Airworthiness Directives; Jetstream Model 4101 Airplanes

[Federal Register Volume 61, Number 126 (Friday, June 28, 1996)]
[Rules and Regulations]
[Pages 33646-33647]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-15956]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-159-AD; Amendment 39-9678; AD 96-13-10]
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 airplanes, that requires 
modification of the existing diaphragms on the surround structure of 
the Type II emergency exit. This amendment is prompted by a report 
indicating that, during fatigue tests on a Model 4101 test article, 
fatigue-related cracking was found in the surround structure of a Type 
II emergency exit. The actions specified by this AD are intended to 
prevent such cracking in the surround structure, which could result in 
reduced structural integrity of the fuselage pressure vessel.

DATES: Effective August 2, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 2, 1996.

ADDRESSES: The service information referenced in this AD may be 
obtained from A.I.R. American Support, Inc., 13850 McLaren Road, 
Herndon, Virginia 22071. 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) 
227-2141; 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 in the Federal Register on January 19, 1996 (61 
FR 1300). That action proposed to require modification of the existing 
diaphragms on the surround structure of the Type II emergency exit.
    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 Proposal

    One commenter supports the proposal.

Request to Revise Applicability of Proposal

    One commenter requests that the applicability of the proposed rule 
be revised to eliminate airplanes on which the modification of the 
surround structure was accomplished during production.
    The FAA concurs. Since issuance of the notice, Jetstream has issued 
Revision 1 of Service Bulletin J41-53-014, dated February 9, 1996. In 
its technical content, this revision is essentially identical to the 
original issue (which was referenced in the notice as the appropriate 
source for service information). However, the effectivity listing of 
Revision 1 specifies only those airplanes on which the modification was 
not accomplished during production. Those airplanes have serial numbers 
41004 through 41044, inclusive; the modification was installed during 
production on airplanes beginning with serial number 41045.
    Accordingly, the FAA has revised the final rule to make it 
applicable only to airplanes having serial numbers 41004 through 41044, 
inclusive. Additionally, the FAA has revised the final rule to 
reference Revision 1 of the Jetstream service bulletin as an additional 
source of service information.

[[Page 33647]]

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 with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 41 Jetstream Model 4101 airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 19 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 35 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 $39,900, or $2,100 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. However, the FAA has been advised 
that at least 5 airplanes of U.S. registry already have been modified; 
therefore, the future cost impact of this AD is reduced by at least 
$10,500.

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:

96-13-10  Jetstream Aircraft Limited: Amendment 39-9678. Docket 95-
NM-159-AD.

    Applicability: Model 4101 airplanes; having serial numbers 41004 
through 41044, 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 use the authority 
provided in paragraph (b) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    -To prevent fatigue-related cracking in the surround structure 
of the Type II emergency exit, which could result in reduced 
structural integrity of the fuselage pressure vessel, accomplish the 
following:
    -(a) Prior to the accumulation of 7,200 total landings, or 
within 1,400 landings after the effective date of this AD, whichever 
occurs later, modify the existing diaphragms on the surround 
structure of the Type II emergency exit in accordance with Jetstream 
Service Bulletin J41-53-014, dated July 24, 1995; or Revision 1, 
dated February 9, 1996.
    -(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 modification shall be done in accordance with Jetstream 
Service Bulletin J41-53-014, dated July 24, 1995; or Jetstream 
Service Bulletin J41-53-014, Revision 1, dated February 9, 1996, 
which contains the following list of effective pages:

------------------------------------------------------------------------
                                  Revision level                        
            Page No.              shown on page-    Date shown on page  
------------------------------------------------------------------------
1, 3-..........................  1-.............  Feb. 9, 1996.         
2, 4-13-.......................  Original-......  July 24, 1995.        
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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 A.I.R. American Support, Inc., 13850 
McLaren Road, Herndon, Virginia 22071. 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 2, 1996.

    Issued in Renton, Washington, on June 17, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-15956 Filed 6-27-96; 8:45 am]
BILLING CODE 4910-13-P

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