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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0715; Project Identifier AD-2020-00484-A;
Amendment 39-21190; AD 2020-16-06]
RIN 2120-AA64
Airworthiness Directives; Aviat Aircraft Inc.
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD)
for all
Aviat Aircraft Inc. Models A-1, A-1A, A-1B, A-1C-180, and A-1C-200
airplanes.
This AD requires repetitive inspections of the forward horizontal
stabilizer support assembly and the rear horizontal stabilizer support
tube and reporting information to the FAA. This AD was prompted by
field reports of complete failure of both the forward support assembly
and the rear support tube due to fatigue. The FAA is issuing this AD to
address the unsafe condition on these products.
DATES: This AD is effective September 1, 2020.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of September 1,
2020.
The FAA must receive comments on this AD by October 1, 2020.
ADDRESSES: You may send comments, using the procedures found in
14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov.
Follow the instructions for submitting comments.
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow
the
instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
For service information identified in this final rule, contact
Aviat Aircraft Inc., Al Humbert, 672 South Washington Street, Afton,
WY, 83110, United States; phone: (307) 885-3151; email:
dmir@aviataircraft.com; internet: https://aviataircraft.com. You may
view this service information at the FAA, Airworthiness Products
Section, Operational Safety Branch, 901 Locust, Kansas City, Missouri
64106. For information on the availability of this material at the FAA,
call (816) 329-4148. It is also available on the internet at https://www.
regulations.gov by searching for and locating Docket No. FAA-2020-0715.
Examining the AD Docket
You may examine the AD docket on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2020-
0715; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this final rule, any comments received, and other information. The
street address for the Docket Operations is listed above. Comments will
be available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Mark Dalrymple, Aerospace Engineer,
Denver ACO Branch, FAA, 26805 E. 68th Avenue, Denver, CO 80249; phone:
(303) 342-1090; email: mark.dalrymple@faa.gov.
SUPPLEMENTARY INFORMATION:
Discussion
The FAA received three field reports from Aviat Aircraft Inc. of
complete failure of the rear horizontal stabilizer inboard support
tube. The first incident, discovered during a scheduled inspection,
occurred in 2005, and the second incident, discovered while the
airplane was being re-skinned, occurred in 2009. The third incident was
discovered during a pre-flight inspection in 2012 and included a
complete failure of the forward horizontal stabilizer inboard support
assembly. Failure analysis of both parts from the 2012 incident
concluded they failed due to fatigue. In addition to these complete
failures of the rear support tube, the FAA received two field reports
from Aviat Aircraft Inc. of cracks in the rear support tube, discovered
during inspections, in 2005 and 2013. Aviat Aircraft Inc. subsequently
issued Service Bulletin No. 28, Revision A, dated April 2, 2015, which
requires a one-time inspection of the rear stabilizer inboard support
tube in response to the multiple reports of failures and cracks.
In addition to the 2012 incident, which involved a failure of both
supports, the FAA received two other field reports from Aviat Aircraft
Inc. of complete failure of the forward horizontal stabilizer inboard
support assembly, one in 2000 and one in 2019. In the first incident,
the failure occurred during ground handling after flight. In the second
incident the failure was discovered while the aircraft was being placed
in a hanger.
Failure of either the forward or rear support transfers loads to
the other support, increasing the likelihood that both could fail. This
condition, if not addressed, could result in stabilizer departure and
loss of airplane control.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Aviat Aircraft Inc. Service Bulletin No. 28,
Revision A, dated April 2, 2015 (Aviat SB No. 28, Revision A). This
service information contains procedures for inspecting and repairing
the rear stabilizer support tube. This service information is
reasonably available because the interested parties have access to it
through their normal course of business or by the means identified in
the ADDRESSES section.
FAA's Determination
The FAA is issuing this AD because it evaluated all the relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the same type design.
AD Requirements
This AD requires inspection for cracks and replacement if necessary
of the forward horizontal stabilizer support assembly. This AD also
requires inspecting the rear horizontal stabilizer support tube for
corrosion and damage and repair if necessary. This AD also requires
reporting the inspection results to the FAA.
