[Federal Register Volume 59, Number 85 (Wednesday, May 4, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-10643]
[[Page Unknown]]
[Federal Register: May 4, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-NM-25-AD]
Airworthiness Directives; Jetstream Aircraft Limited 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 inspections to detect damage of
the ball bearings in the aileron quadrants, replacement of damaged ball
bearings with new ball bearings, and adjustment to the secondary stops.
This action would require installation of new swivel bearings in the
aileron quadrants, which would terminate the inspection requirement.
This proposal is prompted by the development of a modification that
eliminates the need to inspect repetitively. The actions specified by
the proposed AD are intended to prevent failure of the bearings in the
aileron quadrants, which could result in reduced controllability of the
airplane.
DATES: Comments must be received by June 29, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-25-AD, 1601 Lind Avenue SW., Renton,
Washington 98055-4056. Comments may be inspected at this location
between 9 a.m. and 3 p.m., Monday through Friday, except Federal
holidays.
The service information referenced in the proposed rule may be
obtained from Jetstream Aircraft, Incorporated, 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) 227-1320.
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 94-NM-25-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. 94-NM-25-AD, 1601 Lind Avenue SW., Renton, Washington 98055-
4056.
Discussion
On March 3, 1994, the FAA issued AD 93-25-10, Amendment 39-8849 (59
FR 11531, March 11, 1994), applicable to certain Jetstream Model 4101
airplanes, to require inspections to detect damage of the ball bearings
in the aileron quadrants, replacement of damaged ball bearings with new
ball bearings, and adjustment to the secondary stops. That action was
prompted by a report that an in-flight failure of a ball bearing in a
quadrant in the pilot's aileron control system caused abnormal backlash
of the pilot's aileron control. The requirements of that AD are
intended to prevent reduced controllability of the airplane.
Since the issuance of that AD, Jetstream has developed new swivel
bearings that allow greater swivel action, which would significantly
decrease the likelihood of abnormal backlash of the aileron control due
to bearing failure. Bearing failure in the aileron quadrants, if not
corrected, could result in reduced controllability of the airplane.
Jetstream has issued Service Bulletin J41-27-027, dated January 17,
1994, that describes procedures for installation of swivel bearings in
the left and right aileron quadrants (Modification JM41307A).
Jetstream has also issued Revision 2 of Service Bulletin J41-A-27-
026, dated January 17, 1994. The inspection procedures described in
this revision are identical to those described in Revision 1 of the
service bulletin (which was referenced in AD 93-25-10). The only change
effected by Revision 2 is to reference the modification described in
Service Bulletin J41-27-027 as terminating action for the inspections
of the bearings in the aileron quadrants and adjustment to the
secondary stops described in Service Bulletin J41-A-27-026. The CAA
classified this service bulletin as mandatory in order to assure the
continued airworthiness of these airplanes in the United Kingdom.
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 and the
applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, the Civil Aviation Authority (CAA),
which is the airworthiness authority for the United Kingdom, 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.
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 93-25-10 to
require installation of new swivel bearings in the left and right
aileron quadrants (Modification JM41307A) as terminating action for the
currently required inspections. The actions would be required to be
accomplished in accordance with the service bulletins described
previously.
Paragraphs (a) and (b) of this proposal have been revised to
reference Revision 2 of Service Bulletin J41-A-27-026, dated January
17, 1994, as an additional source of service information for
accomplishing the inspections of the bearings in the aileron quadrants
and adjustment to the secondary stops.
The FAA estimates that 8 airplanes of U.S. registry would be
affected by this proposed AD.
The inspections that were previously required by AD 93-25-10, and
retained in this proposal, take approximately 1 work hour per airplane
to accomplish, at an average labor rate of $55 per work hour. Based on
these figures, the total cost impact of these inspection requirements
on U.S. operators is estimated to be $440, or $55 per airplane, per
inspection cycle.
The adjustment to the secondary stops that were previously required
by AD 93-25-10, and retained in this proposal, take approximately 1
work hour per airplane to accomplish, at an average labor rate of $55
per work hour. Based on these figures, the total cost impact of this
adjustment requirement on U.S. operators is estimated to be $440, or
$55 per airplane. The FAA estimates that all affected U.S. operators
have already accomplished this action; therefore, the future cost
impact of this requirement is minimal.
