Discussion
On February 9, 2010, 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 Piper Aircraft, Inc. Models PA-32R-301T and PA-46-350P airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on February 19, 2010 (75 FR 7407). The NPRM proposed to require replacing specific spot-welded, V-band exhaust coupling with a riveted, V-band exhaust coupling.
Comments
We provided the public the opportunity to participate in developing this AD. We received one comment in support of the AD. The following presents the additional comments received on the proposal and FAA's response to each comment:
Comment Issue No. 1: Incorporate Additional Lycoming Service Instructions
Gerald Stroum and Gerald Blank suggest that Lycoming Service Instructions 1448 and 1238B be incorporated into the AD because they contain helpful instructions and procedures for the proper installation of exhaust components.
Mr. Stroum also suggests that adding a requirement to free all slip joints when replacing the clamp will assist in enabling the exhaust system to be installed and aligned correctly.
The commenters state that these types of clamps (spot welded) have been used with a long history of success in the automotive diesel industry, and the issue is more readily solved by proper installation than by a change in clamp design. Their experience shows proper installation, torque techniques, and pre-torque alignments of components go a long way in preventing clamp failures down the road.
We agree with the commenters that proper installation and maintenance, which includes freeing the slip joint to ensure proper operation, plays a key role in the longevity and proper function of the exhaust system.
The data in Lycoming Service Instruction 1448 contains references to part numbers that are not the subject of this AD; therefore, we have determined including reference to that service instruction would provide confusing and contradictory information. However, we agree Lycoming Service Instruction 1238B provides beneficial information about the proper assembly and torque procedures of V-band clamps.
We will change the final rule AD action to incorporate by reference Lycoming Service Instruction 1238B. We will not change the final rule AD action to incorporate reference to Lycoming Service Instruction 1448.
Comment Issue No. 2: Correct the Cost of Compliance
Gerald Blank, Ed Novak, and Shoreline Aviation, Inc. state that the Cost of Compliance section in the proposed AD incorrectly reflects the number of V-band clamps installed on the airplanes affected by this AD.
All three commenters suggest changing the Cost of Compliance section to accurately reflect the number of V-band clamps installed on each affected model airplane.
We agree with the commenters. After further research, we determined that Model PA 46 350P (Mirage) has two of the affected V-Band clamps installed, and Model PA 32R 301T (Saratoga II TC) has one. We will change the final rule AD action to incorporate this change.
Comment Issue No. 3: The AD Should Be Written Against the V-Band Clamp Instead of the Airplanes
Ed Novak and Shoreline Aviation, Inc. both suggest that since identical clamps have failed on other airplane models that prompted two previous ADs (AD 2000-11-04 for Commander Aircraft Company (Commander) Model 114TC airplanes and AD 2004-23-17 for Mooney Airplane Company, Inc., (Mooney) Model M20M airplanes), this AD should be written against the Lycoming engine/clamp combination restricting its use on any exhaust system.
Shoreline Aviation, Inc. states the incident that prompted this AD would not have happened if the previous ADs had been written against the clamp and not the airplanes.
Based on the specific reports the FAA has received to date regarding Piper Aircraft, Inc. Models PA-32R-301T and PA-46-350P airplanes and with the subsequent issuance of Piper Service Bulletin 1180A, the FAA initiated this AD action against certain Piper airplanes only.
We will continue to collect and analyze all available data to determine whether the condition exists in any other airplane configurations. We may take additional rulemaking action in the future to address either additional airplane configurations or the engine design depending on the FAA's determination of all existing and future information received.
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 incorporating reference to Lycoming Service Instruction 1238B and updating the Cost of Compliance section to accurately reflect how many V-band clamps each model of the airplanes affected by this AD has installed, and 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 the NPRM.
Costs of Compliance
We estimate that this AD affects 596 airplanes in the U.S. registry provided they have the affected V-band exhaust coupling installed.
We estimate the following costs to do the replacement for Model PA 32R-301T airplanes. These airplanes have one V-band clamp installed:
Labor Cost
Parts Cost
Total Cost Per Model PA-32R-301T Airplane
2 work-hours $85 per hour = $170
$714
$884
We estimate the following costs to do the replacement for Model PA 46 350P airplanes. These airplanes have two V-band clamps installed:
Labor Cost
Parts Cost
Total Cost Per Model PA-46-350P Airplane
2 work-hours per V-band clamp. 2 clamps per airplane: 4 work-hours $85 per hour = $340.
$714 per V-band clamp. $714 2 = $1,428.
$1,768
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-2010-0122; Directorate Identifier 2009-CE-067-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: