[Federal Register Volume 61, Number 156 (Monday, August 12, 1996)]
[Proposed Rules]
[Pages 41755-41757]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-20429]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-41-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Model BAe 146 Series 
Airplanes 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 series airplanes and certain Model Avro 146-RJ series airplanes. 
This proposal would require a one-time inspection to detect corrosion 
of the direction link subassembly of the main landing gear (MLG) 
assembly, and repair or replacement of the direction link subassembly 
with a serviceable unit, if necessary. This proposal is prompted by a 
report of failure of the direction link subassembly due to corrosion. 
The actions specified by the proposed AD are intended to prevent such 
failures, which can result in directional control problems of the 
airplane during landing.

DATES: Comments must be received by September 23, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-41-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 (206) 
227-2797; fax (206) 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 96-NM-41-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. 96-NM-41-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 
series airplanes and certain Model Avro 146-RJ series airplanes. The 
CAA advises that it has received a report of a failure of a direction 
link subassembly of the main landing gear (MLG). Investigation revealed 
that the direction link subassembly was not sealed adequately to 
protect it from moisture. Further investigation revealed that ingress 
of moisture resulted in heavy corrosion on the threads of the direction 
link tube and the eye ends; this led to the failure of the direction 
link subassembly. Such failure of the direction link subassembly, if 
not detected and corrected in a timely manner, could result in problems 
with the directional control of the airplane during landing.

[[Page 41756]]

Explanation of Relevant Service Information

    British Aerospace has issued Service Bulletin SB.32-143, dated 
August 22, 1995. This service bulletin describes procedures for a 
visual inspection to detect corrosion of the direction link subassembly 
of the MLG assembly, and repair or replacement of the direction link 
subassembly with a serviceable part, if necessary. The service bulletin 
also describes certain follow-on procedures (application of a jointing 
compound to the threads of the direction link tube) if light surface 
corrosion or no corrosion is detected. The service bulletin also refers 
to Messier-Dowty Service Bulletin 146-32-127, dated August 21, 1995, as 
an additional source of service information. The CAA classified the 
British Aerospace service bulletin as mandatory in order to assure the 
continued airworthiness of these airplanes in the United Kingdom.

FAAs Conclusions

    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.

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 a one-time visual 
inspection to detect corrosion of the direction link subassembly of the 
MLG assembly, and repair or replacement of the direction link 
subassembly with a serviceable part, if necessary. The proposed AD 
would also require certain follow-on procedures (application of a 
jointing compound to the threads of the direction link tube) if light 
surface corrosion is detected or if no corrosion is detected. The 
actions would be required to be accomplished in accordance with the 
British Aerospace service bulletin described previously.

Cost Impact

    The FAA estimates that 52 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 3 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 
cost impact of the proposed AD on U.S. operators is estimated to be 
$9,360, or $180 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.
    Should an operator be required to accomplish the replacement of the 
link subassembly, it would be accomplished concurrently with the 
required inspection and take approximately no more work hours than the 
inspection itself. Replacement parts would cost approximately $8,200 
per airplane. Based on these figures, the cost impact of any necessary 
replacement action is estimated to be $8,200 per airplane.

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 96-NM-41-AD.

    Applicability: All Model BAe 146 series airplanes and Model Avro 
146-RJ series airplanes, as listed in British Aerospace Service 
Bulletin SB.32-143, dated August 22, 1995; certificated in any 
category.

    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 (g) 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 failure of the direction link subassembly of the main 
landing gear (MLG), which could result in reduced directional 
control of the airplane during landing, accomplish the following:
    (a) For airplanes that have accumulated 8,000 or more landings 
on the MLG assembly as of the effective date of this AD, or on which 
the MLG assembly was manufactured or last overhauled within 4 years 
prior to the effective date of this AD: Perform a visual inspection 
to detect corrosion of the direction link subassembly of the MLG 
assembly at the later of the times specified in paragraph (a)(1) or 
(a)(2) of this AD, in accordance with British Aerospace Service 
Bulletin SB.32-143, dated August 22, 1995.

    Note 2: British Aerospace Service Bulletin SB.32-143, dated 
August 22, 1995, references Messier-Dowty Service Bulletin 146-32-
127, dated August 21, 1995, as an additional source of service 
information.

    (1) Prior to the accumulation of 12,000 total landings, or 
within 5 years since manufacture or last overhaul, whichever occurs 
first. Or
    (2) Prior to the accumulation of 400 landings on the MLG 
assembly after the effective date of this AD, or within 2 months

[[Page 41757]]

after the effective date of this AD, whichever occurs first.
    (b) For airplanes not subject to paragraph (a) of this AD: 
Perform a visual inspection to detect corrosion of the direction 
link subassembly of the MLG assembly at the later of the times 
specified in paragraph (b)(1) or (b)(2) of this AD, in accordance 
with British Aerospace Service Bulletin SB.32-143, dated August 22, 
1995.
    (1) Prior to the accumulation of 4,000 landings on the MLG 
assembly after the effective date of this AD. Or
    (2) Within 12 months after the effective date of this AD.
    (c) If no corrosion is found during the inspection required by 
paragraph (a) or (b) of this AD: Prior to further flight, perform 
the follow-on actions in accordance with British Aerospace Service 
Bulletin SB.32-143, dated August 22, 1995.

    Note 3: ``Follow-on actions,'' as specified in this AD, include 
applying jointing compound to the threads; in some case, restoring 
the cadmium plate; and applying sealant to the exposed threads and 
castellations on the direction link subassembly. These actions are 
described in detail in Messier-Dowty Service Bulletin 146-32-127, 
dated August 21, 1995.

    (d) If light surface corrosion, as defined in British Aerospace 
Service Bulletin SB.32-143, dated August 22, 1995, is detected 
during the inspection required by paragraph (a) of this AD: Prior to 
further flight, remove the corrosion and perform the follow-on 
actions in accordance with the service bulletin.
    (e) If any corrosion is found during the inspection required by 
paragraph (a) or (b) or this AD, and that corrosion is beyond the 
limits specified in British Aerospace Service Bulletin SB.32-143, 
dated August 22, 1995: Prior to further flight, replace the link 
subassembly in accordance with the service bulletin.
    (f) As of the effective date of this AD, no person shall install 
a MLG or directional link subassembly unless the inspection and 
necessary follow-on actions of the directional link subassembly 
specified in paragraphs (a), (b), (c), and (d) of this AD have been 
performed, in accordance with British Aerospace Service Bulletin 
SB.32-143, dated August 22, 1995.
    (g) 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 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.

    (h) 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 August 6, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-20429 Filed 8-9-96; 8:45 am]
BILLING CODE 4910-13-U