this paragraph, the Manager's approval letter must 
specifically reference this AD.

Alternative Methods of Compliance

    (c) 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 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

    (d) Special flight permits may be issued in accordance with 
Secs. 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 004-09-99.


    Issued in Renton, Washington, on June 22, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-16359 Filed 6-27-00; 8:45 am]
BILLING CODE 4910-13-U