[Federal Register Volume 63, Number 173 (Tuesday, September 8, 1998)]
[Proposed Rules]
[Pages 47445-47447]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-24060]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-129-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 a one-time measurement to determine the thickness of the outer
links of the side stays of the main landing gear (MLG), and corrective
actions, if necessary. This proposal also would provide for replacement
of a thin outer link with a new or serviceable part in lieu of certain
follow-on inspections. 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 cracking of the outer links of the side stays of
the MLG, which could result in increased braking distance during
landing, and consequent runway overrun.
DATES: Comments must be received by October 8, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-129-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:
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-129-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-129-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 it has
received a report of cracking on the shoulder of two outer links of a
side stay of the main landing gear (MLG). Investigation has revealed
that the insufficient thickness of the outer links on certain Model BAe
146 and Model Avro 146-RJ series airplanes causes them to be
susceptible to this type of cracking. In addition, this cracking may
have been aggravated by insufficient greasing of the spherical bearing,
which could result in increased stress on the side stay when the gear
is in transit. Such cracking, if not corrected, could result in
increased braking distance during landing, and consequent runway
overrun.
Explanation of Relevant Service Information
The manufacturer has issued British Aerospace Service Bulletin
SB.32-144, dated December 11, 1996, which describes procedures for a
one-time measurement to determine the thickness of the outer links of
the side stays of the MLG. The measurement involves placing a profile
gauge over the thinnest section of the outer link profile. For outer
links on which a profile gauge slips over the profile, the service
bulletin also describes procedures for follow-on repetitive detailed
visual inspections to detect cracking of the outer links, and
replacement of any cracked outer link with a new or serviceable part.
The British Aerospace service bulletin references Messier-Dowty
Service Bulletin 146-32-128, dated December 6, 1996, as an additional
source of service information for accomplishment of the measurement.
Accomplishment of the actions specified in the service bulletins is
intended to adequately address the identified unsafe condition. The CAA
approved Messier-Dowty Service Bulletin 146-32-128, dated December 6,
1996; classified British Aerospace Service Bulletin SB.32-144, dated
December 11, 1996, as mandatory; and issued British airworthiness
directive 005-12-96 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
[[Page 47446]]
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 British Aerospace service bulletin
described previously, except as discussed below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, unlike the procedures described in
Messier-Dowty Service Bulletin 146-32-128 and British Aerospace Service
Bulletin SB.32-144, this proposed AD would not permit further flight if
cracks are detected in the outer links of the side stays of the MLG.
The FAA has determined that, because of the safety implications and
consequences associated with such cracking, any subject outer link that
is found to be cracked must be replaced prior to further flight.
In addition, operators should note that, for airplanes on which the
profile gauge slips over the top edge of the outer link profile, the
service bulletins do not describe a terminating action for the follow-
on repetitive inspections to detect cracking of the outer links.
However, this proposed AD would allow replacement of a thin outer link
with a new or serviceable part in lieu of the follow-on inspections.
Cost Impact
The FAA estimates that 37 airplanes of U.S. registry would be
affected by this proposed AD. It would take approximately 1 work hour
per airplane to accomplish the proposed measurement, at an average
labor rate of $60 per work hour. Required parts would be supplied by
the manufacturer at no cost to operators. Based on this figure, the
cost impact of the measurement proposed by this AD on U.S. operators is
estimated to be $2,220, or $60 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 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-129-AD.
Applicability: Model BAe 146 and Model Avro 146-RJ series
airplanes, equipped with side stays of the main landing gear (MLG)
having part numbers (P/N) listed in Messier-Dowty Service Bulletin
146-32-128, dated December 6, 1996; 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 (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 cracking of the outer links of the side stays of the
main landing gear (MLG), which could result in increased braking
distance during landing, and consequent runway overrun, accomplish
the following:
(a) Within 500 landings or 60 days after the effective date of
this AD, whichever occurs later, perform a one-time measurement to
determine the thickness of the outer links of the side stays of the
MLG, in accordance with British Aerospace Service Bulletin SB.32-
144, dated December 11, 1996.
Note 2: The British Aerospace service bulletin references
Messier-Dowty Service Bulletin 146-32-128, dated December 6, 1996,
as an additional source of service information for accomplishment of
the measurement.
(1) If the profile gauge does not slip over the top edge of the
outer link profile, no further action is required by this AD.
(2) If the profile gauge slips over the top edge of the outer
link profile, prior to further flight, accomplish either paragraph
(a)(2)(i) or (a)(2)(ii) of this AD.
(i) Replace the outer link with a new or serviceable part in
accordance with the service bulletin. After replacement of the outer
link, no further action is required by this AD.
Note 3: For purposes of this AD, a ``serviceable'' outer link is
defined as an outer link that is not cracked and on which a profile
gauge does not slip over the top edge of the profile, as described
in the service bulletin.
(ii) Perform a detailed visual inspection to detect cracking of
the outer links of the side stays of the MLG, in accordance with the
service bulletin.
(A) If no cracking is detected, repeat the detailed visual
inspection thereafter at intervals not to exceed 4,000 landings.
(B) If any cracking is detected during any detailed visual
inspection required by this AD, prior to further flight, replace the
cracked outer link with a new or serviceable part in accordance with
the service bulletin. After replacement of the outer link, no
further action is required by this AD.
(b) As of the effective date of this AD, no person shall install
on any airplane a side stay of the MLG having a part number listed
in paragraph 1.A. of Messier-Dowty Service Bulletin 146-32-128,
dated December 6, 1996; unless the profile gauge does not slip over
the profile of the outer links of the side stay, as described in
British Aerospace Service Bulletin SB.32-144, dated December 11,
1996.
(c) An alternative method of compliance or adjustment of the
compliance time that
[[Page 47447]]
provides an acceptable level of safety may be used if approved by
the Manager, International Branch, ANM-116, 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, International Branch, ANM-
116.
Note 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(d) 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 5: The subject of this AD is addressed in British
airworthiness directive 005-12-96.
Issued in Renton, Washington, on September 1, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-24060 Filed 9-4-98; 8:45 am]
BILLING CODE 4910-13-P
