[Federal Register Volume 62, Number 23 (Tuesday, February 4, 1997)]
[Rules and Regulations]
[Pages 5145-5147]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-2609]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-86-AD; Amendment 39-9914; AD 97-03-08]
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

[[Page 5146]]

4101 airplanes, that requires repetitive inspections to detect cracking 
of the offset lightening hole on the drag brace of the left and right 
main landing gear (MLG); and replacement of these braces with braces 
having a centralized lightening hole. This replacement terminates the 
repetitive inspections This amendment is prompted by a report 
indicating that fatigue cracking was detected on the upper link of a 
drag brace. The actions specified by this AD are intended to prevent 
fatigue cracking of the drag braces of the MLG, which, if not 
corrected, could cause the MLG to fail and, consequently, result in 
reduced controllability of the airplane during takeoff, landing, and 
taxiing.

DATES: Effective March 11, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 11, 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 in the Federal Register on November 12, 1996 
(61 FR 58016). That action proposed to require repetitive detailed 
visual inspections of the offset lightening hole on the drag brace of 
the left and right MLG to detect cracking. That action also proposed to 
require, prior to further flight, the replacement of any cracked brace 
with a brace having a centralized lightening hole. Such replacement 
would constitute terminating action for the repetitive detailed visual 
inspections.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Conclusion

    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 1 Jetstream Model 4101 airplane of U.S. 
registry will be affected by this AD.
    It will take approximately 1 work hour per airplane to accomplish 
the required inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the required inspection on 
the single U.S. operator is estimated to be $60 per inspection cycle.
    It will take approximately 2 work hours per airplane to accomplish 
the required replacement, at an average labor rate of $60 per work 
hour. Required parts will be provided by the manufacturer at no cost to 
the operator. Based on these figures, the cost impact of the required 
replacement on the single U.S. operator is estimated to be $120.
    The cost impact figures discussed above are 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:

97-03-08  Jetstream Aircraft Limited: Amendment 39-9914. Docket 96-
NM-86-AD.

    Applicability: Model 4101 airplanes having constructors numbers 
41004 through 41009 inclusive, and 41017; equipped with a main 
landing gear (MLG) on which drag braces having Jetstream part 
numbers (P/N) AIR84352-0 through AIR84352-4, inclusive, and having 
offset lightening holes, are installed; certificated in any 
category.

    Note 1: Drag braces having Jetstream part numbers (P/N) 
AIR84352-0 through AIR84352-4 inclusive, can have either offset or 
centralized lightening holes. This AD applies only to those 
airplanes equipped with those drag braces that have the offset 
lightening holes.
    Note 2: 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 (c) 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 cracking of the drag brace of the left and 
right MLG which, if not corrected, could cause the MLG to fail and, 
consequently, lead reduced controllability of the airplane during 
takeoff, landing, and taxiing, accomplish the following:
    (a) Within 50 hours time-in-service after the effective date of 
this AD, perform a detailed visual inspection to detect cracking at 
the offset lightening hole on the drag brace of the left and right 
MLG, in accordance with

[[Page 5147]]

Part 1 of Jetstream Service Bulletin J41-32-049, Revision 1, dated 
January 15, 1996.

    Note 3: Accomplishment of the visual inspection in accordance 
with Part 1 of Jetstream Service Bulletin J41-32-049, dated November 
21, 1995, is considered acceptable for compliance with this 
paragraph.

    (1) If no cracking is detected, repeat this inspection 
thereafter at intervals not to exceed 50 hours time-in-service until 
the requirements of paragraph (b) of this AD have been accomplished.
    (2) If any cracking is detected, prior to further flight, 
replace the drag brace with a drag brace that has Jetstream part 
number (P/N) AIR84352-4 and a centralized lightening hole, in 
accordance with Part 2 of Jetstream Service Bulletin J41-32-049, 
Revision 1, dated January 15, 1996. This replacement constitutes 
terminating action for the repetitive inspections and replacement of 
that brace required by paragraphs (a) and (b), respectively, of this 
AD.

    Note 4: Accomplishment of the replacement in accordance with 
Part 2 of Jetstream Service Bulletin J41-32-049, dated November 21, 
1995, is considered acceptable for compliance with paragraphs (a)(2) 
and (b) of this AD.

    (b) Within two years after the effective date of this AD, 
replace any MLG drag brace that has P/N AIR84352-0 through AIR84352-
4, inclusive, and an offset lightening hole, with a drag brace that 
has Jetstream P/N AIR84352-4 and a centralized lightening hole, in 
accordance with Part 2 of Jetstream Service Bulletin J41-32-049, 
Revision 1, dated January 15, 1996. This replacement constitutes 
terminating action for the repetitive inspections required by 
paragraph (a) of this AD.
    (c) 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 5: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (d) 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.
    (e) The inspections and replacments shall be done in accordance 
with Jetstream Service Bulletin J41-32-049, Revision 1, dated 
January 15, 1996, which contains the following list of effective 
pages:

------------------------------------------------------------------------
                                  Revision level                        
            Page No.              shown on page     Date shown on page  
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1, 3...........................  1..............  Jan. 15, 1996.        
2, 4-9.........................  Original.......  Nov. 21, 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 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.
    (f) This amendment becomes effective on March 11, 1997.

    Issued in Renton, Washington, on January 28, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-2609 Filed 2-3-97; 8:45 am]
BILLING CODE 4910-13-U