AD 96-23-19

[Federal Register Volume 61, Number 225 (Wednesday, November 20, 1996)]
[Rules and Regulations]
[Pages 58985-58987]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-29492]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-CE-55-AD; Amendment 39-9823; AD 96-23-19]
RIN 2120-AA64


Airworthiness Directives; Air Tractor, Inc. AT-300, AT-400, and 
AT-500 Series 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-300, AT-
400, and AT-500 series airplanes. This AD requires installing both a 
new flap actuator overtravel stop and a roll pin through the overtravel 
stop and jack screw. This AD results from incidents where the flap 
actuator overtravel stop nut disengaged from the jack screw. The flap 
pushrod pressed against the aileron pushrod, which caused difficulty in 
moving the ailerons. The actions specified by this AD are intended to 
prevent interference between the flap pushrod and the aileron pushrod 
caused by the flap actuator overtravel nut disengaging, which could 
result in loss of aileron control.

DATES: Effective December 18, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 18, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before February 7, 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-55-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. 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-55-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:
Bob May, Aerospace Engineer, FAA, Aircraft Certification Office, 2601 
Meacham Boulevard, Fort Worth, Texas 76193-0150; telephone (817) 222-
5156; facsimile (817) 222-5960.

SUPPLEMENTARY INFORMATION:

Events Leading to the Issuance of This AD

    The FAA has received reports involving Air Tractor Models AT-402 
and AT-502 airplanes, where the flap actuator overtravel stop nut 
disengaged from the jack screw. The flap pushrod pressed against the 
aileron pushrod, which caused difficulty in moving the ailerons. Snow 
Engineering Co. (the parent company of Air Tractor) and the FAA have 
simulated this condition on factory airplanes through a laboratory 
environment, which resulted in the same difficulty in moving the 
ailerons.
    This condition, if not detected and corrected, could result in loss 
of aileron control on certain Air Tractor Models AT-300, AT-301, AT-
302, AT-400, AT-400A, AT-401, AT-401A, AT-401B, AT-402, AT-402A, AT-
402B, AT-501, AT-502, AT-502A, AT-502B, and AT-503A airplanes.

Applicable Service Information

    Snow Engineering Co. has issued Service Letter (SL) #140, dated 
November 27, 1995, Revised October 10, 1996, which applies to certain 
Air Tractor AT-300, AT-400, and AT-500 series airplanes. This SL 
specifies procedures for installing both a new flap actuator overtravel 
stop nut and a roll pin through the overtravel stop and jack screw.

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 interference between the flap

[[Page 58986]]

pushrod and the aileron pushrod caused by the flap actuator overtravel 
nut disengaging, which could result in loss of aileron control.

Explanation of the Provision of This AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Air Tractor AT-300, AT-400, and AT-500 series 
airplanes of the same type design, this AD requires installing both a 
new flap actuator overtravel stop and a roll pin through the overtravel 
stop and jack screw. Accomplishment of these installations is required 
in accordance with Snow Engineering Co. SL #140, dated November 27, 
1995, Revised October 10, 1996.
    Since a situation exists (possible loss of aileron control) 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 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-55-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:

96-23-19  Air Tractor Inc: Amendment 39-9823; Docket No. 96-CE-55-
AD.

    Applicability. The following airplane models and serial numbers, 
certificated in any category:
    Models AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-401A, 
AT-401B, AT-402, AT-402A, and AT-402B, airplanes, serial numbers 
300-0001 through 401B-1013;
    Models AT-501, AT-502, AT-502A, AT-502B, AT-503A airplanes, 
serial numbers 502-0001 through 502B-0398;

    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 action to 
address it. Compliance: Required within the next 25 hours time-in-
service after the effective date of this AD, unless already 
accomplished.

    To prevent interference between flap pushrod and the aileron 
pushrod caused by the flap actuator overtravel nut disengaging, 
which could result in loss of aileron control, accomplish the 
following:
    (a) Install both a new flap actuator overtravel stop and a roll 
pin through the overtravel stop and jack screw in accordance with 
the REWORK INSTRUCTIONS section of Snow Engineering Co. Service 
Letter #140, dated November 27, 1995, Revised October 10, 1996.
    (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, Airplane Certification Office (ACO), 
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 installations required by this AD shall be accomplished 
in accordance with Snow Engineering Co. Service Letter #140, dated 
November 27, 1995, Revised October 10, 1996. 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 my 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 (39-9823) becomes effective on December 18, 
1996.


[[Page 58987]]


    Issued in Kansas City, Missouri, on November 12, 1996.
Henry A. Armstrong,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-29492 Filed 11-19-96; 8:45 am]
BILLING CODE 4910-13-M