[Federal Register Volume 61, Number 238 (Tuesday, December 10, 1996)]
[Proposed Rules]
[Pages 65002-65004]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31267]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-CE-98-AD]
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: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: This document proposes to adopt a new airworthiness directive
(AD) that would apply to Aerospace Technologies of Australia Pty Ltd.
(ASTA) Models N22B, N22S, and N24A airplanes. The proposed action would
require repetitively inspecting the stub wing upper front spar cap
flanges for cracks, and repairing any cracked part. The proposed 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 the proposed AD are intended to prevent structural failure
of
[[Page 65003]]
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: Comments must be received on or before February 21, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 95-CE-98-AD, Room 1558, 601 E.
12th Street, Kansas City, Missouri 64106. Comments may be inspected at
this location between 8 a.m. and 4 p.m., Monday through Friday,
holidays excepted.
Service information that applies to the proposed AD may be obtained
from Aerospace Technologies of Australia Pty Ltd., ASTA DEFENCE,
Private Bag No. 4, Beach Road Lara 3212, Victoria, Australia. This
information also may be examined at the Rules Docket at the address
above.
FOR FURTHER INFORMATION CONTACT: Mr. Ron Atmur, Aerospace Engineer,
FAA, Los Angeles Aircraft Certification Office, 3960 Paramount
Boulevard., Lakewood, California 90712; telephone (310) 627-5224;
facsimile (310) 627-5210.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed 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 proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket No. 95-CE-98-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Central Region, Office of the Assistant Chief Counsel,
Attention: Rules Docket No. 95-CE-98-AD, Room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106.
Discussion
The Civil Aviation Safety Authority (CASA), which is the
airworthiness authority for Australia, recently notified the FAA that
an unsafe condition may exist on certain ASTA Models N22B, N22S, and
N24A airplanes. The CASA reports that fatigue tests show that the stub
wing upper front spar cap flanges could fail over time because of
fatigue. These conditions, if not detected and corrected, could lead to
structural failure of the front spar and subsequent loss of control of
the airplane.
Applicable Service Information
Nomad Service Bulletin (SB) NMD-53-6, dated October 21, 1986,
includes procedures for inspecting (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.
The CASA of Australia classified this service bulletin as mandatory
and issued FCAA AD/GAF-N22/52, dated January 1987, in order to assure
the continued airworthiness of these airplanes in Australia.
The FAA's Determination
This airplane model is manufactured in Australia and is type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, the CASA of Australia has kept the
FAA informed of the situation described above. The FAA has examined the
findings of the CASA of Australia; reviewed all available information,
including the service information referenced above; and determined that
AD action is necessary for products of this type design that are
certificated for operation in the United States.
Explanation of the Provisions of the Proposed AD
Since an unsafe condition has been identified that is likely to
exist or develop in other ASTA Models N22B, N22S, and N24A airplanes of
the same type design that are registered in the United States, the
proposed AD would require repetitively inspecting the stub wing upper
front spar cap flanges for cracks, and repairing any cracked part.
Accomplishment of the proposed inspections would be in accordance with
Nomad SB NMD-53-6, dated October 21, 1986. Accomplishment of any
proposed repair, if necessary, would be in accordance with a scheme
obtained from the FAA, Los Angeles Aircraft Certification Office.
Cost Impact
The FAA estimates that 15 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 6
workhours per airplane to accomplish the proposed initial inspection,
and that the average labor rate is approximately $60 an hour. Based on
these figures, the total cost impact of the proposed 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 would 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 proposed herein would 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
proposal would 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) if promulgated,
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 draft regulatory evaluation
prepared for this action has been placed in the Rules Docket. A copy of
it may be obtained by contacting the Rules Docket at the location
provided under the caption ADDRESSES.
[[Page 65004]]
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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:
Aerospace Technologies of Australia Pty Ltd.: Docket No. 95-CE-98-
AD.
Applicability: Models N22B, N22S, and N24A airplanes (all serial
numbers), 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 (d) 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 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, unless already
accomplished, and thereafter at intervals not to exceed 2,650 hours
TIS.
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, accomplish the following:
(a) 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.
(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, California 90712. 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) All persons affected by this directive may obtain copies of
the document referred to herein upon request to Aerospace
Technologies of Australia Pty Ltd., ASTA DEFENCE, Private Bag No. 4,
Beach Road Lara 3212, Victoria, Australia; or may examine this
document at the FAA, Central Region, Office of the Assistant Chief
Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
Issued in Kansas City, Missouri, on December 2, 1996.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 96-31267 Filed 12-9-96; 8:45 am]
BILLING CODE 4910-13-U