AD 2008-19-05

This AD becomes effective October 20, 2008.

You can get the service information identified in this AD from Engine Components, Inc., 9503 Middlex, San Antonio, TX 78217; Phone (800) 324-2359; fax (210) 820-8102; http://www.eci2fly.com.

The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

Peter W. Hakala, Aerospace Engineer, Special Certification Office, FAA, Rotorcraft Directorate, 2601 Meacham Blvd., Fort Worth, TX 76193; e-mail: peter.w.hakala@faa.gov; telephone (817) 222-5145; fax (817) 222-5785.

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to Lycoming Engines (formerly Textron Lycoming) models 320, 360, and 540 series, “Parallel Valve” reciprocating engines, with certain Engine Components Inc. (ECi) cylinder assemblies, part number (P/N) AEL65102 series “Titan”, installed. We published the proposed AD in the Federal Register on May 19, 2008 (73 FR 28756). That action proposed to require initial and repetitive visual inspections and compression tests to detect cracks at the head-to-barrel interface, replacement of cylinder assemblies found cracked, and replacement of certain cylinder assemblies, at new reduced times-in-service.

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

One commenter, the Aircraft Owners and Pilots Association, states that the 50-hour inspection interval should be increased to 100 hours, to reduce the economic impact of the cylinder assembly inspections. Another commenter, a private citizen, states that the cost of the 50-hour inspections was not considered in the NPRM economic estimate.

We do not agree. We selected the 50-hour inspection interval so that aluminum cylinder cracks could be detected before a head separation occurred. By removing leaking cylinder heads discovered during the periodic 50-hour inspections, the probability of having an in flight head separation is greatly reduced. Also, the 50-hour inspection interval coincides with the scheduled maintenance for normal engine oil and filter changes. Also, the costs of compliance in the NPRM did include costs for the additional cylinder assembly inspections. We did not change the AD.

One commenter, a private citizen, states that it is too expensive to retire all the subject cylinder assemblies at the normal overhaul time. Another commenter, a private citizen, states that it is unreasonable for general aviation airplane owners, in Part 91 use, to be required to retire cylinder assemblies at the time-between-overhaul or at normal engine overhaul time.

We do not agree. The subject cylinder assemblies can be safely run to the normal TBO with the required 50-hour inspections, with compression tests. Because of metallurgical analysis results of the fatigue cracks in the aluminum alloy cylinder heads, and also the history of the head separation hours-in-service, the probability of a head separation is greater with the subject cylinder assemblies running past the time-between-overhaul time. Therefore, we do not consider the cylinder assemblies to be airworthy past the normal engine overhaul time. We did not change the AD.

One commenter, ECi., states that the cylinder assembly serial number range in the proposed AD for the Group “B” cylinders is slightly different from the serial numbers listed in the ECi Mandatory service Bulletin No. 08-1. The commenter states that several additional cylinder serial numbers should be included in Group “B”.

We do not agree. We researched the cylinder assembly serial numbers in the proposed AD and they are correct. The Group “A” cylinder assemblies go up to serial number 35171-22. The Group “B” cylinder assemblies start at serial number 35239-01. We discussed the serial number comment with ECi. They agree that the serial number range in the proposed AD is correct. ECi states that they have revised the serial numbers in ECi. Mandatory Service Bulletin (MSB) No. 08-1 to match the serial numbers in the AD, and issued MSB No. 08-1, Revision 3, dated August 19, 2008. We now reference this MSB Revision 3 in the AD.

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD as proposed. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

We estimate that this AD will affect 13,000 ECi cylinder assemblies installed in aircraft of U.S. registry. The visual inspection and compression tests will take about 4 work-hours for each engine. An individual cylinder replacement will require $1,100 for parts and 6 work-hours. Lycoming engines with a set of 4 ECi cylinders will require 12 work-hours for the cylinder replacement. Lycoming engines with a set of 6 ECi cylinders will require 16 work-hours for the cylinder replacement. We estimate 18 percent of the affected population of cylinders will be replaced. We estimate the total cost of the AD to U.S. operators to be $7,952,000. Our estimate is exclusive of any possible warranty coverage.

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 rulemaking action.

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 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 placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by adding the following new airworthiness directive: