SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES . Include “Docket No. FAA-2005-22358; Directorate Identifier 2005-NE-20-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the Docket Management System (DMS) Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78) or you may visit http://dms.dot.gov.

Examining the AD Docket

You may examine the docket that contains the proposal, any comments received and, any final disposition in person at the DMS Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES . Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

We received reports of about 30 failures of ECi cylinder assemblies, P/N AEL65102 series, with casting P/N AEL65099, installed on Lycoming Engines models 320, 360, and 540 series, parallel valve reciprocating engines. Parallel valve Lycoming reciprocating engines are identified by the intake and exhaust valves in a parallel configuration. We investigated the failures and discovered that cylinder head fatigue cracks start in the thin wall located between the counter-bore of the exhaust valve seat and adjacent cooling fin root. Our investigation concluded that the wall thickness of the affected area is too thin, making the wall vulnerable to fatigue cracking. Our investigation also concluded that the fatigue origin is not associated with surface damage resulting from cylinder head over-temperature conditions. Based on these findings, we issued Special Airworthiness Information Bulletin (SAIB) No. NE-01-32, dated July 18, 2001, to alert owners and operators to visually inspect, and to report and replace ECi cylinder heads if found cracked.

As a result of our investigation and issuing SAIB No. NE-01-32, ECi introduced an improved cylinder head design for casting P/N AEL65099, starting with serial number (SN) 9880. Their design change increased the cylinder head exhaust port wall thickness. Since the issuance of the SAIB, we continue to receive reports of cracking of ECi cylinder assemblies with casting P/N AEL65099, SNs 1 through 9879. The most recent report, from Kenya, described three cylinders showing cracks, with two of the cylinders separating from the barrel. This condition, if not corrected, could result in loss of engine power due to cracks in the cylinder assembly and possible engine failure caused by separation of a cylinder head. This proposed AD only applies to ECi “Classic Cast” cylinder assemblies identified with casting P/N AEL65099 and SNs 1 through 9879.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design.

We are proposing this AD, which would require the following:

• Determine if ECi cylinder assemblies, P/N AEL65102 series “Classic Cast”, with casting P/N AEL65099 and SN 1 through 9879 are installed on your engine; and
• If any cylinder assembly is an ECi P/N AEL65102 series “Classic Cast”, with casting P/N AEL65099 and a SN 1 through 9879, and has fewer than 800 operating hours-in-service (HIS) on the effective date of the proposed AD, replace the cylinder assembly at no later than 800 operating HIS. No action is required until the operating HIS reaches 800 hours.
• If any cylinder assembly is an ECi P/N AEL65102 series “Classic Cast”, with casting P/N AEL65099 and a SN 1 through 9879, and has 800 operating HIS or more on the effective date of the proposed AD, replace the cylinder assembly within 60 operating HIS after the effective date of the proposed AD.
• After the effective date of the proposed AD, do not install any ECi cylinder assembly, P/N AEL65102, with casting P/N AEL65099 that has a SN 1 through 9879, onto any engine.

Costs of Compliance

There were 9,879 ECi cylinder assemblies produced of the affected design available to the worldwide fleet. ECi reported that about fifteen percent of their cylinder assemblies go to foreign countries. We estimate ten percent of the remaining cylinders were never installed or are already removed from service, leaving 7,557 cylinder assemblies in service in the United States. We estimate that 1,574 Lycoming engines are in the United States with the subject cylinder assemblies installed. We estimate that it would take about two work hours per engine to perform the proposed aircraft inspections of the cylinder assemblies for applicability, and that the average labor rate is $65 per work hour. From the Lycoming Engines “Removal and Installation Labor Allowance Guidebook”, dated May 2000, the complete cylinder replacement for a four cylinder engine takes 12 hours, while the complete cylinder replacement for a six cylinder engine takes 16 hours. Required parts would cost about $1,000 per cylinder assembly. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $9,152,140. ECi indicated that they might give operators and repair stations credit for returned cylinder assemblies toward the purchase of new ECi cylinder assemblies. ( printed page 53588)

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 rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 the proposed regulation:

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. Would 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 regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

The Proposed Amendment

Under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows: