Discussion
What Events Have Caused This AD?
A review of FAA's service difficulty report (SDR) database shows several incidents of cracks and corrosion in the flap control torque tube on Piper PA-23 series airplanes. One incident of a broken flap control torque tube resulted in a split flap condition during approach.
What Is the Potential Impact if FAA Took No Action?
Cracked or corroded flap torque tubes, if not detected and corrected, could result in damage to the flap control torque tube and failure of the flap operating system. If such failure occurred during landing or takeoff, then a split flap condition could occur with potential loss of control of the airplane.
Has FAA Taken Any Action to This Point?
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 certain Piper Models PA-23, PA-23-160, PA-23-235, PA-23-250, and PA- E23-250 airplanes that do not incorporate a certain design flap control torque tube or torque tube assembly. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on January 27, 2003. The NPRM proposed to require you to repetitively inspect the flap control torque tube for cracks, corrosion, wear, or elongation of the attachment bolt holes; and would require you to replace any damaged flap control torque tube with either an improved design flap control torque tube or flap control torque tube assembly. The repetitive inspections would no longer be necessary when the improved design flap control torque tube or flap control torque tube assembly is installed.
Was the Public Invited To Comment?
The FAA encouraged interested persons to participate in the making of this amendment. We did not receive any comments on the proposed rule or on our determination of the cost to the public.
FAA's Determination
What Is FAA's Final Determination on This Issue?
After careful review of all available information related to the subject presented above, we have determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. We have determined that these minor corrections:
--Provide 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 the NPRM.
How Does the Revision to 14 CFR Part 39 Affect This AD?
On July 10, 2002, FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relates to special flight permits, alternative methods of compliance, and altered products. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.
Cost Impact
How Many Airplanes Does This AD Impact?
We estimate that this AD affects 3,733 airplanes in the U.S. registry.
What Is the Cost Impact of This AD on Owners/Operators of the Affected Airplanes?
We estimate the following costs to accomplish the inspection:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
8 workhours x $60 per hour =
$480.
None for inspection
$480 per airplane
$1,791,840.
We estimate the following costs to accomplish any necessary replacement that will be required based on the results of the inspection. We have no way of determing the number of airplanes that may need such repair/replacement:
Labor cost
Parts cost
Total cost per airplane
4 workhours x $60 per hour = $240
$452 per airplane
$692 per airplane.
Regulatory Impact
Does This AD Impact Various Entities?
The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.
Does This AD Involve a Significant Rule or Regulatory Action?
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) 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 final evaluation prepared for this action is contained 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, 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.
39.13 [Amended]
2. FAA amends 39.13 by adding a new AD to read as follows: