SUPPLEMENTARY INFORMATION:

The FAA proposed to amend 14 CFR part 39 with a proposed airworthiness directive (AD). The proposed AD applies to Lycoming Engines (formerly Textron Lycoming) AEIO-360, IO-360, O-360, LIO-360, LO-360, AEIO-540, IO-540, O-540, and TIO-540 series reciprocating engines rated at 300 horsepower (HP) or lower. We published the proposed AD in the Federal Register on July 22, 2005 (70 FR 42282). That action proposed to require replacing certain crankshafts within 50 hours time-in-service or 6 months after the effective date of the proposed AD, whichever is earlier.

Examining the AD Docket

You may examine the docket that contains the AD, 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 DMS receives them.

Comments

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

Will Additional Engines and Crankshafts Be Affected in the Future

One commenter asks if additional serial numbered engines and crankshafts will be affected in the future.

At this time we do not anticipate that the affected population will increase, but Lycoming and the FAA are monitoring crankshaft performance.

Affected Engines and Crankshafts

The same commenter asks why these engines and crankshafts are the only ones affected by the SB and AD.

Both the previous AD (2002-19-03) and this AD advise that the affected population of engines and crankshafts were manufactured in a specific time period. We are addressing that time period.

Suspect Crankshafts Should Be Either Tested or Replaced

One commenter states that suspect crankshafts should be either tested or replaced before further flight, because the problem with these crankshafts is similar to the problem that caused the crankshaft failures on the 540 engines.

We disagree. The compliance interval in this AD is based on an assessment of operating stresses, service experience, and duty cycle of the affected engine population. The compliance interval differs from that imposed in AD 2002-19-03 due to differences in these parameters.

Request To Include Lycoming TIO-540-AE2A and Other Unspecified Engine Models

One commenter requests that we include the Lycoming TIO-540-AE2A and other unspecified engine models in this AD. The commenter states that many of the TIO-540-AE2A engines have never been recalled or replaced yet should be, because recent litigation has shown that Lycoming's crankshaft end core sample test is insufficient.

We disagree. We have seen no evidence that refutes the validity of the test. Further, AD 2002-19-03 (the previous AD) effective on September 20, 2002, described two groups of crankshafts. We required one crankshaft group to be removed before further flight, and we required the other crankshaft group to have a sample of the crankshaft material tested. The crankshafts in each group were selected based on our evaluation of the risk both groups presented. Crankshafts from either group may be installed in the TIO-540-AE2A engine model. No failures of crankshafts listed in either group have occurred since.

Conclusion

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.

Costs of Compliance

We estimate that this AD will affect 1,128 engines installed on aircraft of U.S. registry. We estimate that it will take the following work hours to perform the inspection:

We also estimate that it will take about 33 work hours to replace the crankshaft. We estimate the average labor rate is $65 per work hour and that required parts for each engine will cost about $16,218. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $18,594,724. Lycoming Engines informed us that they intend to supply the new parts at no charge, which may substantially reduce the estimated cost of this AD.

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 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; ( printed page 54620)

(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 .

Adoption of the Amendment

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:

Authority: 49 U.S.C. 106(g), 40113, 44701.

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

2005-19-11 Lycoming Engines: Amendment 39-14276. Docket No. FAA-2005-21864; Directorate Identifier 2005-NE-29-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective October 21, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Lycoming Engines (Formerly Textron Lycoming) AEIO-360, IO-360, O-360, LIO-360, LO-360, AEIO-540, IO-540, O-540, and TIO-540 series reciprocating engines, rated at 300 horsepower (HP) or lower, manufactured new, rebuilt, overhauled after March 1, 1999, or that had a crankshaft installed after March 1, 1999. These engines are installed on, but not limited to, the following aircraft:

Unsafe Condition

(d) This AD results from 12 crankshaft failures in Lycoming model 360 and 540 series engines rated at 300 HP or lower. We are issuing this AD to prevent failure of the crankshaft, which could result in total engine power loss, in-flight engine failure, and possible loss of the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within 50 hours time-in-service or 6 months after the effective date of this AD, whichever is earlier, unless the actions have already been done.

Engines Manufactured Before March 1, 1999

(f) If Lycoming Engines manufactured new, rebuilt, or overhauled your engine before March 1, 1999, and you haven't had the crankshaft replaced, no further action is required.

AEIO-540, IO-540, O-540, and TIO-540 Series Engines Manufactured New or Rebuilt, Overhauled, or That Had a Crankshaft Installed After March 1, 1999

(g) For AEIO-540, IO-540, O-540, and TIO-540 series engines manufactured new or rebuilt, overhauled, or that had a crankshaft installed after March 1, 1999, do the following:

(1) If Table 1 or Table 2 of Lycoming Mandatory Service Bulletin (MSB) No. 566, dated July 11, 2005, lists your engine serial ( printed page 54622) number (SN), use Table 4 to verify the crankshaft SN.

(2) If Table 4 of Lycoming MSB No. 566, dated July 11, 2005, lists your crankshaft SN, replace the crankshaft with a crankshaft that is not listed in Table 4 of Lycoming MSB No. 566, dated July 11, 2005.

AEIO-360, IO-360, O-360, LIO-360, and LO-360 Series Engines Manufactured New or Rebuilt, Overhauled, or That Had a Crankshaft Installed After March 1, 1999

(h) For AEIO-360, IO-360, O-360, LIO-360, and LO-360 series engines manufactured new or rebuilt, overhauled, or that had a crankshaft installed after March 1, 1999, do the following:

(1) If Table 3 of Lycoming MSB No. 566, dated July 11, 2005, lists your engine SN, use Table 4 to verify the crankshaft SN.

(2) If Table 4 of Lycoming MSB No. 566, dated July 11, 2005, lists your crankshaft SN, replace the crankshaft with a crankshaft that is not listed in Table 4 of Lycoming MSB No. 566, dated July 11, 2005.

Prohibition Against Installing Certain Crankshafts

(i) After the effective date of this AD, do not install any crankshaft that has a SN listed in Table 4 of Lycoming MSB No. 566, dated July 11, 2005, into any engine.

Alternative Methods of Compliance (AMOCs)

(j) The Manager, New York Aircraft Certification Office, has the authority to approve AMOCs for this AD if requested using the procedures found in 14 CFR 39.19.

Related Information

(k) None.

Material Incorporated by Reference

(l) You must use Lycoming Mandatory Service Bulletin No. 566, dated July 11, 2005, to perform the actions required by this AD. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Lycoming, 652 Oliver Street, Williamsport, PA 17701; telephone (570) 323-6181; fax (570) 327-7101, or on the Internet at http://www.Lycoming.Textron.com for a copy of this service information. You may review copies at the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001, on the Internet at http://dms.dot.gov, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.