[Federal Register Volume 61, Number 250 (Friday, December 27, 1996)]
[Rules and Regulations]
[Pages 68134-68135]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31605]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-271-AD; Amendment 39-9856; AD 96-25-13]
RIN 2120-AA64


Airworthiness Directives; Jetstream Model 4101 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Jetstream Model 4101 series airplanes, that 
requires a high frequency eddy current inspection to detect cracks of 
the boundary angle and joint angle of the rear pressure bulkhead, and 
repair, if necessary. This amendment also requires modification of the 
rear pressure bulkhead of the fuselage. This amendment is prompted by a 
report of fatigue cracking in the rear pressure bulkhead of the 
fuselage. The actions specified by this AD are intended to prevent such 
fatigue cracking, which could result in reduced structural integrity of 
the fuselage and, consequently, lead to the rapid decompression of the 
pressurized area of the airplane.

DATES: Effective January 31, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 31, 1997.

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) to include an airworthiness 
directive (AD) that is applicable to certain Jetstream Model 4101 
airplanes was published as a supplemental notice of proposed rulemaking 
in the Federal Register on October 31, 1996 (61 FR 56169). That action 
proposed to require a high frequency eddy current inspection to detect 
cracks of the boundary angle and joint angle of the rear pressure 
bulkhead, and repair, if necessary. That action also proposed to 
require modification of the rear pressure bulkhead of the fuselage.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received.
    The commenter supports the proposed rule.

[[Page 68135]]

Conclusion

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

Cost Impact

    The FAA estimates that 40 Model 4101 airplanes of U.S. registry 
will be affected by this AD, that it will take approximately 40 work 
hours per airplane to accomplish the required actions, and that the 
average labor rate is $60 per work hour. Required parts will be 
supplied by the manufacturer at no cost to the operators. Based on 
these figures, the cost impact of the AD on U.S. operators is estimated 
to be $96,000, or $2,400 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the requirements of this AD 
action, and that no operator would accomplish those actions 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 adding the following new 
airworthiness directive:

96-25-13 JETSTREAM AIRCRAFT LIMITED: Amendment 39-9856. Docket 95-
NM-271-AD.

    Applicability: Model 4101 airplanes, constructors numbers 41004 
through 41047 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 (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 fatigue-related cracking in the rear pressure 
bulkhead, which could result in reduced structural integrity of the 
fuselage and, consequently, lead to the rapid decompression of the 
pressurized area of the airplane, accomplish the following:
    (a) Prior to the accumulation of 10,000 total landings, or 
within 6 months after the effective date of this AD, whichever 
occurs later, accomplish paragraphs (a)(1) and (a)(2) of this AD, in 
accordance with Jetstream Service Bulletin J41-53-020, Revision 1, 
dated June 4, 1996.
    (1) Perform a high frequency eddy current inspection to detect 
cracks of the boundary angle and joint angle of the rear pressure 
bulkhead, in accordance with the service bulletin. If any crack is 
detected, prior to further flight, repair it in accordance with a 
method approved by the Manager, Standardization Branch, ANM-113, 
FAA, Transport Airplane Directorate.
    (2) Modify the rear pressure bulkhead of the fuselage (Jetstream 
Modification JM41382A), in accordance with the service bulletin.
    (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.

    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.

    (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 inspection and modification shall be done in accordance 
with Jetstream Service Bulletin J41-53-020, Revision 1, dated June 
4, 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 January 31, 1997.

    Issued in Renton, Washington, on December 6, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-31605 Filed 12-26-96; 8:45 am]
BILLING CODE 4910-13-U