[Federal Register Volume 61, Number 238 (Tuesday, December 10, 1996)]
[Proposed Rules]
[Pages 65004-65006]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31268]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-CE-57-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).
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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 horizontal stabilizer upper and
lower skin, intercostal angles, and the horizontal stabilizer trailing
edge channel for cracks; and repairing any cracks or replacing any
cracked parts, as applicable. The proposed AD results from numerous
reports of cracking in these horizontal stabilizer areas on the
affected airplanes. The actions specified by the proposed AD are
intended to prevent structural failure of the horizontal stabilizer
caused by fatigue cracks, 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. 96-CE-57-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. 96-CE-57-AD.'' The
[[Page 65005]]
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. 96-CE-57-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 a number of incidents of fatigue
cracking in the areas of the horizontal stabilizer upper and lower
skin, intercostal angles, and the horizontal stabilizer trailing edge
channel. These conditions, if not detected and corrected, could lead to
structural failure of the horizontal stabilizer, which could result in
loss of control of the airplane.
Applicable Service Information
ASTA has issued Nomad Service Bulletin (SB) NMD-55-34, dated April
22, 1996, which includes procedures for inspecting the horizontal
stabilizer upper and lower skin, intercostal angles, and the horizontal
stabilizer trailing edge channel.
The CASA of Australia classified this service bulletin as mandatory
and issued FCAA AD/GAF-N22/72, dated August 1996, 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 horizontal
stabilizer upper and lower skin, intercostal angles, and the horizontal
stabilizer trailing edge channel for cracks; and repairing any cracks
or replacing any cracked parts, as applicable.
Accomplishment of the proposed inspections would be in accordance
with Nomad SB NMD-55-34, dated April 22, 1996. Accomplishment of any
proposed repair or replacement, as necessary and as applicable, would
be in accordance with the Nomad Structural Repair Manual, Chapter 55-
10-11.
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 2
workhours per airplane to accomplish the proposed initial inspections,
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 $1,800 or $120 per airplane. This figure
does not take into account the cost of repetitive inspections or the
cost to repair or replace any horizontal stabilizer upper and lower
skin, intercostal angles, or horizontal stabilizer trailing edge
channel. 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 horizontal stabilizer upper and lower skins,
intercostal angles, or horizontal stabilizer trailing edge channels
that may be found cracked during the inspections proposed by this
action.
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.
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. 96-CE-57-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 within the next 100 hours time-in-
service (TIS) after the effective date of this AD, unless already
accomplished, and thereafter at intervals not to exceed 100 hours
TIS.
To prevent structural failure of the horizontal stabilizer
caused by fatigue cracks, which could result in loss of control of
the airplane, accomplish the following:
(a) Inspect the horizontal stabilizer upper and lower skin,
intercostal angles, and the horizontal stabilizer trailing edge
channel for cracks in accordance with the ACCOMPLISHMENT
INSTRUCTIONS section of Nomad Service Bulletin (SB) NMD-55-34, dated
April 22, 1996.
[[Page 65006]]
(b) If any crack is found during any inspection required by this
AD, prior to further flight, repair or replace the cracked part or
area, as applicable, in accordance with the Nomad Structural Repair
Manual, Chapter 55-10-11. Those cracked areas that can be repaired
and those cracked areas that must be replaced are defined in Nomad
SB NMD-55-34, dated April 22, 1996, and the Nomad Structural Repair
Manual, Chapter 55-10-11.
(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. 96-31268 Filed 12-9-96; 8:45 am]
BILLING CODE 4910-13-U
