AD 96-17-03

[Federal Register Volume 61, Number 157 (Tuesday, August 13, 1996)]
[Rules and Regulations]
[Pages 41955-41957]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-20427]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-192-AD; Amendment 39-9711; AD 96-17-03]
RIN 2120-AA64


Airworthiness Directives; Jetstream Model 4101 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Jetstream Model 4101 airplanes. This action 
requires an inspection to determine the serial number of the leg 
assemblies of the main landing gear (MLG), and replacement of defective 
pins with serviceable pins. This amendment is prompted by a report 
indicating that pins installed on certain leg assemblies of the MLG's 
were heat treated incorrectly during manufacture. The actions specified 
in this AD are intended to prevent failure of the pins due to incorrect 
heat treatment, and subsequent structural failure of the MLG.

DATES: Effective August 28, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 28, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before October 15, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-192-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    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 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.

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: 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 received a report indicating 
that certain torque arm pivot pins, drag brace attachment pins, and 
drag brace pivot pins installed on the leg assemblies of the main 
landing gears (MLG) on Model 4101 airplanes were heat treated 
incorrectly during manufacture. Such incorrect heat treatment of these 
pins could result in failure of the pins. This condition, if not 
corrected, could result in structural failure of the MLG.

Explanation of Relevant Service Information

    Jetstream has issued Service Bulletin J41-32-023, dated May 27, 
1996, which describes procedures for an inspection to determine the 
serial number of the left and right leg assemblies (shock strut and 
drag brace) of the MLG, and replacement of defective drag brace 
attachment pins, drag brace pivot pins, and torque arm pivot pins on 
certain leg assemblies with serviceable pins. The Jetstream service 
bulletin references APPH Precision Hydraulics Service Bulletin 
AIR83090-32-02, dated March 1996, as an additional source of service 
information. The APPH Precision Hydraulics service bulletin identifies 
the serial numbers of MLG leg assemblies on which defective pins are 
installed, and describes procedures for replacement of those pins with 
serviceable pins.
    The CAA classified the Jetstream service bulletin as mandatory and 
issued United Kingdom airworthiness directive 003-05-96, dated June 12, 
1996, 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

[[Page 41956]]

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 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, this AD is being issued to prevent failure of the 
pins on certain leg assemblies of the MLG due to incorrect heat 
treatment, and subsequent structural failure of the MLG. This AD 
requires an inspection to determine the serial number of the left and 
right leg assemblies (shock strut and drag brace) of the MLG, and 
replacement of defective drag brace attachment pins, drag brace pivot 
pins, and torque arm pivot pins on certain leg assemblies with 
serviceable pins. The actions are required to be accomplished in 
accordance with the Jetstream service bulletin described previously.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 96-NM-192-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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 adding the following new 
airworthiness directive:

96-17-03 Jetstream Aircraft Limited: Amendment 39-9711. Docket 96-
NM-192-AD.

    Applicability: Model 4101 airplanes; serial numbers 41060 and 
41071 through 41078 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 (b) 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 failure of the pins on certain leg assemblies 
of the main landing gear (MLG) due to incorrect heat treatment, and 
subsequent structural failure of the MLG, accomplish the following:
    (a) Within 30 days after the effective date of this AD, perform 
an inspection to determine the serial number of the left and right 
leg assemblies (shock strut and drag brace) of the MLG in accordance 
with Jetstream Service Bulletin J41-32-023, dated May 27, 1996.
    (1) If no leg assembly has a serial number that is identified in 
the service bulletin, no further action is required by this AD.
    (2) If any leg assembly has a serial number that is identified 
in the service bulletin, prior to further flight, replace the 
defective drag brace attachment pins, drag brace pivot pins, and 
torque arm pivot pins with serviceable pins, in accordance with the 
service bulletin.

    Note 2: The Jetstream service bulletin references APPH Precision 
Hydraulics Service Bulletin AIR83090-32-02, dated March 1996, as an 
additional source of service information for identification of the 
serial numbers of affected MLG leg assemblies, and for replacement 
of defective pins with serviceable pins.

    (b) 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.


[[Page 41957]]


    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (c) 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.
    (d) The actions shall be done in accordance with Jetstream 
Service Bulletin J41-32-023, dated May 27, 1996. This incorporation 
by reference 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.
    (e) This amendment becomes effective on August 28, 1996.

    Issued in Renton, Washington, on August 6, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-20427 Filed 8-12-96; 8:45 am]
BILLING CODE 4910-13-U