[Federal Register Volume 60, Number 193 (Thursday, October 5, 1995)]
[Proposed Rules]
[Pages 52130-52131]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-24712]



 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 60, No. 193 / Thursday, October 5, 1995 / 
Proposed Rules  

[[Page 52130]]


DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-CE-59-AD]


Airworthiness Directives; Air Tractor, Incorporated Models AT-802 
and AT-802A 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 Air Tractor, Incorporated (Air Tractor) Models 
AT-802 and AT-802A airplanes. The proposed action would require 
repetitively replacing the main landing gear legs. Failure of the main 
landing gear legs on an AT-802A in the field prompted the proposed 
action. The actions specified by the proposed AD are intended to 
prevent possible failure of the main landing gear legs, which, if not 
detected and corrected, could result in loss of control of the landing 
operations of the airplane.

DATES: Comments must be received on or before December 5, 1995.

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-59-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 Air Tractor Incorporated, P. O. Box 485, Olney, Texas 76374; 
telephone (817) 564-5616; facsimile (817) 564-2348. This information 
also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Bob May, Aerospace Engineer, FAA, 
Aircraft Certification Office, 2601 Meacham Boulevard, Fort Worth, 
Texas 76193-0150; telephone (817) 222-5155; facsimile (817) 222-5960.

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-59-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-59-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The FAA received a report of the collapse of an Air Tractor AT-802A 
airplane equipped with 1.56-inch thick main landing gear legs, part 
number (P/N) 40091-2. The investigation revealed that the parked AT-
802A airplane's main landing gear failed after having made 
approximately 3,500 landings. There was slight rust under the clamp 
block where the failure started. This failure of the main landing gear 
legs in the field has prompted a re-evaluation of the fatigue life of 
the legs presented in the life limited parts section of the Airplane 
Maintenance Manual, Airworthiness Limitations Section, defined by 
section 23.159 of the Federal Aviation Regulations (14 CFR 23.159). The 
1.56-inch thick landing gear legs were heat treated to a higher 
ultimate tensile stress. This higher than normal heat treatment has 
made them more brittle than gears used on other Air Tractor models.
    Air Tractor has issued Service Bulletin (SB) 104A, dated July 29, 
1995, which specifies procedures for replacing the main landing gear 
legs on Models AT-802 and AT 802A airplanes.
    After examining the circumstances and reviewing all available 
information related to the incidents described above, the FAA has 
determined that AD action should be taken to prevent possible failure 
of the main landing gear legs, which, if not detected and corrected, 
could result in loss of control of the landing operations and possible 
loss of the airplane.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Air Tractor Models AT-802 and AT-802A 
airplanes of the same type design, the proposed AD would require 
replacing the main landing gear legs every 3,000 landings.
    The FAA estimates that 18 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 12 hours 
per airplane to accomplish the proposed action, and that the average 
labor rate is approximately $60 an hour. Parts cost approximately 
$2,816 per airplane. Based on these figures, the total cost impact of 
the proposed AD on U.S. operators is estimated to be $63,648 ($3,536 
per airplane). This figure is based on the assumption that no affected 
airplane owner/operator has replaced the main landing gear legs and 
does not take into account the number of repetitive replacements each 
operator would incur over the life of the airplane. The FAA has no way 
of determining how many main landing gear replacements each owner/
operator will incur.
    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship 

[[Page 52131]]
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 USC 106(g), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
(AD) to read as follows:

Air Tractor Incorporated: Docket No. 95-CE-59-AD.

    Applicability: Model AT-802 and AT-802A 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 (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 upon the accumulation of 3,000 
landings or within the next 25 landings after the effective date of 
this AD, whichever occurs later, unless already accomplished, and 
thereafter at intervals not to exceed 3,000 landings.

    Note 2: If the number of landings is not known, calculate by 
multiplying three landings per one hour time-in service.

    To prevent possible failure of the main landing gear legs, 
which, if not detected and corrected, could result in loss of 
control of landing operations and possible loss of the airplane, 
accomplish the following:

    (a) Replace the main landing gear legs, Air Tractor part number 
40091-2, in accordance with Air Tractor Service Bulletin (SB) 104A, 
dated July 29, 1995.

    (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 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, Fort Worth Aircraft 
Certification Office, 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 
Aircraft Certification Office.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Fort Worth Aircraft Certification Office.

    (d) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to Air Tractor 
Incorporated, P. O. Box 485, Olney, Texas 76374; telephone (817) 
564-5616; facsimile (817) 564-2348 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 September 28, 1995.

John R. Colomy,

Acting Manager, Small Aircraft Directorate, Aircraft Certification 
Service.

[FR Doc. 95-24712 Filed 10-4-95; 8:45 am]

BILLING CODE 4910-13-U