The installation of new swivel bearings (Modification JM41307A)
that would be required by this proposal would take approximately 10
work hours per airplane to accomplish, at an average labor rate of $55
per work hour. Required parts would be provided by the manufacturer at
no cost to the operator. Based on these figures, the total cost impact
of the modification requirement of this proposal on U.S. operators is
estimated to be $4,400, or $550 per airplane.
The total 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.
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 14
CFR part 39 of the Federal Aviation Regulations as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-8849 (59 FR
11531, March 11, 1994), and by adding a new airworthiness directive
(AD), to read as follows:
Jetstream Aircraft Limited: Docket 94-NM-25-AD. Supersedes AD 93-25-
10, Amendment 39-8849.
Applicability: Model 4101 airplanes having constructors numbers
41004 and subsequent on which Modification JM41307A or JM41307B has
not been installed previously; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent failure of the bearings in the aileron quadrants,
which could result in reduced controllability of the airplane,
accomplish the following:
(a) Within 7 days after March 28, 1994 (the effective date of AD
93-25-10, Amendment 39-8849), perform a detailed visual inspection
to detect damage of the bearings in the aileron quadrant in the
pilot's and co-pilot's aileron control, in accordance with Jetstream
Aircraft Limited Alert Service Bulletin J41-A-27-026, Revision 1,
dated December 7, 1993; or Revision 2, dated January 17, 1994.
(1) If no damaged bearing is found, repeat the inspection,
thereafter, at intervals not to exceed 7 days.
(2) If any damaged bearing is found, prior to further flight,
replace the damaged bearing with a new bearing in accordance with
the service bulletin, and repeat the inspection, thereafter, at
intervals not to exceed 7 days.
Note 1: Paragraph (a) of this AD restates the requirement for an
initial and repetitive inspections contained in paragraph (a) of AD
93-25-10. Therefore, for operators that have previously accomplished
at least the initial inspection in accordance with AD 93-25-10,
paragraph (a) of this AD requires that the next scheduled inspection
be performed within 7 days after the last inspection performed in
accordance with paragraph (a) of AD 93-25-10.
(b) Within 7 days after March 28, 1994 (the effective date of AD
93-25-10, Amendment 39-8849), adjust the aileron secondary stop in
the pilot's and co-pilot's aileron control system in accordance with
Jetstream Aircraft Limited Alert Service Bulletin J41-A-27-026,
Revision 1, dated December 7, 1993; or Revision 2, dated January 17,
1994.
Note 2: Paragraph (b) of this AD restates the requirement to
adjust the aileron secondary stop contained in paragraph (b) of AD
93-25-10. As allowed by the phrase ``unless accomplished
previously,'' if that requirement of AD 93-25-10 has been
accomplished previously, this AD does not require that it be
repeated.
(c) Within 7 days after March 28, 1994 (the effective date of AD
93-25-10, Amendment 39-8849), revise the Abnormal Procedures Section
of the FAA-approved Airplane Flight Manual (AFM) to include the
following. This may be accomplished by inserting a copy of this AD
in the AFM.
``Where abnormal aileron control backlash is experienced by one
pilot, the other pilot should assume control of the aircraft without
using the disconnect facility. The disconnect facility should only
be used in accordance with published procedures in cases of control
restrictions or jamming.''
Note 3: Paragraph (c) of this AD restates the requirement for an
AFM revision contained in paragraph (c) of AD 93-25-10. As allowed
by the phrase ``unless accomplished previously,'' if that
requirement of AD 93-25-10 has been accomplished previously, this AD
does not require that it be repeated.
(d) Within 180 hours time-in-service after the effective date of
this AD, install new swivel bearings in the left and right aileron
quadrants (Modification JM41307A) in accordance with Jetstream
Service Bulletin J41-27-027, dated January 17, 1994. Accomplishment
of this modification constitutes terminating action for the
requirements of this AD. The AFM revision required by paragraph (c)
of this AD may be removed following accomplishment of this
modification.
(e) 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 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(f) Special flight permits may be issued in accordance with
Federal Aviation Regulations (FAR) 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 28, 1994.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-10643 Filed 5-3-94; 8:45 am]
BILLING CODE 4910-13-U
