[Federal Register Volume 60, Number 228 (Tuesday, November 28, 1995)]
[Proposed Rules]
[Pages 58580-58583]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-28956]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-ANE-44]
Airworthiness Directives; Textron Lycoming 235 Series, 290
Series, and Certain 320 and 360 Series Reciprocating Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to all Textron Lycoming 235 Series
and 290 Series, and certain 320 and 360 series reciprocating engines.
This proposal would require initial and repetitive inspections of the
crankshaft inner diameter (ID) for corrosion and cracks, and
replacement of cracked crankshafts with a serviceable part. This
proposal permits operation of engines with crankshafts that are found
to have corrosion pits but are free of cracks provided repetitive
inspections are performed until the next engine overhaul or 5 years
after the initial inspection, whichever occurs first, at which time
crankshafts with corrosion pits but no cracks must be replaced with
serviceable crankshafts. This proposal is prompted by reports of
crankshaft breakage originating from corrosion pits on the inside wall.
The actions specified by the proposed AD are intended to prevent
crankshaft failure, which can result in engine failure, propeller
separation, forced landing, and possible damage to the aircraft.
DATES: Comments must be received by January 29, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 94-ANE-44, 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 Textron Lycoming, 652 Oliver St., Williamsport, PA 17701;
telephone (717) 327-7080, fax (717) 327-7100. 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: Raymond Reinhardt, Aerospace Engineer,
New York Aircraft Certification Office, FAA, Engine and Propeller
Directorate, 10 Fifth St., Valley Stream, NY 11581-1200; telephone
(516) 256-7532, 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 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
[[Page 58581]]
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 94-ANE-44.'' 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. 94-ANE-44, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
On October 18, 1993, the Civil Aviation Authority (CAA), which is
the airworthiness authority of the United Kingdom, received a report
that a Piper PA-28-161 aircraft, with a Textron Lycoming O-320-D3G
reciprocating engine executed a forced landing due to an engine
crankshaft failure which caused the propeller to separate from the
aircraft. The cause of the crankshaft failure was determined to be due
to a high cycle reverse torsional fatigue mechanism that had initiated
from a number of corrosion pits in the crankshaft bore. After the
cracks had progressed through a substantial proportion of the
crankshaft section, the rate of advance had increased until the
remaining unseparated portion had failed as a result of overload. The
cracking occurred in high cycle fatigue and it had progressed over an
extended period of service. At the time of the accident the engine had
operated for 1,950 hours time in service (TIS) since overhaul and had
accumulated 4,429 hours TIS since new over a period of 16 years. In
addition, the Federal Aviation Administration (FAA) has received
reports of ten additional instances of cracks or failures of the
crankshaft behind the propeller flange on various Textron Lycoming
reciprocating engines due to cracks initiating from corrosion pits in
the crankshaft bore. This condition, if not corrected, could result in
crankshaft failure, which can result in engine failure, propeller
separation, forced landing, and possible damage to the aircraft.
The FAA has reviewed and approved the procedures for initial and
repetitive inspections of the crankshaft inner diameter (ID) for
corrosion and cracks contained in Textron Lycoming Mandatory Service
Bulletin (MSB) No. 505A, dated October 18, 1994, but has determined
that additional inspections via Fluorescent Penetrant Inspection (FPI)
are warranted if corrosion pits are found. The FPI inspection was
developed due to reports from Lycoming and other approved repair
stations that most of the crankshafts that are pitted do not contain
cracks. The FPI inspection was based on crack propagation data
developed by the FAA in conjunction with Textron Lycoming and the
technical base in the U.S. for performing Non-Destructive Inspections.
The FPI process has been shown to be reliable to detect cracks down to
0.050 inches deep and 0.100 inches long. The FPI inspection interval
was based on the crack propagation data and the detection of a crack
before the crankshaft failed. If a crankshaft is found to be pitted on-
wing, it is not recommended that removal of metal be permitted to
remove the corrosion pits due to possible contamination of the engine
oil supply with metal filings and also to ensure the concentricity of
the crankshaft is not compromised.
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require initial and repetitive inspections of the
crankshaft ID for corrosion and cracks, and replacement of cracked
crankshafts with a serviceable part. The actions would be required to
be accomplished in accordance with the MSB described previously and the
FPI procedure detailed in paragraph (e) of this AD.
There are approximately 77,100 engines of the affected design in
the worldwide fleet. The FAA estimates that 46,260 engines installed on
aircraft of U.S. registry would be affected by this proposed AD, that
it would take approximately 4 work hours per engine to accomplish the
proposed inspection, and that the average labor rate is $60 per work
hour. The estimated cost impact for the proposed inspections would be
$11,102,400. The FAA estimates 10% of the crankshafts will require
replacement at engine overhaul due to corrosion pits, and that it would
take 32 work hours per engine to replace pitted crankshafts. Required
parts would cost approximately $4,742 per engine. The estimated cost
for replacement of 10% of the crankshafts annually would be $3,081,841.
