03-6998. Airworthiness Directives; Textron Lycoming, Direct-Drive Reciprocating Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The Federal Aviation Administration (FAA) proposes to supersede an existing airworthiness directive (AD), applicable to Textron Lycoming, direct-drive reciprocating engines (except O-145, O-320H, O-360E, LO-360E, LTO-360E, O-435, and TIO-541 series engines). That AD currently requires inspection of the crankshaft gear installation and rework or replacement of the gears where necessary after a propeller strike, sudden stoppage, at overhaul, or whenever gear train repair is required. This proposal would revise the definitions for sudden stoppage and propeller strike. This proposal is prompted by a change to the definition of a propeller strike or sudden stoppage. The actions specified in the proposed AD are intended to prevent loosening or failure of the crankshaft gear retaining bolt, which may cause sudden engine failure.

DATES:

Comments must be received by May 27, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 89-ANE-10-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via the Internet must contain the docket number in the subject line. Comments may be inspected at this location between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from Textron Lycoming, 652 Oliver Street, Williamsport, PA 17701, U.S.A. This information may be examined at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Norm Perenson, Aerospace Engineer, New York Aircraft Certification Office, FAA, Engine and Propeller Directorate, 10 Fifth Street, 3rd floor, Valley Stream, NY 11581-1200; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 89-ANE-10-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRM's

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 89-ANE-10-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

On July 12, 1991, the FAA issued AD 91-14-22, Amendment 39-6916 (56 FR 33205, July 19, 1991), to require inspection of the crankshaft gear installation and rework or replacement of the gears where necessary during overhaul, after a propeller strike, sudden stoppage, or whenever gear train repair is required. That action was prompted by reports of loosening and disengagement of the gear retaining bolt which could result in loss of the main camshaft drive train and critical engine accessories. That condition, if not corrected, could result in loosening or failure of the crankshaft gear retaining bolt, which may cause sudden engine failure.

Since AD 91-14-22 was issued, Textron Lycoming has issued mandatory Service Bulletin (SB) No. 475C, dated January 30, 2003, and the definition of a propeller strike has been expanded to include:

• Any incident, whether or not the engine is operating, that requires repair to the propeller beyond minor dressing of the blades.
• A sudden drop in engine revolutions per minute (RPM) while impacting water, tall grass, or similar yielding medium where propeller damage is not normally incurred.

Textron Lycoming has also included instructions in the maintenance manuals for inspections at overhaul and whenever repair of the gear train is required.

Manufacturer's Service Information

The FAA has reviewed and approved the technical contents of Textron Lycoming Mandatory Service Bulletin (MSB) No. 475C, dated January 30, 2003, that describes procedures for inspection and repair of the crankshaft and gear assembly.

FAA's Determination of an Unsafe Condition and Proposed Actions

Since an unsafe condition has been identified that is likely to exist or develop on other Textron Lycoming direct-drive reciprocating engines of this same type design, the proposed AD would supersede AD 91-14-22 to revise the definitions of a propeller strike and sudden engine stoppage. The actions must be done in accordance with the service information described previously.

Economic Analysis

There are approximately 175,000 Textron Lycoming, direct-drive reciprocating engines of the affected design in the worldwide fleet. The FAA estimates that 125,000 engines installed on aircraft of U.S. registry would be affected by this proposed AD. The FAA also estimates that it would take approximately 7 work hours per engine to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $420 per engine. Based on these figures, the total cost of the proposed AD to U.S. operators is estimated to be $52,500,000.

Regulatory Analysis

This proposed rule does not have federalism implications, as defined in Executive Order 13132, because it 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this proposed rule.

For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39—AIRWORTHINESS DIRECTIVES

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

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

§ 39.13

[Amended]

2. Section 39.13 is amended by removing Amendment 39-6916 (56 FR 33205, July 19, 1991), and by adding a new airworthiness directive, to read as follows:

Textron Lycoming: Docket No. 89-ANE-10-AD. Supersedes AD 91-14-22, Amendment 39-6916.

Applicability: This airworthiness directive (AD) is applicable to all Textron Lycoming direct-drive reciprocating engines except O-145, O-320H, O-360E, LO-360E, LTO-360E, TO-360E, O-435, and TIO-541 series engines.

Note 1:

This AD applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Compliance with this AD is required as indicated before further flight if the engine has experienced a propeller strike as defined in paragraph (b) of this AD, unless already done.

To prevent loosening or failure of the crankshaft gear retaining bolt, which may cause sudden engine failure, do the following:

(a) Inspect, and if necessary repair, the crankshaft counterbored recess, the alignment dowel, the retaining bolt and lock plate, the bolt hole threads, and the crankshaft gear for wear, galling, corrosion, and fretting in accordance with steps 1 through 7 of Textron Lycoming Mandatory Service Bulletin No. 475C, dated January 30, 2003.

Definition of Propeller Strike

(b) For the purposes of this AD, a propeller strike is defined as follows:

(1) Any incident, whether or not the engine is operating, that requires repair to the propeller other than minor dressing of the blades.

(2) Any incident during engine operation in which the propeller impacts a solid object that causes a drop in revolutions per minute (RPM) and also requires structural repair of the propeller (incidents requiring only paint touch-up are not included). This is not restricted to propeller strikes against the ground.

(3) A sudden RPM drop while impacting water, tall grass, or similar yielding medium, where propeller damage is not normally incurred.

(c) The preceding definitions include situations where an aircraft is stationary and the landing gear collapses causing one or more blades to be substantially bent, or where a hanger door (or other object) strikes the propeller blade. These cases should be handled as sudden stoppages because of potentially severe side loading on the crankshaft flange, front bearing, and seal.

Alternative Methods of Compliance

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, New York Aircraft Certification Office (NYACO). Operators must submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, NYACO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the NYACO.

Special Flight Permits

(e) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be done.

Issued in Burlington, Massachusetts, on March 17, 2003.

Robert G. Mann,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.