Airworthiness Directives; Teledyne Continental Motors (Formerly Bendix) S-20, S-1200, D-2000, and D-3000 Series Magnetos

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for Teledyne Continental Motors (TCM) (formerly Bendix) S-20, S-1200, D-2000, and D-3000 series magnetos equipped with impulse couplings. That AD currently requires replacing riveted-impulse coupling assemblies, which are worn beyond limits, with serviceable riveted-impulse couplings or snap-ring impulse couplings. This proposed AD would require a reduced inspection interval for magnetos with riveted-impulse couplings installed on certain Lycoming engine models. The proposed AD would not lower the inspection interval for magnetos with snap-ring impulse couplings. This proposed AD would also limit the Applicability to certain Lycoming engine models. This proposed AD results from data provided by the manufacturer that shows a need to reduce the inspection intervals for riveted-impulse couplings used on certain Lycoming engine models. We are proposing this AD to prevent failure of the magneto impulse coupling and possible engine failure.

DATES:

We must receive any comments on this proposed AD by February 22, 2005.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD:

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 93-ANE-07-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: (781) 238-7055.
• By e-mail: 9-ane-adcomment@faa.gov

You can get the service information identified in this proposed AD from Teledyne Continental Motors, P.O. Box 90, Mobile, AL 36601; telephone (334) 438-3411.

You may examine the AD docket, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Jerry Robinette, Senior Aerospace Engineer, Propulsion, Atlanta Certification Office, FAA, Small Airplane Directorate, 1 Crown Center, 1895 Phoenix Blvd., Suite 450, Atlanta, GA, 30349; telephone (770) 703-6096, fax (770) 703-6097.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to provide any written relevant data, views, or arguments on this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 93-ANE-07-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will date-stamp your postcard and mail it back to you. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. If a person contacts us verbally, and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

Examining the AD Docket

You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.

Discussion

On May 29, 1996, the FAA issued AD 96-12-07, Amendment 39-9649 (61 FR 29934, June 13, 1996). That AD requires:

• An initial inspection of riveted and snap-ring impulse couplings before accumulating 500 hours time-since-new or overhauled (TSN) or time-since-last inspection (TSLI) on impulse couplings that have fewer than 450 hours TSN or TSLI on the effective date of that AD.
• An initial inspection of riveted and snap-ring impulse couplings before accumulating 50 hours time-in-service (TIS) after the effective date of that AD on impulse couplings that have 450 or more hours TSN or TSLI on the effective date of that AD.
• Repetitive inspections within 500 hours TSLI.
• Replacing impulse couplings that fail the inspection.

That AD was the result of redesigning the impulse coupling assembly to include snap-ring fastening technology, which strengthens the cam axle and reduces wear and reports of impulse couplings with the snap-ring design that were worn beyond limits. That condition, if not corrected, could result in failure of the magneto impulse coupling and possible engine failure.

Actions Since AD 96-12-07 Was Issued

Since we issued that AD, the manufacturer has added procedures and requirements for inspecting impulse couplings that have snap rings to the applicable Service Support Documents.

Relevant Service Information

We have reviewed and approved the technical contents of TCM Mandatory Service Bulletin (MSB) MSB645, dated April 4, 1994, that describes procedures for:

• Inspecting the impulse coupling assemblies for wear and, if necessary, replacing the riveted assembly with a snap-ring impulse coupling, and
• Marking the magneto data plate with a letter “A” after installing a snap-ring impulse coupling.

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. Therefore, we are proposing this AD, which would require:

• An initial visual inspection of riveted-impulse couplings that have 100 or more hours TSN or TSLI on the effective date of the proposed AD, within 10 hours TIS after the effective date of this AD, or
• An initial visual inspection of riveted-impulse couplings that have fewer than 100 hours TSN or TSLI on the effective date of the proposed AD, before accumulating 100 hours TSN or TSLI, and
• Repetitive inspections of riveted-impulse couplings within intervals of 100 hours TSLI.
• An initial visual inspection of snap-ring impulse couplings that have 450 or more hours TSN or TSLI on the effective date of the proposed AD, within 50 hours TIS after the effective date of the AD, or
• An initial visual inspection of snap-ring impulse couplings that have fewer than 450 hours TSN or TSLI before accumulating 500 hours TSN or TSLI, and
• Repetitive inspections of snap-ring impulse couplings within intervals of 500 hours TSLI.
• Replacing impulse couplings that fail the inspection.

The proposed AD would require that you do these actions using the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect about 4,200 magnetos installed on airplanes of U.S. registry. We also estimate that it would take about 1 work hour per magneto to perform the proposed actions, and that the average labor rate is $65 per work hour. The reduced inspection interval would require doing the inspections about four times more often. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $1,092,000.

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 summary of the costs to comply with this proposal and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 93-ANE-07-AD” in your request.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.