[Federal Register Volume 60, Number 199 (Monday, October 16, 1995)]
[Proposed Rules]
[Pages 53557-53560]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-25567]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-ANE-07]


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This notice revises an earlier proposed 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equipped with impulse couplings, that would have superseded an AD that 
currently requires inspections for wear, and replacement, if necessary, 
of the impulse coupling assemblies. The proposed rule would have 
retained the repetitive inspections for wear required by the current 
AD, but would have also required replacement, if necessary, of riveted 
impulse coupling assemblies 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 the AD. That proposal was prompted by 
availability of an improved design for the impulse coupling assembly. 
This action revises the proposed rule by allowing installation of 
replacement serviceable riveted as well as snap ring impulse couplings. 
The actions specified by this proposed AD are intended to prevent 
magneto failure and subsequent engine failure.

DATES: Comments must be received by December 15, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 93-ANE-07, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location between 8:00 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 Teledyne Continental Motors, P.O. Box 90, Mobile, AL 
36601; telephone (334) 438-3411. This information may be examined at 
the FAA, New England Region, Office of the Assistant Chief Counsel, 12 
New England Executive Park, Burlington, MA.

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.
    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 notice 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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 93-ANE-07.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 93-ANE-07, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    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 magnetos equipped 
with snap ring impulse coupling assemblies as well.
    Since the publication of that Supplemental NPRM, the FAA has 
received comments. One commenter supports the AD as written. The other 
two commenters state that they basically support the AD, but feel that 
serviceable riveted impulse couplings should be permitted as 
replacement units as well as the snap ring design. The FAA concurs, 
while there has been no production of riveted impulse couplings since 
January 1992, distributors may still have some left as this was a 
common, relatively high use item. This new Supplemental NPRM has 
therefore been revised to propose replacement of worn impulse couplings 
with serviceable impulse couplings of either design.

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    Since this change expands the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.
    The FAA has reviewed and approved the technical contents of TCM 
Mandatory Service Bulletin (MSB) No. MSB645, dated April 4, 1994, that 
describes procedures for inspection of the impulse coupling assemblies 
for wear; and TCM SB No. 639, dated March 1993, that clarifies 
procedures for installation of impulse coupling assemblies.
    The FAA estimates that 130,000 magnetos would be affected by this 
proposed AD, that the required inspection would take 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 
proposed AD would 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 
would 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 $125 per magneto plus one work 
hour at $60 per work hour for a total of $185 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 would be $24,050,000.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Teledyne Continental Motors: Docket No. 93-ANE-07.

    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 

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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.

    Issued in Burlington, Massachusetts, on October 3, 1995.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 95-25567 Filed 10-13-95; 8:45 am]
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