[Federal Register Volume 61, Number 167 (Tuesday, August 27, 1996)]
[Proposed Rules]
[Pages 44006-44008]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-21744]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-48-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 certain British Aerospace Model 
BAe 146 series airplanes and Model Avro 146-RJ series airplanes. This 
proposal would require inspections to detect leakage of hydraulic fluid 
from the lock jack assemblies of the main landing gear (MLG), and 
eventual replacement of those assemblies with new or serviceable 
assemblies. This proposal is prompted by reports of leakage of 
hydraulic fluid from lock jack assemblies due to a manufacturing 
forging defect that extends through the wall of the lock jack assembly. 
The actions specified by the proposed AD are intended to prevent 
leakage of hydraulic fluid from the lock jack assemblies of the MLG, 
which, in conjunction with a hot brake, could cause a fire in the MLG 
bay.

DATES: Comments must be received by October 7, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-48-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 Holding, 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,

[[Page 44007]]

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-48-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-48-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 certain British Aerospace Model BAe 146 
series airplanes and Model Avro 146-RJ series airplanes. The CAA 
advises that a batch of lock jack assemblies of the main landing gear 
(MLG) has been manufactured with a forging defect as a result of the 
use of defective material in the bodies of the lock jack assemblies. 
This defect extends through the wall of the lock jack assembly, and 
allows the lock jack assembly to leak hydraulic fluid. The discrepant 
lock jack assemblies are identifiable by serial number. Hydraulic fluid 
leaking from the lock jack assembly, occurring concurrently with a hot 
brake, could result in a fire in the MLG bay.
    The lock jack assemblies of the MLG installed on British Aerospace 
Model BAe 146 series airplanes are identical to those installed on 
British Aerospace Model Avro 146-RJ series airplanes; therefore, both 
of these models may be subject to this same unsafe condition.

Explanation of Relevant Service Information

    British Aerospace has issued Inspection Service Bulletin SB 32-103, 
Revision 1, dated February 22, 1991. This service bulletin describes 
procedures for identifying affected lock jack assemblies by serial 
number, and provides procedures to repetitively inspect certain of 
those assemblies to detect leakage of hydraulic fluid, and replace the 
assemblies with a new or serviceable assembly, if necessary. The 
service bulletin also describes procedures to eventually replace the 
lock jack assemblies with a new or serviceable assembly that does not 
require accomplishment of the inspections specified in this service 
bulletin. The CAA classified those procedures in this service bulletin 
as mandatory 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 the 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, this AD is being issued to prevent leakage of 
hydraulic fluid from the lock jack assemblies of the main landing gear 
(MLG), which, in conjunction with a hot brake, could cause a fire in 
the MLG bay. This AD would require an inspection to identify affected 
lock jack assemblies by serial number. This AD also would require 
repetitive inspections of certain lock jack assemblies to detect 
leakage of hydraulic fluid from the lock jack assemblies, and, if 
leakage is detected, replacement of the lock jack assemblies with new 
or serviceable assemblies. This AD also would require eventual 
replacement of the lock jack assemblies with new or serviceable 
assemblies. The actions would be required to be accomplished in 
accordance with the service bulletin described previously.

Cost Impact

    The FAA estimates that 52 airplanes of U.S. registry would be 
affected by this proposed AD.
    To accomplish the proposed inspections would take approximately 1 
work hour per airplane, per inspection, at an average labor rate of $60 
per work hour. Based on these figures, the cost impact of the proposed 
inspections on U.S. operators is estimated to be $3,120, or $60 per 
airplane, per inspection cycle.
    To accomplish the proposed replacement of the lock jack assembly 
would take approximately 1 work hour per airplane, at an average labor 
rate of $60 per work hour. Required parts would be provided by the 
manufacturer at no cost to the operators. Based on these figures, the 
cost impact of the proposed replacement on U.S. operators is estimated 
to be $3,120, or $60 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 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)

[[Page 44008]]

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 USC 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-48-AD.

    Applicability: Model BAe 146 series airplanes and Model Avro 
146-RJ series airplanes having lock jack assemblies of the main 
landing gear as listed in British Aerospace Inspection Service 
Bulletin SB 32-103, Revision 1, dated February 22, 1991; 
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 (d) 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 leakage of hydraulic fluid from the lock jack 
assemblies of the main landing gear (MLG), which, in conjunction 
with a hot brake, could cause a fire in the MLG bay; accomplish the 
following:
    (a) Within 30 days after the effective date of this AD, verify 
the serial number of all lock jack assemblies, part number 
104275001, of the MLG.

    Note 2: Verification may be accomplished by a review of 
appropriate records.

    (1) If no lock jack assembly has a serial number as listed in 
British Aerospace Inspection Service Bulletin SB 32-103, Revision 1, 
dated February 22, 1991, no further action is required by this 
paragraph.
    (2) If any lock jack assembly has a serial number as listed in 
British Aerospace Inspection Service Bulletin SB 32-103, Revision 1, 
dated February 22, 1991, prior to further flight, perform a visual 
inspection to detect any leakage of hydraulic fluid from the lock 
jack assembly, in accordance with the service bulletin.
    (i) If no leakage of hydraulic fluid is detected, thereafter, 
repeat the inspection at intervals not to exceed 30 days, until the 
requirements of paragraph (b) of this AD are accomplished.
    (ii) If any leakage of hydraulic fluid is detected, prior to 
further flight, replace the lock jack assembly with a new or 
serviceable unit that does not have one of those serial numbers, in 
accordance with the service bulletin.
    (b) Within 6 months after the effective date of this AD, replace 
any lock jack assembly having a serial number listed in British 
Aerospace Inspection Service Bulletin SB 32-103, Revision 1, dated 
February 22, 1991, with a new or serviceable assembly that does not 
have one of those serial numbers, in accordance with the service 
bulletin.
    (c) As of the effective date of this AD, no person shall install 
a lock jack assembly, having any serial number listed in British 
Aerospace Inspection Service Bulletin SB 32-103, Revision 1, dated 
February 22, 1991, on any airplane.
    (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 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.

    (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 August 20, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-21744 Filed 8-26-96; 8:45 am]
BILLING CODE 4910-13-U