[Federal Register Volume 61, Number 229 (Tuesday, November 26, 1996)]
[Rules and Regulations]
[Pages 60015-60016]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-29863]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-CE-49-AD; Amendment 39-9833; AD 96-24-08]
RIN 2120-AA64
Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-
300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-
502 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
applies to certain Air Tractor, Inc. (Air Tractor) Models AT-250, AT-
300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-
502 airplanes that are equipped with a Gerdes part number (P/N) A-850-5
or Cleveland P/N 60-9 parking brake valve. This action requires
replacing the parking brake valve with a Scott P/N 4500A-2 parking
brake valve. This AD results from several reports of the parking brake
valve inadvertently slipping to the ``PARK'' position during flight,
which causes constant pressure on the brakes. When the pilot applies
the brake upon landing, this pressure causes the airplane to overturn.
The actions specified by this AD are intended to prevent the airplane
from overturning because of extreme pressure applied to the brake if
the parking brake valve inadvertently slips to the ``PARK'' position
during flight.
DATES: Effective December 23, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of December 23, 1996.
Comments for inclusion in the Rules Docket must be received on or
before February 14, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket 96-CE-49-AD, Room 1558, 601 E. 12th
Street, Kansas City, Missouri 64106.
Service information that applies to this AD may be obtained from
Air Tractor Inc., P. O. Box 485, Olney, Texas 76374; telephone (817)
564-5616; facsimile (817) 564-2348. This information may also be
examined at the Federal Aviation Administration (FAA), Central Region,
Office of the Assistant Chief Counsel, Attention: Rules Docket 96-CE-
49-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. Werner Koch, Aerospace Engineer,
FAA, Aircraft Certification Office, 2601 Meacham Boulevard, Fort Worth,
Texas 76193-0150; telephone (817) 222-5133; facsimile (817) 222-5960.
SUPPLEMENTARY INFORMATION:
Events Leading to This AD
The FAA has received several reports of the parking brake valve
inadvertently slipping to the ``PARK'' position during flight on Air
Tractor Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401,
AT-402, AT-501, and AT-502 airplanes. When the parking brake is in the
``PARK'' position, a constant pressure is applied to the brakes, which
cannot be relieved or reduced when the pilot removes pressure from the
brake pedals. This pressure builds to the point that when the pilot
applies the brake upon landing to slow the airplane, the airplane
overturns.
The airplanes in the incidents described above were equipped with
Gerdes part number (P/N) A-850-5 or Cleveland P/N 60-9 parking brake
valves. The FAA has determined that these Gerdes or Cleveland parking
brake valves should be replaced with Scott parking brake valves, P/N
4500A-2, on certain Air Tractor Models AT-250, AT-300, AT-301, AT-302,
AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 airplanes.
Applicable Service Information
Air Tractor has issued Snow Engineering Co. Service Letter #76,
dated December 12, 1988, which specifies replacing Gerdes part number
A-850-5 and Cleveland P/N 60-9 parking brake valves with Scott parking
brake valves, P/N 4500A-2. Air Tractor Service Letter #76 Instructions
specify procedures for accomplishing this parking brake valve
replacement.
The FAA's Determination
After examining the circumstances and reviewing all available
information related to the incidents described above, including the
referenced service information, the FAA has determined that AD action
should be taken to prevent the airplane from overturning because of
extreme pressure applied to the brake if the parking brake valve
inadvertently slips to the ``PARK'' position during flight.
Explanation of the Provisions of This AD
Since an unsafe condition has been identified that is likely to
exist or develop in other Air Tractor Models AT-250, AT-300, AT-301,
AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 airplanes
of the same type design that are equipped with a Gerdes (P/N) A-850-5
or Cleveland P/N 60-9 parking brake valve, the FAA is implementing AD
action. This AD requires replacing these Gerdes or Cleveland parking
brake valves with a Scott P/N 4500A-2 parking brake valve.
Accomplishment of this replacement is in accordance with Air Tractor
Service Letter #76 Instructions, as referenced in Snow Engineering Co.
Service Letter #76, dated December 12, 1988.
Since a situation exists (possibility of the airplane overturning
during landing) that requires the immediate adoption of this
regulation, it is found that notice and opportunity for public prior
comment hereon are impracticable, and that good cause exists for making
this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting immediate flight safety and, thus, was not
preceded by notice and opportunity to comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 will be considered,
and this rule may be amended in light of the comments received. Factual
information that supports the commenter's ideas and suggestions is
extremely helpful in evaluating the effectiveness of the AD action and
determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the rule. All comments
[[Page 60016]]
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 AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket No. 96-CE-49-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and is not a significant regulatory action under
Executive Order 12866. It has been determined further that this action
involves an emergency regulation under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979). If it is determined that
this emergency regulation otherwise would be significant under DOT
Regulatory Policies and Procedures, a final regulatory evaluation will
be prepared and placed in the Rules Docket (otherwise, an evaluation is
not required). A copy of it, if filed, may be obtained from the Rules
Docket.
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:
96-24-08 Air Tractor, Inc.: Amendment 39-9833; Docket No. 96-CE-49-
AD.
Applicability: The following airplane models and serial numbers,
certificated in any category, that are equipped with a Gerdes part
number (P/N) A-850-5 or Cleveland P/N 60-9 parking brake valve :
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Model Serial Numbers
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AT-250.............................. 250-0491.
AT-300.............................. 300-0001 through 300-0708.
AT-301.............................. 301-0001 through 301-0708.
AT-302.............................. 302-0001 through 302-0708.
AT-400.............................. 400-0001 through 400-0708.
AT-400A............................. 400A-0001 through 400A-0708.
AT-401.............................. 401-0001 through 401-0708.
AT-402.............................. 402-0001 through 402-0708.
AT-501.............................. 501-0001 through 501-0036.
AT-502.............................. 502-0001 through 502-0036.
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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 (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 within the next 75 hours time-in-
service after the effective date of this AD, unless already
accomplished.
To prevent the airplane from overturning because of extreme
pressure applied to the brake if the parking brake valve
inadvertently slips to the ``PARK'' position during flight,
accomplish the following:
(a) Replace the Gerdes P/N A-850-5 or Cleveland P/N 60-9 parking
brake valve with a Scott P/N 4500A-2 parking brake valve. Accomplish
this replacement in accordance with Air Tractor Service Letter #76
Instructions, as referenced in Snow Engineering Co. Service Letter
#76, dated December 12, 1988.
(b) 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.
(c) 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, Aircraft Certification Office, 2601
Meacham Boulevard, Fort Worth, Texas 76193-0150. The request shall
be forwarded through an appropriate FAA Maintenance Inspector, who
may add comments and then send it to the Manager, Fort Worth ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Fort Worth ACO.
(d) The replacement required by this AD shall be done in
accordance with Air Tractor Service Letter #76 Instructions, as
referenced in Snow Engineering Co. Service Letter #76, dated
December 12, 1988. 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 Air Tractor
Inc., P. O. Box 485, Olney, Texas 76374. 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.
(e) This amendment (39-9833) becomes effective on December 23,
1996.
Issued in Kansas City, Missouri, on November 15, 1996.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 96-29863 Filed 11-25-96; 8:45 am]
BILLING CODE 4910-13-U
