96-12-07 Teledyne Continental Motors: Amendment 39-9649.  Docket 93-ANE-07. Supersedes AD 78-09-07 R3, Amendment 39- 4538.

Applicability: Teledyne Continental Motors (TCM)  (formerly Bendix) S-20, S-1200, D-2000, and D-3000 series  magnetos equipped with impulse couplings, installed on but  not limited to reciprocating engine powered aircraft  manufactured by Beech, Cessna, Mooney, and Piper.

NOTE 1: This airworthiness directive (AD) applies to each  magneto 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 magnetos that have been modified, altered, or repaired  so that the performance of the requirements of this AD is  affected, the owner/operator must use the authority provided  in paragraph (c) to request approval from the Federal  Aviation Administration (FAA). This approval may address  either no action, if the current configuration eliminates  the unsafe condition, or different actions necessary to  address the unsafe condition described in this AD. Such a  request should include an assessment of the effect of the  changed configuration on the unsafe condition addressed by  this AD. In no case does the presence of any modification,  alteration, or repair remove any magneto from the  applicability of this AD.

NOTE 2: The FAA has received reports of some confusion as  to what is meant by S-20, S-1200, D-2000, and D-3000 series  magnetos as referenced in TCM Mandatory Service Bulletin  (MSB) No. MSB645, dated April 4, 1994, and this  airworthiness directive (AD). A typical example is S6RN-25,  where the S designates single type ignition unit (a D  designates a dual ignition unit), the 6 designates the  number of cylinders, the R designates right hand rotation,  the N is the manufacturer designation (this did not change  when TCM purchased the Bendix magneto product line), and the  number after the dash indicates the series (a -25 is a S-20  series magneto while a -3200 is a D-3000 series magneto,  etc.).

Compliance: Required as indicated, unless accomplished  previously.

To prevent magneto failure and subsequent engine  failure, accomplish the following:

(a) For magnetos with riveted or snap ring impulse  coupling assemblies, having less than 450 hours time in  service (TIS) since new, or overhaul, or since last  inspection, on the effective date of this AD, accomplish the  following:

(1) Prior to the accumulation of 500 hours TIS since  new, or overhaul, or since last inspection, inspect riveted  or snap ring impulse coupling assemblies for wear, and  replace, if necessary, prior to further flight, with  serviceable riveted or snap ring impulse coupling  assemblies, in accordance with the Detailed Instructions of  TCM MSB No. MSB645, dated April 4, 1994, and TCM SB No. 639,  dated March 1993.

(2) Thereafter, at intervals not to exceed 500 hours  TIS since the last inspection, inspect riveted or snap ring  impulse coupling assemblies for wear, and replace, if  necessary, prior to further flight, with serviceable riveted  or snap ring impulse coupling assemblies, in accordance with  the Detailed Instructions of TCM MSB No. MSB645, dated April  4, 1994, and TCM SB No. 639, dated March 1993.

(b) For magnetos with riveted or snap ring impulse  coupling assemblies, having 450 or more hours TIS since new,  or overhaul, or since last inspection, on the effective date  of this AD, or an unknown TIS on the effective date of this  AD, accomplish the following:

(1) Within the next 50 hours TIS after the effective  date of this AD, inspect riveted or snap ring impulse  coupling assemblies for wear, and replace, if necessary,  prior to further flight, with serviceable riveted or snap  ring impulse coupling assemblies in accordance with the  Detailed Instructions of TCM MSB No. MSB645, dated April 4,  1994, and TCM SB No. 639, dated March 1993.

(2) Thereafter, at intervals not to exceed 500 hours  TIS since the last inspection, inspect riveted or snap ring  impulse coupling assemblies for wear, and replace, if  necessary, prior to further flight, with serviceable riveted  or snap ring impulse coupling assemblies, in accordance with  the Detailed Instruction of TCM MSB No. MSB645, dated April  4, 1994, and TCM SB No. 639, dated March 1993.

(c) 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, Atlanta  Aircraft Certification Office. The request should be  forwarded through an appropriate FAA Maintenance Inspector,  who may add comments and then send it to the Manager,  Atlanta Aircraft Certification Office.

NOTE: Information concerning the existence of approved  alternative methods of compliance with this airworthiness  directive, if any, may be obtained from the Atlanta Aircraft  Certification Office.

(d) Special flight permits may be issued in accordance  with sections 21.197 and 21.199 of the Federal Aviation  Regulations (14 CFR 21.197 and 21.199) to operate the  aircraft to a location where the requirements of this AD can  be accomplished.

(e) The actions required by this AD shall be done in  accordance with the following TCM service documents:

This incorporation by reference was approved by the Director  of the Federal Register in accordance with 5 U.S.C. 552(a)  and 1 CFR part 51. Copies may be obtained from Teledyne  Continental Motors, P.O. Box 90, Mobile, AL 36601; telephone  (334) 438-3411. Copies may be inspected at the FAA, New  England Region, Office of the Assistant Chief Counsel, 12  New England Executive Park, Burlington, MA; or at the Office  of the Federal Register, 800 North Capitol Street, NW.,  suite 700, Washington, DC.

(f) This amendment becomes effective on July 18, 1996.

FOR FURTHER INFORMATION CONTACT:  Jerry Robinette, Aerospace Engineer, Atlanta Certification  Office, FAA, Small Airplane Directorate, Campus Building,  1701 Columbia Avenue, Suite 2-160, College Park, GA, 30337- 2748; telephone (404) 305-7371, fax (404) 305-7348.