[Federal Register Volume 61, Number 190 (Monday, September 30, 1996)]
[Rules and Regulations]
[Pages 50994-50995]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-24651]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-49-AD; Amendment 39-9772; AD 96-20-06]
RIN 2120-AA64


Airworthiness Directives; Jetstream Model 4101 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes 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 amendment requires installation of a new 
landing gear control unit. This amendment also expands the 
applicability of the existing AD to include additional airplanes. The 
actions specified by this AD are intended to prevent uncommanded 
retraction of a landing gear, which could adversely affect airplane 
controllability.

DATES: Effective November 4, 1996.
    The incorporation by reference of Jetstream Service Bulletin J41-
32-044, dated September 22, 1995, listed in the regulations is approved 
by the Director of the Federal Register as of November 4, 1996.
    The incorporation by reference of Jetstream Alert Service Bulletin 
J41-A32-042, dated April 13, 1995 listed in the regulations was 
approved previously by the Director of the Federal Register as of June 
14, 1995 (60 FR 28035, May 30, 1995).

ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 95-09-03, 
amendment 39-9241 (60 FR 28035, May 30, 1995), which is applicable to 
certain Jetstream Model 4101 airplanes, was published in the Federal 
Register on April 29, 1996 (61 FR 18707). The action proposed to 
supersede AD 95-09-03. For those airplanes subject to AD 95-09-03, it 
proposed to 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 proposed 
to require installation of a new improved landing gear control unit.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposed Rule

    One commenter supports the proposed rule.

Request to Limit Applicability of Proposed Rule

    One commenter questions why the proposed rule requires Jetstream 
Modification JM41490 (modification of the cable of the landing gear 
control unit) to be accomplished on the additional airplanes that have 
been included in the applicability of the proposed rule. The commenter 
states that this modification was installed on airplanes having 
constructor numbers 41052 and subsequent at the manufacturer's facility 
prior to delivery. Therefore, those airplanes should not be subject to 
the requirement for that modification.
    The FAA points out that Modification JM41490 (which is described in 
Jetstream Alert Service Bulletin J41-A32-042) is required by AD 95-09-
03 to be accomplished on Model 4101 airplanes having constructor 
numbers 41001 through 41046 inclusive, and 41048 through 41052 
inclusive. That requirement is specified in paragraph (a) of AD 95-09-
03. Paragraph (a) of this new AD merely restates the requirements of 
paragraph (a) of AD 95-09-03. It clearly indicates that it is 
applicable only to those same airplanes that were subject to AD 95-09-
03; no new, additional airplanes are subject to the requirements of 
that paragraph. Further, airplanes on which those actions have been 
performed previously, do not have to be modified in accordance with 
that paragraph a second time.

Request to Verify Parts Availability

    One commenter states that it has information that the manufacturer 
has been unable to produce the landing gear control units at the 
originally planned rate. The commenter requests that the FAA verify 
with the manufacturer that the landing gear control units required by 
paragraph (b) of the proposed rule will be available for installation 
within the proposed compliance time of six months.
    The FAA has verified with the manufacturer that there should be no 
delay in the manufacturing of those parts. Therefore, the compliance 
time of six months for this AD will remain unchanged.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

Cost Impact

    There are approximately 44 Jetstream Model 4101 airplanes of U.S. 
registry that will be affected by this AD.
    The actions that are currently required by AD 95-09-03, and 
retained in this 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 is required by this new AD will 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

[[Page 50995]]

cost impact on U.S. operators of the new 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 this 
requirement of this AD action, and that no operator would accomplish 
that action in the future if this AD were not adopted.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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), 
amendment 39-9772, to read as follows:

96-20-06  Jetstream Aircraft Limited: Amendment 39-9772. 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 
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 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.
    (f) The inspection and modification shall be done in accordance 
with Jetstream Alert Service Bulletin J41-A32-042, dated April 13, 
1995. The installation shall be done in accordance with Jetstream 
Service Bulletin J41-32-044, dated September 22, 1995. The 
incorporation by reference of Jetstream Alert Service Bulletin J41-
A32-042, dated April 13, 1995, was approved previously by the 
Director of the Federal Register in accordance with 5 U.S.C. 552(a) 
and 1 CFR part 51 as of June 14, 1995 (60 FR 28035, May 30, 1995). 
The incorporation by reference of Jetstream Service Bulletin J41-32-
044, dated September 22, 1995, was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Jetstream Aircraft, Inc., P.O. Box 
16029, Dulles International Airport, Washington, DC 20041-6029. 
Copies may be inspected at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (g) This amendment becomes effective on November 4, 1996.

    Issued in Renton, Washington, on September 19, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-24651 Filed 9-27-96; 8:45 am]
BILLING CODE 4910-13-U