Discussion
On August 3, 2006, we issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to all Air Tractor, Inc. (Air Tractor) Model AT-602 airplanes. This proposal was published in the Federal Register as a supplemental notice of proposed rulemaking (NPRM) on August 9, 2006 (71 FR 45467). The supplemental NPRM proposed to require you to repetitively inspect (using the eddy current method) the wing center splice joint two outboard fastener holes on both of the wing main spar lower caps for fatigue cracking; repair or replace any wing main spar lower cap where fatigue cracking is found; and report any fatigue cracking found.
The following table contains AD actions that address the wing spar safe life of the Air Tractor airplane fleet:
Related Ad Actions
AD Number
Affected Air Tractor
Model Airplanes
Status
2000-14-51
AT-501, AT-502, and AT-502A
Superseded byAD 2001-10-04
2001-10-04
AT-400, AT-500, and AT-800 Series
Revised by AD 2001-10-04 R1
2001-10-04 R1
AT-400, AT-500, and AT-800 Series
Superseded by AD 2002-11-05
2002-11-05
AT-400, AT-401, AT-401B,
AT-402, AT-402A, AT-402B,
AT-501, AT-802, and AT-802A
Revised by AD 2002-11-05 R1
2002-13-02
AT-300, AT-301, AT-302, AT-400, and AT-400A Airplanes
Superseded by AD 2003-06-01
2002-11-03
AT-502, AT-502A, AT-502B, and AT-503A
Superseded by AD 2002-26-05
2002-26-05
AT-502, AT-502A, AT-502B, and AT-503A
Current
2003-06-01
AT-300, AT-301, AT-302, AT-400, and AT-400A
Current
2002-11-05 R1
AT-501
Current
2006-08-08
AT-400, AT-401, AT-401B, AT-402, AT-402A, and AT-402B
Current
2006-08-09
AT-802 and AT-802A
Current
You may view these ADs at the following Internet Web site addresses: http://www.airweb.faa.gov/Regulatory--and--Guidance--Library/rgAD.nsf/MainFrame?OpenFrameSet or http://www. gpoaccess.gov/fr/index.html.
Comments
We provided the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal and FAA's response to each comment:
Comment Issue No. 1: Publish the Manufacturer Service Information
Jack Buster with the Modification and Replacement Parts Association (MARPA) provides comments on how the FAA addresses publishing manufacturer service information as part of a proposed AD action. The commenter states that the proposed rule attempts to require compliance with a public law by reference to a private writing (as referenced in paragraph (e) of the proposed AD). The commenter would like the FAA to incorporate by reference (IBR) the Snow Engineering Company service information.
We agree with Mr. Buster. However, we do not IBR any document in a proposed AD action, instead we IBR the document in the final rule. Since we are issuing the proposal as a final rule AD action, the service information referenced in the NPRM is incorporated by reference.Comment Issue No. 2: Availability of IBR Documents in the Docket Management System (DMS)
Mr. Buster requests IBR documents be made available to the public by publication in the Federal Register or in the Docket Management System (DMS).
We are currently reviewing issues surrounding the posting of service bulletins in the Department of Transportation's DMS as part of the AD docket. Once we have thoroughly examined all aspects of this issue and have made a final determination, we will consider whether our current practice needs to be revised.
Conclusion
We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for minor editorial corrections. We have determined that these minor corrections:
Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in theNPRM.
Costs of Compliance
We estimate that this AD affects 107 airplanes in the U.S. registry.
We estimate the following costs to do the inspection:
Labor Cost
Parts Cost
Eddy Current Inspection
Total Cost Per Airplane
Total Cost on U.S. Operators
Initial inspection and installation of access panels 24 work-hours X $80 = $1,920
$645
* $500
$3,065
$327,955
Repetitive Inspection (each)
$60
* $800
$860
$92,020
* Eddy current inspections are an estimated flat cost that includes labor and use of equipment.
We estimate the following costs to do any necessary repairs that would be required based on the results of the proposed inspection. We have no way of determining the number of airplanes that may need this repair:
Labor Cost
Parts Cost
Total Cost Per Airplane
Install web plate, 8-bolt splice blocks, and cold work fastener holes: Air Tractor estimated a labor cost of $12,100. When broken down into work-hours, we estimated 151 work-hoursto complete the task. 151
work-hours X $80 = $12,080
$6,900
$18,980
Cold work fastener holes following Snow Engineering Co. Service Letter #244, dated April 25, 2005: 19 work-hours X $80 = $1,520
$1,350
$2,870
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.
We are 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 AD.
Regulatory Findings
We have determined that 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;
2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
3. 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.
We prepared a summary of the costs to comply with this AD (and other information as included in the Regulatory Evaluation) and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include ``Docket No. FAA-2004-20007; Directorate Identifier 2004-CE-50-AD'' in your request.
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 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. FAA amends Sec. 39.13 by adding a new AD to read as follows: