[Federal Register Volume 64, Number 27 (Wednesday, February 10, 1999)]
[Rules and Regulations]
[Pages 6516-6518]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-3039]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-81-AD; Amendment 39-11028; AD 99-04-04]
RIN 2120-AA64


Airworthiness Directives; Textron Lycoming Reciprocating Engines 
IO-540 and O-540 Engines Equipped With Slick Aircraft Products Magnetos

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to Textron Lycoming IO-540 and O-540 engines equipped 
with Slick Aircraft Products magnetos. This action requires removal of 
the Slick magneto from the engine and inspection of the impulse 
coupling pawl for wear. This amendment is prompted by several service 
difficulty reports, two incidents, and an accident involving severely 
worn and failed impulse couplings. The actions specified in this AD are 
intended to prevent failure of the magneto impulse coupling, resulting 
in seizure of the engine.

DATES: Effective February 25, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 25, 1999.
    Comments for inclusion in the Rules Docket must be received on or 
before April 12, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 98-ANE-81-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ad-
[email protected].'' Comments sent via the Internet must contain the 
docket number in the subject line.
    The service information referenced in this AD may be obtained from 
Textron Lycoming, 652 Oliver Street, Williamsport, PA 17701. This 
information may be examined at the FAA, New England Region, Office of 
the Regional 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.

FOR FURTHER INFORMATION CONTACT: Rocco Viselli, Aerospace Engineer, New 
York Aircraft Certification Office, FAA, Engine & Propeller 
Directorate, 10 Fifth Street, 3rd Floor, Valley Stream, NY 11581-1200; 
telephone (516) 256-7531, fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: The Federal Aviation Administration (FAA) 
has received numerous reports of failure of the impulse coupling pawl 
on Slick Aircraft Products magnetos installed on certain Textron 
Lycoming IO-540 and O-540 engines that resulted in seizure of the 
engine. In one accident, a Piper Cherokee Six airplane equipped with a 
Textron Lycoming IO-540 series engine experienced an engine failure. 
The left magneto, Slick model number 6531, equipped with impulse 
coupling Slick P/N M3333, seized within the housing. The seizure of the 
left magneto caused

[[Page 6517]]

the gear drive train to fail. The failure of the gear drive train 
caused the right magneto to stop operating, which caused the engine to 
stop. In one incident, a magneto seized when one pawl jammed under the 
second pawl due to a loose or broken rivet. The seizure resulted in a 
forced landing. In another incident, a Piper PA-32 experienced a 
reduction in engine power while in cruise flight. Examination of the 
engine revealed that the left magneto coupling drive gear had 
disintegrated and sheared several drive gear teeth. There have also 
been a number of Service Difficulty Reports of severely worn and failed 
impulse couplings on certain Textron Lycoming O-540 and IO-540 series 
reciprocating engines equipped with Slick Aircraft Products magneto 
model numbers 6251, 6252, 6255, 6351 and 6355. Investigation results 
suggest that excessive vibration or radial forces acting on the impulse 
coupling assembly may be causing unusually rapid wear of the impulse 
coupling pawl. In these cases, the impulse coupling may improperly 
engage the stop pins when the engine is operating, and cause damage to 
the accessory drive gear and impulse coupling. Possible causes of 
failed impulse couplings that are currently under investigation include 
unusually rapid wear due to excessive vibratory forces, improper 
crankcase overhaul in magneto bore location, and lack of routine 
magneto inspection and maintenance. This condition, if not corrected, 
could result in failure of the magneto impulse coupling, resulting in 
seizure of the engine.
    The FAA has reviewed and approved the technical contents of Textron 
Lycoming Mandatory Service Bulletin (SB) No. 537, dated November 20, 
1998. Textron Lycoming SB No. 537 reprints the Slick Aircraft Product 
SB SB1-98, dated August 26, 1998, that describes procedures for the 
inspection of the impulse coupling pawls for wear and proper operation 
and, if necessary, replacement of the impulse coupling assembly.
    Since an unsafe condition has been identified that is likely to 
exist or develop on certain other Textron Lycoming IO-540 and O-540 
engines of the same type design, this AD is being issued to prevent 
failure of the magneto impulse coupling, resulting in seizure of the 
engine. This AD requires an initial inspection of the magneto impulse 
coupling assembly pawls for wear either within the next 10 hours of 
time in service (TIS) from the effective date of this AD if the magneto 
has been in service for more than 250 hours TIS since new or overhauled 
or if the service history of the magneto is unknown, or within the next 
10 hours of TIS from the effective date of this AD or by 250 hours TIS 
since new or overhauled whichever is later if the magneto has been in 
service for less than 250 hours TIS since new or overhauled; and then 
repetitive inspections every 250 hours TIS from the last inspection or 
overhaul of the magneto. The actions are required to be accomplished in 
accordance with the SB described previously. A final, terminating 
action cannot be defined until the investigation is completed.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD 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 98-ANE-81-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a ``significant regulatory action'' 
under Executive Order 12866. It has been determined further that this 
action involves an emergency regulation under DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979). If it is determined 
that this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket. A copy of it, if filed, 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 adding the following new 
airworthiness directive:

99-04-04  Textron Lycoming: Amendment 39-11028. Docket 98-ANE-81-AD.

    Applicability: Textron Lycoming O-540-B2B5, B2C5, E4B5, E4C5, 
G1A5, G2A5, IO-540-K1A5, K1B5, and K1G5 reciprocating model engines 
equipped with Slick Aircraft Products magneto model numbers 6251, 
6252, 6255, 6351 and 6355. These engines are installed on, but not 
limited to, the following airplanes: Britten Norman BN-2A, -2A-2, -
2A-3, -2A-6, -2A-9, -2A-20, -2A-21, -2A-26, -2A-27, -2A-MKIII, -2A-
MKIII-2, -2A-MKIII-3, -2B-20, -2B-21, -2B-26,

[[Page 6518]]

-2B-27 and Piper PA-25-235, PA-25-260, PA-32-260, PA-32-300.

    Note 1: This airworthiness directive (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 (e) 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: Required as indicated, unless accomplished 
previously.
    To prevent failure of the magneto impulse coupling, resulting in 
seizure of the engine, accomplish the following:
    (a) For engines on which the service history of the magneto is 
not known, or on which the magneto has greater than 250 hours TIS 
since new, factory rebuilt, or overhauled, on the effective date of 
this AD, within 10 hours of the effective date of this AD, inspect 
the components of the magneto impulse coupling for the conditions 
listed in accordance with steps 1 through 7 of the Textron Lycoming 
Mandatory SB No. 537, dated November 20, 1998.

    Note 2: The Textron Lycoming Mandatory SB No. 537 dated November 
20, 1998 contains the Slick SB No. SB1-98 dated August 26, 1998 in 
its entirety. The steps referenced to the Textron Lycoming SB No. 
537 dated November 20, 1998 by this compliance section are the same 
steps that are contained in the Slick SB No. SB1-98 dated August 26, 
1998.

    (b) For engines on which the magneto has less than or equal to 
250 hours TIS since new, factory rebuilt, overhauled on the 
effective date of this AD, before accumulating 250 hours TIS since 
new, factory rebuilt or overhauled, or within 10 hours TIS from the 
effective date of this AD, whichever comes later, inspect the 
components of the magneto impulse coupling for the conditions listed 
in accordance with steps 1 through 7 of the Textron Lycoming 
Mandatory SB No. 537, dated November 20, 1998.
    (c) Thereafter, at intervals not to exceed 250 hours TIS since 
the last inspection performed in accordance with this AD, inspect 
the components of the magneto impulse coupling for the conditions 
listed in accordance steps 1 through 7 of the Textron Lycoming 
Mandatory SB No. 537, dated November 20, 1998.
    (d) Remove magneto impulse coupling before 2,000 hours TIS since 
new and replace with a serviceable part.
    (e) 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. Operators shall submit their requests through an appropriate 
FAA Principal Maintenance Inspector, who may add comments and then 
send it to the Manager, New York Aircraft Certification Office.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the New York Aircraft Certification 
Office.

    (f) The inspection shall be done in accordance with the 
following Textron Lycoming Mandatory SB:

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            Document No.                      Pages                 Revision                     Date
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SB No. 537..........................  1-9..................  Original..............  Nov. 20, 1998.
Total pages: 9......................
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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 Textron Lycoming, 652 Oliver Street, 
Williamsport, PA 17701. Copies may be inspected at the FAA, New England 
Region, Office of the Regional 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.
    (g) This amendment becomes effective on February 25, 1999.

    Issued in Burlington, Massachusetts, on February 1, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-3039 Filed 2-9-99; 8:45 am]
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