[Federal Register Volume 63, Number 76 (Tuesday, April 21, 1998)]
[Proposed Rules]
[Pages 19680-19682]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10483]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-86-AD]
RIN 2120-AA64
Airworthiness Directives; British Aerospace (Jetstream) Model
4100 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
(Jetstream) Model 4100 airplanes. This proposal would require an eddy
current conductivity test to measure the conductivity of the upper
splice plate of the wing, and follow-on 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 correct corrosion of the
upper splice plate of the wing, which could result in reduced
structural integrity of the airplane.
DATES: Comments must be received by May 21, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-86-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.
[[Page 19681]]
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-86-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-86-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 (Jetstream) Model 4100
airplanes. The CAA advises that it has received reports of exfoliation
corrosion of the upper splice plate of the wing on certain airplanes.
Investigation has revealed that the susceptibility to corrosion of the
upper splice plate is related to the conductivity of the material.
Because the manufacturer finds that such corrosion may be related to a
material batch problem, the corrosion is likely to be present or
develop on other airplanes with an upper splice plate made from the
same material. Corrosion on the upper splice plate of the wing, if not
corrected, could result in reduced structural integrity of the
airplane.
Explanation of Relevant Service Information
British Aerospace has issued Regional Aircraft Service Bulletin
J41-57-019, Revision 1, dated November 26, 1997, including Appendix 1,
which describes procedures for performing an eddy current conductivity
test to measure the conductivity of the upper splice plate of the wing.
If the conductivity of the upper splice plate of the wing is less than
35% of the International Aluminum and Copper Standards (IACS), follow-
on actions are required. The CAA approved this service bulletin.
British Aerospace also has issued Regional Aircraft Service
Bulletin J41-57-020, dated March 20, 1997, including Appendix 1 and
Appendix 2, which describes procedures for performing repetitive
detailed visual inspections, using a boroscope, to detect corrosion
along the full length of the upper splice plate of the wing; repairing
damage that is found to be within certain specified limits; and
replacing the existing upper splice plate with a new upper splice
plate, if necessary. Such replacement eliminates the need for the
repetitive inspections. The CAA classified this service bulletin as
mandatory and issued British airworthiness directive 005-03-97
(undated), in order 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 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 bulletins described previously,
except as discussed below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, although British Aerospace Regional
Aircraft Service Bulletin J41-57-020 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 the FAA.
Cost Impact
The FAA estimates that 54 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 1 work
hour per airplane to accomplish the proposed eddy current conductivity
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 $3,240, 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.
[[Page 19682]]
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 Jetstream Aircraft
Limited; British Aerospace (Commercial Aircraft) Limited]: Docket
98-NM-86-AD.
Applicability: Jetstream Model 4100 airplanes, constructor's
numbers 41004 through 41096 inclusive; 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 correct corrosion of the upper splice plate of the wing,
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
an eddy current conductivity test to measure the conductivity of the
upper splice plate of the wing, in accordance with British Aerospace
Regional Aircraft Service Bulletin J41-57-019, Revision 1, dated
November 26, 1997, including Appendix 1. If the conductivity
measurement is greater than or equal to 35.0% of the International
Aluminum and Copper Standards (IACS), no further action is required
by this AD.
(b) During the inspection required by paragraph (a) of this AD,
if the conductivity measurement is less than 35.0% of the IACS:
Prior to further flight, use a boroscope to perform a detailed
visual inspection to detect corrosion along the full length of the
upper splice plate of the wing, in accordance with British Aerospace
Regional Aircraft Service Bulletin J41-57-020, dated March 20, 1997,
including Appendix 1 and Appendix 2. Thereafter, repeat the
inspection at intervals not to exceed 1 year.
(1) During any inspection required by paragraph (b) of this AD,
if any corrosion is detected that is within the allowable limits
specified in the service bulletin: Accomplish the actions required
by paragraphs (b)(1)(i) and (b)(1)(ii) of this AD, at the times
specified in those paragraphs.
(i) Prior to further flight, repair the upper splice plate of
the wing in accordance with Appendix 2 of the service bulletin. And
(ii) Within 3 years after the detection of corrosion, replace
the upper splice plate of the wing with a new upper splice plate in
accordance with the service bulletin. Such replacement constitutes
terminating action for the requirements of this AD.
(2) During any inspection required by paragraph (b) of this AD,
if any corrosion is detected that is outside the allowable limits
specified in the service bulletin: Prior to further flight, repair
in accordance with a method approved by the Manager, International
Branch, ANM-116, FAA, Transport Airplane Directorate.
(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 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.
(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 3: The subject of this AD is addressed in British
airworthiness directive 005-03-97 (undated).
Issued in Renton, Washington, on April 15, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-10483 Filed 4-20-98; 8:45 am]
BILLING CODE 4910-13-U
