[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]
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