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Proposal to revise definition of Prop Strike in AD91-14-22

Steve Pierce

BENEFACTOR
Graham, TX
If you want to weed through the BS skip to the definition of a Prop Strike.


APPLICABILITY: This airworthiness directive (AD) is applicable to all
Textron Lycoming direct-drive reciprocating engines except O- 145, O-320H,
O-360E, LO-360E, LTO-360E, TO-360E, O-435, and TIO-541 series engines.

NOTE 1: This 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 (d) 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: Compliance with this AD is required as indicated before
further flight if the engine has experienced a propeller strike as defined
in paragraph (b) of this AD, unless already done.

To prevent loosening or failure of the crankshaft gear retaining bolt,
which may cause sudden engine failure, do the following:

(a) Inspect, and if necessary repair, the crankshaft counterbored recess,
the alignment dowel, the retaining bolt and lock plate, the bolt
hole threads, and the crankshaft gear for wear, galling,
corrosion, and fretting in accordance with steps 1 through 7
of Textron Lycoming Mandatory Service Bulletin No. 475C, dated
January 30, 2003.

DEFINITION OF PROPELLER STRIKE

(b) For the purposes of this AD, a propeller strike is defined as follows:

(1) Any incident, whether or not the engine is operating, that requires
repair to the propeller other than minor dressing of the blades.

(2) Any incident during engine operation in which the propeller impacts a
solid object that causes a drop in revolutions per minute (RPM) and
also requires structural repair of the propeller (incidents
requiring only paint touch-up are not included). This is not
restricted to propeller strikes against the ground.

(3) A sudden RPM drop while impacting water, tall grass, or similar
yielding medium, where propeller damage is not normally incurred.

(c) The preceding definitions include situations where an aircraft is
stationary and the landing gear collapses causing one or more blades
to be substantially bent, or where a hanger door (or other object)
strikes the propeller blade. These cases should be handled as sudden
stoppages because of potentially severe side loading on the
crankshaft flange, front bearing, and seal.

ALTERNATIVE METHODS OF COMPLIANCE

(d) 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
(NYACO). Operators must submit their request through an appropriate
FAA Principal Maintenance Inspector, who may add comments and then
send it to the Manager, NYACO.

NOTE 2: Information concerning the existence of approved alternative
methods of compliance with this airworthiness directive, if any, may be
obtained from the NYACO.

SPECIAL FLIGHT PERMITS

(e) Special flight permits may be issued in accordance with Sec. Sec.
21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197
and 21.199) to operate the airplane to a location where the
requirements of this AD can be done.

Issued in Burlington, Massachusetts, on March 17, 2003. Robert G. Mann,
Acting Manager, Engine and Propeller Directorate, Aircraft Certification
Service.

[FR Doc. 03-6998 Filed 3-24-03; 8:45 am]

DATES: Comments must be received by May 27, 2003.
PREAMBLE
--------------------------------------------------------------------------------


DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION

14 CFR Part 39

[Docket No. 89-ANE-10-AD]

AIRWORTHINESS DIRECTIVES; Textron Lycoming, Direct-Drive
Reciprocating Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The Federal Aviation Administration (FAA) proposes to
supersede an existing airworthiness directive (AD), applicable to
Textron Lycoming, direct-drive reciprocating engines (except O-145, O-
320H, O-360E, LO-360E, LTO-360E, O-435, and TIO-541 series engines).
That AD currently requires inspection of the crankshaft gear
installation and rework or replacement of the gears where necessary
after a propeller strike, sudden stoppage, at overhaul, or whenever
gear train repair is required. This proposal would revise the
definitions for sudden stoppage and propeller strike. This proposal is
prompted by a change to the definition of a propeller strike or sudden
stoppage. The actions specified in the proposed AD are intended to
prevent loosening or failure of the crankshaft gear retaining bolt,
which may cause sudden engine failure.

DATES: Comments must be received by May 27, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional Counsel,
Attention: Rules Docket No. 89-ANE-10-AD, 12 New England Executive Park,
Burlington, MA 01803-5299. Comments may also be sent via the Internet
using the following address: 9-ane-adcomment@faa.gov.

Comments sent via the Internet must contain the docket number in the
subject line. Comments may be inspected at this location between 8 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 Textron Lycoming, 652 Oliver Street, Williamsport, PA
17701, U.S.A. This information may be examined at the FAA, New England
Region, Office of the Regional Counsel, 12 New England Executive Park,
Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Norm Perenson, Aerospace Engineer, New
York Aircraft Certification Office, FAA, Engine and Propeller
Directorate, 10 Fifth Street, 3rd floor, Valley Stream, NY 11581-1200;
telephone (516) 256-7537; fax (516) 568-2716.

SUPPLEMENTARY INFORMATION:

COMMENTS INVITED

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 action 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 action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 89-ANE-10-AD.'' The postcard will be date stamped and
returned to the commenter.

AVAILABILITY OF NPRM'S

Any person may obtain a copy of this NPRM by submitting a request to
the FAA, New England Region, Office of the Regional Counsel,
Attention: Rules Docket No. 89-ANE-10-AD, 12 New England Executive
Park, Burlington, MA 01803-5299.

DISCUSSION

On July 12, 1991, the FAA issued AD 91-14-22, Amendment 39-6916 (56 FR
33205, July 19, 1991), to require inspection of the crankshaft gear
installation and rework or replacement of the gears where necessary
during overhaul, after a propeller strike, sudden stoppage, or
whenever gear train repair is required. That action was prompted by
reports of loosening and disengagement of the gear retaining bolt
which could result in loss of the main camshaft drive train and
critical engine accessories. That condition, if not corrected, could
result in loosening or failure of the crankshaft gear retaining bolt,
which may cause sudden engine failure.

Since AD 91-14-22 was issued, Textron Lycoming has issued mandatory
Service Bulletin (SB) No. 475C, dated January 30, 2003, and the
definition of a propeller strike has been expanded to include:

? Any incident, whether or not the engine is operating, that requires
repair to the propeller beyond minor dressing of the blades.

? A sudden drop in engine revolutions per minute (RPM) while impacting
water, tall grass, or similar yielding medium where propeller damage
is not normally incurred.

Textron Lycoming has also included instructions in the maintenance
manuals for inspections at overhaul and whenever repair of the gear
train is required.

MANUFACTURER'S SERVICE INFORMATION

The FAA has reviewed and approved the technical contents of Textron
Lycoming Mandatory Service Bulletin (MSB) No. 475C, dated January 30,
2003, that describes procedures for inspection and repair of the
crankshaft and gear assembly.

FAA'S DETERMINATION OF AN UNSAFE CONDITION AND PROPOSED ACTIONS

Since an unsafe condition has been identified that is likely to exist
or develop on other Textron Lycoming direct-drive reciprocating
engines of this same type design, the proposed AD would supersede AD
91-14-22 to revise the definitions of a propeller strike and sudden
engine stoppage. The actions must be done in accordance with the
service information described previously.

ECONOMIC ANALYSIS

There are approximately 175,000 Textron Lycoming, direct-drive
reciprocating engines of the affected design in the worldwide fleet.
The FAA estimates that 125,000 engines installed on aircraft of U.S.
registry would be affected by this proposed AD. The FAA also estimates
that it would take approximately 7 work hours per engine to accomplish
the proposed actions, and that the average labor rate is $60 per work
hour. Required parts would cost approximately $420 per engine. Based
on these figures, the total cost of the proposed AD to U.S. operators
is estimated to be $52,500,000.

REGULATORY ANALYSIS

This proposed rule does not have federalism implications, as defined
in Executive Order 13132, because it 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. Accordingly,
the FAA has not consulted with state authorities prior to publication
of this proposed rule.

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), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing Amendment 39-6916 (56 FR
33205, July 19, 1991), and by adding a new airworthiness directive, to
read as follows:
 
ought to make annualing A/C with Lycomings interesting
Disclaimer: All owners must pass lie detector test verifying you never landed in tall grass/ deep snow before annual will be signed off
 
Looks like they are bending over the IA's again. Now, in theory, wouldn't this reduce Lycoming's corporate liability, thus reducing their insurance costs, with savings that can be passed on to the consumer? Wait, my bad somehow, costs will still go up...as will the cost of the annual (that one for good reason) Funny how that works.
Bill
 
Doesn't differentiate between wood and metal propeller either...
 
Steve
Did you type all that AD, in ypur post or is there another way to get it in. Your a hell of a typest if you typed it. I have an interesting article I wanted to post somewhere, but it would take me all day to type it.

Tim
 
No, I didn't type it. I got the text off the T-Data web-site. They provide CD's of all current ADs and service bulletins along with a daily updated website of new and proposed ADs. I cut and pasted it by rt clicking the mouse.
 
Isn't there a definition somewhere about what constitutes "a sudden RPM drop"? How many RPM? How "sudden"?

For that matter, how tall is "tall grass"?

I hate subjective laws!
 
Rod..........most likely they will come up with something like "any grass up to but not including 12.487 inches in length when measured from base to tip while streched to its maximum length as measured by a federally certificated technician using an approved measuring device that has been calibrated by an authorized agency within the preceeding 60 days"
Of course broadleaf weeds would fall under a separate category.
 
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