FAA's Justification and Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies waiving notice and comment prior to adoption of this rule
because FAA risk assessment indicates there is an unacceptable short-
term risk of developing fatigue cracks through 25 percent of the cross
sectional area of the rear support tube on airplanes that have engaged
in tow operations. In addition, further FAA risk assessment indicates
there is an unacceptable short-term risk of developing fatigue cracks
through 25 percent of the cross sectional area of the forward support
assembly
on all airplanes. In the majority of known incidents at either location,
the support failed completely. Failure of either the forward or rear
support transfers loads to the other support, increasing the likelihood
that both could fail, which has occurred in one known incident. A
combined failure of both the forward and rear supports could result in
stabilizer departure and loss of airplane control. Therefore, the FAA
finds good cause that notice and opportunity for prior public comment
are impracticable. In addition, for the reasons stated above, the FAA
finds that good cause exists for making this amendment effective in
less than 30 days.
Comments Invited
This AD is a final rule that involves requirements affecting flight
safety and was not preceded by notice and an opportunity for public
comment. However, we invite you to send any written data, views, or
arguments about this final rule. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No.FAA-2020-0715;
Product Identifier AD-2020-00484-A'' at the beginning of your comments.
The FAA will consider all comments received by the closing date and may
amend this proposed AD because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
https://www.regulations.gov, including any personal information you
provide. The FAA will also post a report summarizing each substantive
verbal contact we receive about this final rule.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this AD contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this AD, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this AD. Submissions containing CBI should be sent to Mark
Dalrymple, Aerospace Engineer, Denver ACO Branch, FAA, 26805 E. 68th
Avenue, Denver, CO 80249. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.
The FAA will post all comments received, without change, to https://www.
regulations.gov, including any personal information you provide.
The FAA will also post a report summarizing each substantive verbal
contact we receive about this AD.
Differences Between This AD and the Service Information
The service information only applies to certain serial numbers of
the airplane models identified in this AD, while this AD applies to all
serial numbers of Aviat Aircraft Inc. Model A-1, A-1A, A-1B, A-1C-180,
and A-1C-200 airplanes. The service information only requires
inspecting the rear stabilizer support tube, while this AD requires
inspecting the forward stabilizer support assembly in addition to the
rear stabilizer support tube. The service information only requires a
one-time inspection, while this AD requires both initial and repetitive
inspections.
Costs of Compliance
The FAA estimates that this AD affects 941 airplanes of U.S.
registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
|
Action
|
Labor cost
|
Parts cost
|
Cost per
product
|
Cost on
U.S. operators
|
| Inspect forward horizontal stabilizer
inboard support assembly
for cracks. |
1 work-hour x $85.00 per hour
= $85.00 |
$25.00
|
$110.00
|
$103,510.00
|
| Inspect rear horizontal stabilizer
inboard support tube weld joints
for corrosion and
damage. |
0.5 work-hour x $85.00 per hour
= $42.50 |
0.00
|
42.50
|
39,992.50
|
The FAA estimates the following costs
to do any necessary repairs
or replacements that would be required based on the results of the
inspection. The FAA has no way of determining the number of airplanes
that might need these replacements:
On-Condition Costs
|
Action
|
Labor cost
|
Parts cost
|
Cost per
product
|
| Replace forward horizontal stabilizer
support tube. |
2 work-hours x $85.00 per hour
= $170.00 |
$296.00
|
$466.00
|
| Repair rear horizontal stabilizer
support tube weld joints
and install new support tube insert. |
4.5 work-hours x $85.00 per hour
= $382.50 |
163.00
|
545.50
|
| Report if cracks are found. |
0.5 work-hour x $85.00 per hour
= $42.50 |
0.00
|
42.50
|
Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to be
approximately .5 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, completing and reviewing the collection of
information. All responses to this collection of information are mandatory.
Send
comments regarding this burden estimate or any other aspect of this
collection of information, including suggestions for reducing this
burden to: Information Collection Clearance Officer, Federal Aviation
Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs
describes in more detail the scope of the Agency's authority.
The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.
Regulatory Flexibility Act
The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because FAA has determined
that it has good cause to adopt this rule without notice and comment,
RFA analysis is not required.
Regulatory Findings
This AD will not have federalism implications under Executive Order
13132. This AD will not have a substantial direct effect 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.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866, and
(2) Will not affect intrastate aviation in Alaska.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):
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