[Federal Register Volume 62, Number 31 (Friday, February 14, 1997)]
[Proposed Rules]
[Pages 6888-6890]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-3691]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-168-AD]
RIN 2120-AA64
Airworthiness Directives; Jetstream Model 4101 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 4101
airplanes. This proposal would require repetitive detailed visual
inspections to detect cracks on frame 179 at the attachment bracket for
the door restraint cable, and various follow-on actions. This proposal
also would require installation of new doublers and stress pads on
frame 179, which would terminate the repetitive inspections. This
proposal is prompted by reports of cracks in frame 179 of the fuselage
at the attachment bracket for the door restraint cable on in-service
airplanes due to improper rigging of the door restraint system. The
actions specified by the proposed AD are intended to prevent such
cracking, which could result in structural failure of the fuselage and
consequent rapid decompression of the pressurized section of the
fuselage.
DATES: Comments must be received by March 27, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-168-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 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
[[Page 6889]]
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-168-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-168-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 4101 airplanes.
The CAA advises that it has received reports of cracks in frame 179 of
the fuselage at the attachment bracket for the door restraint cable on
these in-service airplanes. The existing design of the door restraint
cable will not withstand continuous high loads that are induced by
improper rigging of the door restraint system. Cracking in frame 179 of
the fuselage, if not detected and corrected, could result in structural
failure of the fuselage and consequent rapid decompression of the
pressurized section of fuselage.
Explanation of Relevant Service Information
Jetstream has issued Alert Service Bulletin J41-A53-024, dated
April 26, 1996, which describes procedures for performing repetitive
detailed visual inspections to detect cracks on frame 179 at the
attachment bracket for the door restraint cable, and various follow-on
actions. (These follow-on actions include performing a test to verify
proper adjustment of the restraint cable, and correcting any
discrepancy.) For cases where no cracks are detected during inspection,
the alert service bulletin also describes procedures for installation
of new doublers and stress pads on frame 179, which would eliminate the
need for repetitive inspections. The CAA classified this alert service
bulletin as mandatory and issued British airworthiness directive 004-
04-96 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 repetitive detailed
visual inspections to detect cracks on frame 179 at the attachment
bracket for the door restraint cable, and various follow-on actions.
The proposed AD also would require installation of new doublers and
stress pads on frame 179, which would constitute terminating action for
the repetitive inspection requirements. The inspection, various follow-
on actions, and installation would be required to be accomplished in
accordance with the alert service bulletin described previously. If any
crack is detected during any visual inspection, the repair would be
required to be accomplished in accordance with a method approved by the
FAA.
Cost Impact
The FAA estimates that 49 Jetstream Model 4101 airplanes of U.S.
registry would be affected by this proposed AD.
The proposed inspection would take approximately 2 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the inspection proposed by
this AD on U.S. operators is estimated to be $5,880, or $120 per
airplane, per inspection cycle.
The proposed installation would take approximately 8 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
Required parts would be supplied by the manufacturer at no cost to the
operators. Based on these figures, the cost impact of the installation
proposed by this AD on U.S. operators is estimated to be $23,520, or
$480 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) 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.
[[Page 6890]]
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Jetstream Aircraft Limited: Docket 96-NM-168-AD.
Applicability: Model 4101 airplanes, constructors numbers 41004
through 41086 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 (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 cracking in frame 179 of the fuselage, which could
result in structural failure of the fuselage and consequent rapid
decompression of the pressurized section of the fuselage, accomplish
the following:
(a) Prior to the accumulation of 3,000 total flight cycles, or
within 300 flight cycles after the effective date of this AD,
whichever occurs later, perform a detailed visual inspection to
detect cracks on frame 179 at the attachment bracket for the door
restraint cable, in accordance with Part 1 of the Accomplishment
Instructions of Jetstream Alert Service Bulletin J41-A53-024, dated
April 26, 1996.
(1) If no crack is detected, repeat the visual inspection
thereafter at intervals not to exceed 1,000 flight cycles. After
each inspection, perform the actions specified in paragraph (c) of
this AD.
(2) If any crack is detected, prior to further flight, repair it
in accordance with a method approved by the Manager, Standardization
Branch, ANM-113, FAA, Transport Airplane Directorate. After repair,
perform the actions specified in paragraph (c) of this AD.
(b) Within 24 months after the effective date of this AD,
perform the visual inspection specified in paragraph (a) of this AD
in accordance with Part 2 of the Accomplishment Instructions of
Jetstream Alert Service Bulletin J41-A53-024, dated April 26, 1996;
and accomplish the applicable follow-on actions specified in
paragraph (b)(1) or (b)(2) of this AD.
(1) If no crack is detected, prior to further flight, install
new doublers and stress pads on frame 179 in accordance with the
alert service bulletin. Immediately after installation, perform the
actions specified in paragraph (c) of this AD. Accomplishment of
these actions constitutes terminating action for the repetitive
inspection requirements of paragraphs (a)(1) of this AD.
(2) If any crack is detected, prior to further flight, repair it
in accordance with a method approved by the Manager, Standardization
Branch. Prior to further flight following accomplishment of the
repair, install new doublers and stress pads on frame 179 in
accordance with the alert service bulletin; and then perform the
actions specified in paragraph (c) of this AD. Accomplishment of
these actions constitutes terminating action for the repetitive
inspection requirements of paragraphs (a)(1) of this AD.
(c) Prior to further flight following accomplishment of the
actions as specified in paragraph (a)(1), (a)(2), (b)(1), or (b)(2)
of this AD, perform a test to verify proper adjustment of the
restraint cable, in accordance with the alert service bulletin. If
the restraint cable has been improperly adjusted, prior to further
flight, correct the discrepancy in accordance with the alert service
bulletin.
(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. 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.
(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 February 5, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-3691 Filed 2-13-97; 8:45 am]
BILLING CODE 4910-13-U