[Federal Register Volume 61, Number 83 (Monday, April 29, 1996)]
[Proposed Rules]
[Pages 18707-18709]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-10505]
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DEPARTMENT OF AGRICULTURE
DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-49-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 supersedure of an existing
airworthiness directive (AD), applicable to certain Jetstream Model
4101 airplanes, that currently requires inspection to determine the
number of hours time-in-service on the landing gear control unit, and
modification of the cable (electrical wiring circuit) of the landing
gear control unit. That AD was prompted by a report of failure of a
micro-switch in the landing gear control unit. This action would
require installation of a new landing gear control unit. This action
also would expand the applicability of the existing AD to include
additional airplanes. The actions specified by the proposed AD are
intended to prevent uncommanded retraction of a landing gear, which
could adversely affect airplane controllability.
DATES: Comments must be received by June 10, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-49-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,
[[Page 18708]]
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 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-49-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-49-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On May 18, 1995, the FAA issued AD 95-09-03, amendment 39-9241 (60
FR 28035, May 30, 1995), applicable to certain Jetstream Model 4101
airplanes, to require inspection to determine the number of hours time-
in-service on the landing gear control unit, and modification of the
cable (electrical wiring circuit) of the landing gear control unit.
That action was prompted by a report of failure of a micro-switch in
the landing gear control unit. The requirements of that AD are intended
to prevent uncommanded retraction of a landing gear, which could
adversely affect airplane controllability.
In the preamble to AD 95-09-03, the FAA indicated that modification
(Jetstream Modification JM41490) of the cable (electrical wiring
circuit) of the landing gear control unit was considered ``interim
action'' and that further rulemaking action was being considered. As a
follow-on action from that determination, the FAA is now proposing
additional, final action.
Explanation of Relevant Service Information
Since the issuance of AD 95-09-03, Jetstream has issued Service
Bulletin J41-32-044, dated September 22, 1995, which describes
procedures for installation of a new improved landing gear control
unit, identified as Modification JM41501. The procedures involve
installing a new landing gear control unit that has revised switching.
The new switching will prevent uncommanded landing gear retractions
caused by spurious signals from single switch failures.
The installation also involves revising certain wiring, which
includes removing cables installed in accordance with Jetstream
Modification JM41490. Additionally, the installation involves
reallocating a spare pin in the airplane connector to prevent the
operation of the old landing gear control unit in the event that one is
inadvertently installed.
Accomplishment of Modification JM41501 will positively address the
unsafe condition identified as uncommanded retraction of a main landing
gear.
In addition, the effectivity listing of this service bulletin
includes additional airplanes that were not previously affected by AD
95-09-03, and removes certain others.
The Civil Aviation Authority (CAA), which is the airworthiness
authority for the United Kingdom, classified this service bulletin as
mandatory 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 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 the Requirements of the 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 supersede AD 95-09-03. For
those airplanes subject to AD 95-09-03, it would continue to require an
inspection to determine the number of hours time-in-service on the
landing gear control unit, and modification of the cable (electrical
wiring circuit) of the landing gear control unit. For those airplanes
and certain others, it would require installation of a new improved
landing gear control unit. The actions would be required to be
accomplished in accordance with the Jetstream service bulletin
described previously.
The applicability of the proposed AD would include additional
airplanes that have been identified to be subject to the same unsafe
condition (an included in the effectivity listing of the Jetstream
service bulletin).
Cost Impact
There are approximately 44 Jetstream Model 4101 airplanes of U.S.
registry that would be affected by this proposed AD.
The actions that are currently required by AD 95-09-03, and
retained in this proposed AD, take approximately 7 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
The required parts are provided by the manufacturer at no cost to the
operator. Based on these figures, the cost impact on U.S. operators of
the actions currently required is estimated to be $18,480, or $420 per
airplane. The FAA has been advised that all affected U.S. operators
have accomplished these requirements; therefore, there is no future
cost impact of these requirements on current U.S. operators of these
airplanes.
The new installation that would be required by this proposed AD
would take approximately 6 work hours per airplane to accomplish, at an
average labor rate of $60 per work hour. Required parts would be
provided at no cost to the operator. Based on these figures, the cost
impact on U.S. operators of the proposed requirements of this AD is
estimated to be $15,840, or $360 per airplane. This cost impact figure
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.
[[Page 18709]]
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 removing amendment 39-9241 (60 FR
28035, May 30, 1995), and by adding a new airworthiness directive (AD),
to read as follows:
Jetstream Aircraft Limited: Docket 96-NM-49-AD. Supersedes AD 95-09-
03, Amendment 39-9241.
Applicability: Model 4101 airplanes, constructor numbers 41001
through 41073 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 (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 uncommanded retraction of the landing gear, which can
adversely affect airplane controllability, accomplish the following:
-
(a) For airplanes having constructor numbers 41001 through 41046
inclusive, and 41048 through 41052 inclusive; equipped with either
landing gear control unit part number 717701-1 or 717701-1 Mod A:
Within 8 hours time-in-service after June 14, 1995 (the effective
date of AD 95-09-03, amendment 39-9241), perform an inspection to
determine the number of hours time-in-service on the landing gear
control unit, in accordance with Jetstream Alert Service Bulletin
J41-A32-042, dated April 13, 1995. -
(1) For those airplanes on which the control unit has
accumulated less than 200 hours time-in-service: Prior to further
flight, modify the cable (electrical wiring circuit) of the landing
gear control unit in accordance with the alert service bulletin. -
(2) For those airplanes on which the control unit has
accumulated 200 hours or more time-in-service: Within 50 hours time-
in-service or within 7 days after June 14, 1995 (the effective date
of AD 95-09-03, amendment 39-9241), whichever occurs earlier, modify
the cable (electrical wiring circuit) of the landing gear control
unit in accordance with the alert service bulletin. -
(b) For airplanes having constructor numbers 41001 through 41073
inclusive: Within 6 months after the effective date of this AD,
install a new improved landing gear control unit and modify the
wiring, in accordance with Jetstream Service Bulletin J41-32-044,
dated September 22, 1995. -
(c) As of the effective date of this AD, no person shall install
a landing gear control unit having part number 717701-1 or 717701-1
Mod A, on any airplane. -
(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, 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 Manager, 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 April 23, 1996.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-10505 Filed 4-26-96; 8:45 am]
BILLING CODE 4910-13-P