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-2005-21331; Directorate Identifier 2005-NE-07-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 DOT docket 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 ( printed page 58104) 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 Docket Management Facility Docket Offices 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 Docket Management Facility receives them.

Discussion

On October 16, 2003, ECi informed the FAA that an engine experienced an in-flight engine failure and uncommanded shutdown. The failure occurred after 50 hours time-in-service (TIS) after an engine overhaul. The engine overhaul included replacing the engine crankshaft, the connecting rods, and the connecting rod bearings. We conducted a post-accident investigation that included an engine teardown. The engine teardown showed that one connecting rod and one connecting rod bearing were destroyed. The three remaining connecting rod bearings had an unusual “tank tread” pattern around the surface that mates with the crankshaft journal. A visual examination of the three remaining connecting rods revealed the journal bores had the same “tank tread” pattern found on the mating surface of the bearings.

Results of the FAA's Investigation of New Connecting Rods

We approved reciprocating engine connecting rods, P/N AEL 11750, for use on Lycoming 360 and 540 series reciprocating engines under a Parts Manufacturer Approval (PMA). The Airmotive Engineering Corp, Division of Engine Components Incorporated, holds the PMA. ECi markets the parts as ECi parts. We determined the ECi engineering drawings for the connecting rods contain inadequate criteria to control circularity of the bearing bore. Because of that, the manufacturing process used to machine the bore resulted in excessive scalloping. The scalloping resulted in excessive variation in the circularity necessary for the proper functioning of the connecting rods. We also determined the inspection methods that ECi used to inspect the newly manufactured connecting rods were not sufficiently accurate to identify the manufacturing defects in circularity.

We obtained four new ECi connecting rods from the field and two new ECi connecting rods directly from ECi. A U.S. Government test facility measured the connecting rods using high-precision test measuring equipment. The test facility found the journal bores in all of the connecting rods had excessive scalloping. Our analysis of measurements from the test facility show that the scalloping prevents proper fitting between the connecting rod and it's associated rod bearing. The poor fit between these critical engine components results in a significant reduction in performance and fatigue strength. Journal bores with excessive surface scalloping or machine chattering can result in two adverse conditions:

(1) Poor contact between the journal bore and it's bearing substantially reduces heat transfer from the bearing. The resulting increase in bearing temperature substantially reduces the fatigue strength of the bearing.

(2) The scalloping or machine chattering prevents adequate development of the hydrodynamic oil film needed to lubricate and cool the bearing. This allows metal-to-metal contact between the bearing and the connecting rod journal

On December 22, 2003, ECi made a design drawing revision to better define dimensions and improve the quality control for the manufacture of the connecting rod, P/N AEL 11750. We have not received any reports of service difficulties for connecting rods, P/N AEL 11750, produced after January 2004 with the improved design.

This condition, if not corrected, could result in fatigue failure of the connecting rod and uncommanded shutdown of the engine.

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:

• Replacing certain serial-numbered ECi connecting rods, P/N AEL 11750, with 1,500 or more hours TIS on the connecting rod, within 50 hours TIS after the effective date of the AD.
• Replacing certain serial-numbered ECi connecting rods, P/N AEL 11750, with fewer than 1,500 hours TIS on the connecting rod, before accumulating 1,500 hours TIS on the connecting rod.

This proposed AD would also prohibit installing any ECi connecting rod, P/N AEL 11750, with a serial number 54/6 or lower, into any engine after the effective date of the AD.

Costs of Compliance

We estimate that this proposed AD would affect about 2,800 Lycoming Engines 360 and 540 series reciprocating engines installed on aircraft of U.S. registry. We also estimate that it would take about 4 work hours per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. Required parts would cost about $450 per connecting rod. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $1,988,000. ECi has indicated that they might provide operators and repair stations credit for returned connecting rods.

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 ( printed page 58105)

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: