[Federal Register Volume 63, Number 156 (Thursday, August 13, 1998)]
[Proposed Rules]
[Pages 43351-43353]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-21714]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-235-AD]
RIN 2120-AA64
Airworthiness Directives; British Aerospace Model Avro 146-RJ85A
and RJ100A Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain British Aerospace Model
Avro 146-RJ85A and RJ100A series airplanes. This proposal would require
a one-time inspection for evidence of machining (undercutting) into the
web of the integral stringers of the bottom skin of the wings, and
corrective actions, if necessary. 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 reduced wing strength and stiffness, and the onset
of premature fatigue cracking, which could result in reduced structural
integrity of the airplane.
DATES: Comments must be received by September 14, 1998.
[[Page 43352]]
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-235-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 98-NM-235-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. 98-NM-235-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 Avro 146-RJ85A
and RJ100A series airplanes. The CAA advises that, during the
production of certain airplanes, the web of the integral stringers of
the bottom skin of the wings may have been produced with unnecessary
undercuts. These unnecessary undercuts may have undersized all the webs
of the integral stringers between ribs 2 to 18. This condition, if not
corrected, could result in reduced wing strength and stiffness, and the
onset of premature fatigue cracking, which could result in reduced
structural integrity of the airplane.
Explanation of Relevant Service Information
The manufacturer has issued British Aerospace Service Bulletin
SB.57-55, dated April 27, 1998, which describes procedures for a one-
time detailed visual inspection for evidence of machining
(undercutting) into the web of the integral stringers, between ribs 2
and 18, of the bottom skin of the wings, and corrective actions, if
necessary. The corrective actions include measuring the web of the
integral stringers if any machining (undercutting) is detected, and
repair, if necessary. Accomplishment of the action specified in the
service bulletin is intended to adequately address the identified
unsafe condition. The CAA classified this service bulletin as mandatory
to assure the continued airworthiness of these airplanes in the United
Kingdom.
FAA's 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 accomplishment of
the actions specified in the service bulletin described previously,
except as described below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, although the service bulletin specifies
that the manufacturer may be contacted for disposition of certain
machining (undercutting) 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 5 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 16 work
hours per airplane to accomplish the proposed inspection, 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
$4,800, or $960 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
[[Page 43353]]
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 98-NM-235-AD.
Applicability: Model Avro 146-RJ85A and RJ100A series airplanes,
as listed in British Aerospace Service Bulletin SB.57-55, dated
April 27, 1998, 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 (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 prevent reduced wing strength and stiffness, and the onset of
premature fatigue cracking, which could result in reduced structural
integrity of the airplane, accomplish the following:
(a) Within 6 months after the effective date of this AD, perform
a one-time detailed visual inspection for evidence of machining
(undercutting) into the web of the integral stringers of the bottom
skin of the wings, in accordance with British Aerospace Service
Bulletin SB.57-55, dated April 27, 1998.
(1) If no machining into the web is detected, no further action
is required by this AD.
(2) If any machining into the web is detected, prior to further
flight, measure the thickness of the web of the integral stringer in
accordance with the service bulletin.
(i) If the web thickness is 0.099 inch or more, no further
action is required by this AD.
(ii) If the web thickness is less than 0.099 inch, prior to
further flight, repair in accordance with a method approved by
either the Manager, International Branch, ANM-116, FAA, Transport
Directorate, or the Civil Aviation Authority (or its delegated
agent).
(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, 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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(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 August 7, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-21714 Filed 8-12-98; 8:45 am]
BILLING CODE CODE 4910-13-U
