AD 97-11-12

[Federal Register Volume 62, Number 103 (Thursday, May 29, 1997)]
[Rules and Regulations]
[Pages 28997-28999]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-14077]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-CE-98-AD; Amendment 39-10041; AD 97-11-12]
RIN 2120-AA64


Airworthiness Directives; Aerospace Technologies of Australia Pty 
Ltd. (Formerly Government Aircraft Factory) Models N22B, N22S, and N24A 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to Aerospace Technologies of Australia Pty Ltd. (ASTA) Models 
N22B, N22S, and N24A airplanes. This action requires repetitively 
inspecting the stub wing upper front spar cap flanges for cracks, and 
repairing any cracked part. This AD results from fatigue tests that 
show that the stub wing upper front spar cap flanges could fail over 
time because of fatigue. The actions specified by this AD are intended 
to prevent structural failure of the front spar caused by cracks in the 
stub wing upper front spar cap flanges, which could result in loss of 
control of the airplane.

DATES: Effective July 11, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 11, 1997.

ADDRESSES: Service information that applies to this AD may be obtained 
from Aerospace Technologies of Australia Pty Ltd., ASTA DEFENCE, 
Private Bag No.

[[Page 28998]]

4, Beach Road Lara 3212, Victoria, Australia. This information may also 
be examined at the Federal Aviation Administration (FAA), Central 
Region, Office of the Assistant Chief Counsel, Attention: Rules Docket 
95-CE-98-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 
64106; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. Ron Atmur, Aerospace Engineer, 
FAA, Los Angeles Aircraft Certification Office, 3960 Paramount 
Boulevard, Lakewood, California 90712; telephone (562) 627-5224; 
facsimile (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Events Leading to the Issuance of This AD

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to include an AD that would apply to ASTA Models N22B, 
N22S, and N24A airplanes was published in the Federal Register as a 
notice of proposed rulemaking (NPRM) on December 10, 1996 (61 FR 
65002). The NPRM proposed to require repetitively inspecting the stub 
wing upper front spar cap flanges for cracks, and repairing any cracked 
part. Accomplishment of the proposed inspections as specified in the 
NPRM would be in accordance with Nomad Service Bulletin NMD-53-6, dated 
October 21, 1986. Accomplishment of any proposed repair (if necessary) 
as specified in the NPRM would be in accordance with a scheme obtained 
from the FAA, Los Angeles Aircraft Certification Office.
    The NPRM resulted from fatigue tests that show that the stub wing 
upper front spar cap flanges could fail over time because of fatigue.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposed AD or the FAA's determination of the cost to the public.

The FAA's Determination

    After careful review of all available information related to the 
subject presented above, the FAA has determined that air safety and the 
public interest require the adoption of the rule as proposed except for 
minor editorial corrections. The FAA has determined that these minor 
corrections will not change the meaning of the AD and will not add any 
additional burden upon the public than was already proposed.

Cost Impact

    The FAA estimates that 15 airplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 6 workhours per 
airplane to accomplish the required action, and that the average labor 
rate is approximately $60 an hour. Based on these figures, the total 
cost impact of the AD on U.S. operators is estimated to be $5,400 or 
$360 per airplane. This figure does not take into account the cost of 
repetitive inspections or the cost to repair any cracked stub wing 
upper front spar cap flanges. The FAA has no way of determining the 
number of repetitive inspections each operator will incur over the life 
of each affected airplane or the number of stub wing upper front spar 
cap flanges that may be found cracked and need to be repaired.

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 copy of the final evaluation prepared for this 
action is contained in the Rules Docket. A copy of it may be obtained 
by contacting 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 a new airworthiness directive 
(AD) to read as follows:

97-11-12  Aerospace Technologies of Australia PTY LTD: Amendment 39-
10041; Docket No. 95-CE-98-AD.

    Applicability: Models N22B, N22S, and N24A airplanes (all serial 
numbers), certified 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, alternation, 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 in the body of this AD, unless 
already accomplished.
    To prevent structural failure of the front spar caused by cracks 
in the stub wing upper front spar cap flanges, which would result in 
loss of control of the airplane, accomplish the following:
    (a) Prior to accumulating 1,700 hours time-in-service (TIS) or 
within the next 300 hours TIS after the effective date of this AD, 
whichever occurs later, and thereafter at intervals not to exceed 
2,650 hours TIS, inspect, using both visual and eddy current 
methods, the stub wing front spar cap flanges in the area of Buttock 
Line (BL) 47.6 for fatigue cracks in accordance with the 
ACCOMPLISHMENT INSTRUCTIONS section of Nomad Service Bulletin NMD-
53-6, dated October 21, 1986.
    (b) If any crack is found during any inspection required by this 
AD, prior to further flight, obtain a repair scheme from the 
manufacturer through the Los Angeles Aircraft Certification Office 
(ACO) at the address specified in paragraph (d) of this AD, and 
incorporate this repair scheme. This repair does not eliminate the 
repetitive inspection requirement of this AD.
    (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) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, FAA, Los Angeles ACO, 3960 Paramount 
Boulevard, Lakewood,

[[Page 28999]]

California 90172. The request shall be forwarded through an 
appropriate FAA Maintenance Inspector, who may add comments and then 
send it to the Manager, Los Angeles ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (e) The inspections required by this AD shall be done in 
accordance with Nomad Service Bulletin NMD-53-6, dated October 21, 
1986. 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 Aerospace Technologies of 
Australia Pty Ltd., ASTA DEFENCE, Private Bag No. 4, Beach Road Lara 
3212, Victoria, Australia. Copies may be inspected at the FAA, 
Central Region, Office of the Assistant Chief Counsel, Room 1558, 
601 E. 12th Street, Kansas City, Missouri, or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (f) This amendment (39-10041) becomes effective on July 11, 
1997.

    Issued in Kansas City, Missouri, on May 22, 1997.
Henry A. Armstrong,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-14077 Filed 5-28-97; 8:45 am]
BILLING CODE 4910-13-U