[Federal Register Volume 61, Number 115 (Thursday, June 13, 1996)]
[Rules and Regulations]
[Pages 29934-29936]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-14869]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-ANE-07; Amendment 39-9649; AD 96-12-07]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Teledyne Continental Motors (TCM) (formerly Bendix) 
S-20, S-1200, D-2000, and D-3000 series magnetos equipped with impulse 
couplings, that currently requires inspections for wear, and 
replacement, if necessary, of the impulse coupling assemblies. This 
amendment requires replacement, if necessary, of worn riveted impulse 
coupling assemblies with serviceable riveted impulse couplings or snap 
ring impulse couplings. This amendment is prompted by the availability 
of an improved design for the impulse coupling assembly. The actions 
specified by this AD are intended to prevent magneto failure and 
subsequent engine failure.

DATES: Effective July 18, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 18, 1996.

ADDRESSES: The service information referenced in this AD may be 
obtained from Teledyne Continental Motors, P.O. Box 90, Mobile, AL 
36601; telephone (334) 438-3411. This information may be examined at 
the Federal Aviation Administration (FAA), New England Region, Office 
of the Assistant Chief Counsel, 12 New England Executive Park, 
Burlington, MA 01803-5299; or at the Office of the Federal Register, 
800 North Capitol Street, NW., suite 700, Washington, DC.

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.

SUPPLEMENTARY INFORMATION: On January 4, 1983, the Federal Aviation 
Administration (FAA) issued airworthiness directive (AD) 78-09-07 R3, 
Amendment 39-4538 (48 FR 1482, January 13, 1983), to require 
inspections for wear, and replacement, if necessary, of the impulse 
coupling assemblies on certain Teledyne Continental Motors (TCM) 
(formerly Bendix) S-20, S-1200, D-2000, and D-3000 series magnetos 
equipped with impulse couplings. That action was prompted by reports of 
numerous magneto failures. That condition, if not corrected, could 
result in magneto failure and subsequent engine failure.
    A proposal to amend part 39 of the Federal Aviation Regulations was 
published as a notice of proposed rulemaking (NPRM) in the Federal 
Register on September 21, 1993 (58 FR 48987). That NPRM would have 
retained the repetitive inspections for wear required by the current 
AD, but would have also required replacement, if necessary, of the 
riveted impulse coupling assembly with newly designed, improved, snap 
ring impulse coupling assemblies. In addition, the proposed AD would 
have required marking the magneto data plate to indicate installation 
of a snap ring impulse coupling assembly. Installation of snap ring 
impulse coupling assemblies would have constituted terminating action 
to the inspection requirements of this AD. That NPRM was prompted by 
the manufacturer redesigning the impulse coupling assembly to include 
snap ring fastening technology which strengthens the cam axle and 
reduces wear. The snap ring impulse coupling assembly was believed not 
to have the failure mode of the previous design.
    Since the issuance of that NPRM, the FAA received reports of snap 
ring impulse coupling assemblies being worn beyond limits. The FAA 
determined that it was necessary to reopen the proposal for public 
comment, so a Supplemental NPRM was published in the Federal Register 
on November 17, 1994 (59 FR 59391). That Supplemental NPRM proposed to 
retain the 500 hour repetitive inspections for wear required by the 
current AD, but would require these inspections for

[[Page 29935]]

magnetos equipped with snap ring impulse coupling assemblies as well.
    Since the issuance of that Supplemental NPRM, the FAA received 
comments that serviceable riveted impulse couplings should be permitted 
as replacement units as well as the snap ring design. The FAA 
concurred, since there has been no production of riveted impulse 
couplings since January 1992, distributors still have some left as this 
was a common, relatively high use item. The FAA determined that it was 
necessary to reopen the proposal for public comment, so a Supplemental 
NPRM was published in the Federal Register on October 16, 1995 (60 FR 
53558). That Supplemental NPRM proposed to require replacement of worn 
impulse couplings with serviceable impulse couplings of either riveted 
or snap ring design.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received since 
publication of the last Supplemental NPRM.
    Since the issuance of that Supplemental NPRM, the manufacturer has 
advised the FAA that the cost for replacement of the impulse coupling 
assembly has increased from $125 to $140. The economic analysis of this 
final rule has been revised accordingly.
    After careful review of the available data, the FAA has determined 
that air safety and the public interest require the adoption of the 
rule with the changes described previously. The FAA has determined that 
these changes will not increase the scope of the AD.
    The FAA estimates that 130,000 magnetos installed on aircraft of 
U.S. registry will be affected by this AD, that it will take 
approximately 1 work hour, plus 1 work hour to change the impulse 
coupling, and that the average labor rate is $60 per work hour. The 
average utilization of the fleet of these airplanes is estimated to be 
evenly divided between commercial/commuter service and private owners. 
The commercial/commuter service population is estimated to operate 500 
hours time in service (TIS) per year; therefore the cost to perform the 
inspections required by the AD will be approximately $3,900,000 per 
year. The FAA estimates that private owners operate their aircraft 
between 50 and 100 hours TIS per year; therefore it will take 
approximately 5 to 10 years to reach 500 hours time in service. The 
estimated cost for these owners will also be $3,900,000 spread over a 
time period of 5 to 10 years or 780,000 per year for 5 years or 
$390,000 for 10 years. The cost to replace the impulse coupling 
assembly is $140 per magneto plus one work hour at $60 per work hour 
for a total of $200 per magneto. While all the riveted impulse coupling 
assemblies will eventually have to be replaced, it is not possible to 
estimate the cost per year. The total cost for replacement for U.S. 
operators is estimated to be $26,000,000.
    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air Transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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.


Sec. 39.13    [Amended]

    2. Section 39.13 is amended by removing Amendment 39-4538 (48 FR 
1482, January 13, 1983) and by adding a new airworthiness directive, 
Amendment 39-9649, to read as follows:

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, 

[[Page 29936]]

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:

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         Document No.            Pages       Revision          Date     
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MSB No. MSB645................      1-6  Original.......  Apr. 4, 1994. 
  Total Pages: 6                                                        
SB No. 639....................      1-2  Original.......  Mar. 1993.    
  Total Pages: 2                                                        
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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.

    Issued in Burlington, Massachusetts, on May 29, 1996.
Robert E. Guyotte,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 96-14869 Filed 6-12-96; 8:45 am]
BILLING CODE 4910-13-U