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-2006-24785; Directorate Identifier 2006-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 DOT Web site, anyone can find and read the comments in any of our dockets. This includes 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 DOT 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 ( printed page 30079) 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

We determined that 23 failures of similar crankshafts in Lycoming 360 and 540 series reciprocating engines have occurred due to subsurface material flaws that progress to a fatigue failure. Lycoming Engines issued Mandatory Service Bulletin (MSB) No. 552, MSB No. 553, MSB No. 566, Supplement No. 1 to MSB No. 566, MSB No. 569, and MSB No. 569A to address the crankshaft failures. We issued AD 2002-19-03 (MSB No. 552 and MSB No. 553 crankshaft populations), AD 2005-19-11 (MSB No. 566 crankshaft population), and AD 2006-06-16 (Supplement No. 1 to MSB No. 566 crankshaft population) to also address the crankshaft failures. The group of crankshafts listed in Lycoming MSB No. 569, dated February 21, 2006, and in the revised version, Lycoming MSB No. 569A, dated April 11, 2006, which is referenced in this proposed AD, has been found to have the same material flaws as those crankshafts addressed by the earlier MSBs and ADs noted. We have determined that the crankshafts listed in Lycoming MSB No. 569 and MSB No. 569A, must be replaced because of the similarity in the design and manufacture with the groups that have previously failed. This condition, if not corrected, will result in total engine power loss, in-flight engine failure, and possible loss of the aircraft.

Relevant Service Information

We reviewed and approved the technical contents of Lycoming MSB No. 569A, dated April 11, 2006. That MSB describes procedures for replacing crankshafts listed by serial number (SN) in that MSB.

Lycoming records indicate the engine SNs in MSB No. 569A, Tables 1, 2, 3, and 4, may have a suspect crankshaft installed. MSB No. 569A Table 5 lists the crankshaft SNs that Lycoming confirmed were part of the suspect population. Because the engine and crankshaft populations are so large, they are not repeated in this proposed AD. Owner operators must determine applicability by comparing engine and crankshaft SNs listed in MSB No. 569A.

We have also reviewed and approved the technical contents of Lycoming Service Instruction No. 1009AR, dated June 22, 2004, that specifies engine time between overhaul periods.

Differences Between the Proposed AD and the Manufacturer's Service Information

Lycoming MSB No. 569A, dated April 11, 2006, requires compliance at the next accessibility of the crankshaft, but no later than February 21, 2009. However, this proposed AD would require compliance at the next accessibility of the crankshaft, but no later than the next engine overhaul specified in Lycoming Service Instruction (SI) No. 1009AR, dated June 22, 2004. SI No. 1009AR requires engine overhaul at the specified hourly interval, but no later than 12 years since new, or since the previous engine overhaul. The AD compliance interval could be longer than the MSB No. 569 and MSB No. 569A intervals if the affected engine does not require maintenance that allows accessibility of the crankshaft, or if the engine accumulates hours at a low rate per calendar year. We are allowing this later compliance termination date because we determined that the unsafe condition is unrelated to calendar time and that crankshaft removal at overhaul will reduce the risk of failure to an acceptable level.

Lycoming IO-390 and AEIO-390 engines listed in MSB No. 569A are experimental engines not affected by this AD. Lycoming Engines included these engine models in MSB No. 569A because a suspect crankshaft may have been installed.

FAA's Determination and Requirements of the Proposed AD

We 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 crankshafts at the next engine overhaul as specified in Lycoming Service Instruction No. 1009AR, dated June 22, 2004, or at the next separation of the crankcase, whichever is earlier. The proposed AD would require you to use the service information described previously to perform these actions.

Costs of Compliance

We estimate that this proposed AD would affect 3,774 engines installed on airplanes of U.S. registry. Because the proposed AD compliance interval coincides with engine overhaul or other engine maintenance, we estimate no additional labor hours will be needed to comply with this proposed AD. Parts would cost about $16,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to be $60,384,000. Lycoming said it may provide the parts for $2,000, until February 21, 2009, but will not extend the parts price beyond that date.

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: