[Federal Register Volume 61, Number 156 (Monday, August 12, 1996)]
[Proposed Rules]
[Pages 41757-41759]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-20430]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-139-AD]
RIN 2120-AA64
Airworthiness Directives; Jetstream Model BAe ATP 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 Jetstream Model BAe ATP
airplanes. This proposal would require repetitive inspections of the
ram air inlet ducts for structural integrity and security of fasteners,
and repairs, if necessary. This proposal also provides an optional
terminating modification for the repetitive inspections. This proposal
is prompted by a report of the separation of a ram air inlet duct from
the airplane during flight. The actions specified by the proposed AD
are intended to prevent such separation, which could pose a hazard to
persons or property on the ground.
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-139-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 Jetstream Aircraft, Inc., P.O. Box 16029, Dulles
International Airport, Washington, DC 20041-6029. This information may
be examined at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2148; 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 numbers
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-139-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-139-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 Jetstream Model BAe ATP
airplanes. The CAA advises that the ram air inlet duct base plate
flanges can delaminate and allow the screws fastening the ducts to the
airplane to pull through the duct base plate. These conditions, if not
corrected, could result in the separation of a duct from the airplane
during flight, which poses a hazard to persons or property on the
ground.
[[Page 41758]]
Explanation of Relevant Service Information
Jetstream has issued Service Bulletin BAe ATP-21-36, dated January
3, 1996, which describes procedures for inspecting the left and right
ram air inlet ducts, to detect if the duct base plate flange has
delaminated and the screws fastening the ducts to the airplane are
pulling through the duct base plate; this service bulletin also
describes procedures for repairing these discrepancies using new bolts
and washers. The CAA classified this service bulletin as mandatory and
issued CAA Airworthiness Directive 003-01-96 in order to assure the
continued airworthiness of these airplanes in the United Kingdom.
In addition, Jetstream has issued Service Bulletin BAe ATP-21-37,
dated January 23, 1996, which describes a ram air inlet duct
modification that terminates the need to perform required repetitive
duct inspections and repairs. This modification, which would prevent
the duct from separating from the airplane, requires the bolting of
reinforcing plates to the base flange of the duct. The CAA classified
this service bulletin as optional.
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 the inspection of
the airplane's left and right ram air inlet ducts to determine whether
the duct base plate flange has delaminated and the screws fastening
these ducts have pulled through the duct base plate; and would require
repair, if necessary. Thereafter, the proposed AD also would require
repetitive inspections and repairs, if necessary, unless an optional
terminating action is performed. The actions would be required to be
accomplished in accordance with the service bulletins described
previously.
Cost Impact
The FAA estimates that 10 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 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
$600 per inspection, or $60 per airplane, per inspection.
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 elect to accomplish the optional terminating
modification provided in this proposal, it would require approximately
1.5 work hours to accomplish, at an average labor rate of $60 per work
hour. (This work hour figure does not include the time necessary for
sealant to cure.) The cost of required parts would be nominal and could
be produced locally from standard materials. Based on these figures,
the cost impact of the proposed optional terminating modification on
U.S. operators is estimated to be $60 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:
Jetstream Aircraft, Ltd. (Formerly British Aerospace Commercial
Aircraft, Limited): Docket 96-NM-139-AD.
Applicability: Model BAe ATP airplanes having constructor
numbers 2002 through 2063 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
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 (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 the separation of the ram air inlet duct from the
airplane, accomplish the following:
(a) Prior to the accumulation of 50 flight hours after the
effective date of this AD, inspect the left and right ram air inlet
ducts to determine whether the duct base plate flange has
delaminated and the screws fastening the duct have pulled through
the duct base plate, in accordance with Jetstream BAe ATP Service
Bulletin ATP-21-36, dated January 3, 1996.
(1) If no discrepancy is detected, repeat the inspection
thereafter at intervals not to exceed 250 flight hours.
(2) If any discrepancy is detected, prior to further flight,
repair in accordance with the service bulletin. Thereafter, repeat
the inspection at intervals not to exceed 250 flight hours.
(b) Accomplishment of the modification of the ram air inlet
ducts in accordance with
[[Page 41759]]
Jetstream BAe ATP Service Bulletin ATP-21-37, dated January 23 ,
1996, constitutes terminating action for the repetitive inspections
required by paragraph (a) of this AD.
(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, 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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(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.
Issued in Renton, Washington, on August 6, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-20430 Filed 8-9-96; 8:45 am]
BILLING CODE 4910-13-U