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 USC 106(g), 40101, 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Textron Lycoming: Docket No. 94-ANE-44
Applicability: Textron Lycoming 235 series, 290 series, 320
series except model O-320-B2C installed in helicopters, and 360
series except models O-360-A4G, -A4J, A4K, -A4M, -C4F, -AEIO-360-
B4A, HO-360 series, HIO-360 series, LHIO-360 series, VO-360 series,
and IVO-360 series, four-cylinder reciprocating engines with fixed
pitch propellers. These engines are installed on but not limited to
reciprocating engine powered aircraft manufactured by Cessna, Piper,
Beech, American Aircraft Corporation, Grumman American Aviation,
Mooney, Augustair Inc., Maule Aerospace Technology Corporation,
Great Lakes Aircraft Co., and Commander Aircraft Co.
Note: This airworthiness directive (AD) applies to each engine
identified in the preceding applicability provision, regardless of
whether it has been modified, altered, or
[[Page 58582]]
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 use the authority provided in paragraph (f) 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 engine from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent crankshaft failure, which can result in engine
failure, propeller separation, forced landing, and possible damage
to the aircraft, accomplish the following:
(a) For new engines shipped from Textron Lycoming prior to and
including December 31, 1984, that have never been overhauled, or any
remanufactured or overhauled engines that have accumulated 1,000
hours or more time in service (TIS) since remanufacture or overhaul,
initially inspect the inner diameter (ID) of the crankshaft for
corrosion pits within the next 100 hours TIS after the effective
date of this AD, or 6 months after the effective date of this AD,
whichever occurs first, in accordance with Textron Lycoming
Mandatory Service Bulletin (MSB) No. 505A, dated October 18, 1994.
The propeller, if installed, must be removed in accordance with the
aircraft manufacturer's procedures to perform this inspection. If
corrosion pits are found during this inspection, perform a
Fluorescent Penetrant Inspection (FPI) in accordance with paragraph
(e) of this AD.
(b) For new engines shipped from Textron Lycoming after December
31, 1984, that have never been overhauled, or any remanufactured or
overhauled engines that have accumulated less than 1,000 hours TIS
since remanufacture or overhaul, initially inspect the ID of the
crankshaft for corrosion pits, at intervals specified in
subparagraphs (1) through (3) of this paragraph, whichever occurs
first, in accordance with Textron Lycoming MSB No. 505A, dated
October 18, 1994. The propeller, if installed, must be removed in
accordance with the aircraft manufacturer's procedures to perform
this inspection. If corrosion pits are found during this inspection,
perform an FPI in accordance with paragraph (e) of this AD.
(1) At the next engine overhaul or disassembly.
(2) Within 10 years of the original ship date or 6 months from
the effective date of this AD whichever occurs later.
(3) At 1,000 hours TIS since remanufacture or overhaul, or 6
months from the effective date of this AD, whichever occurs later.
(c) Thereafter, if no corrosion pits are found on the ID of the
crankshaft during the initial inspection, perform an inspection at
intervals not to exceed 5 years since last inspection or at the next
engine overhaul or disassembly, whichever occurs first, in
accordance with Textron Lycoming MSB No. 505A, dated October 18,
1994. If corrosion pits but no cracks are found on the ID of the
crankshaft during the initial inspection, repeat the FPI at
intervals not to exceed 100 hours TIS since last FPI inspection, 5
years from the initial inspection that detected the corrosion pits,
or next engine overhaul, whichever occurs first.
(d) Prior to further flight, remove from service and replace
with a serviceable part the following:
(1) Crankshafts found cracked during FPI outlined in paragraph
(e) of this AD.
(2) Crankshafts that have corrosion pits but no cracks, which
are on a repetitive inspection cycle and have attained 5 years from
the initial inspection that detected the corrosion pits, in
accordance with Textron Lycoming MSB No. 505A, dated October 18,
1994.
(3) Crankshafts that have corrosion pits but no cracks, which
are being overhauled.
(e) An engine as installed in the aircraft having a corroded
crankshaft may be returned to service without disassembly provided
an FPI confirms the bore to be crack free. The process and materials
utilized for the FPI are in accordance with the classification
contained in MIL-I-25135. The FPI must be fluorescent solvent
removable (Method C) utilizing a Type 1 penetrant system with a
penetrant sensitivity Level 3 or higher and a Form D-Nonaqueous
Developer. Spray containers of the materials are acceptable for this
inspection. Personnel performing the FPI that are making accept/
reject decisions shall be qualified to at least Level II in liquid
penetrant inspection in accordance with MIL-STD-410E, dated January
25, 1991 or a similar certification system assuring the competence
of the inspector. This FPI process involves the removal of penetrant
material from the inspection surface. Caution must be used to ensure
that contaminants from the cleaning process and the FPI do not enter
the engine oil supply by blocking off the area of the crankshaft
bore that is aft of the area being inspected by using a clean, dry,
lint-free cloth. The FPI must be performed using the following
steps:
(1) Cleaning--The crankshaft bore surface must be cleaned of
visible corrosion prior to the FPI process using Scotchbrite or an
equivalent material. Metal-removing processes must not be used for
visible corrosion cleaning. In addition, clean all surfaces to be
inspected utilizing a cleaner, such as Magnaflux Spot Check Cleaner/
Remover SKC-NF or equivalent, on the ID of the crankshaft bore. Let
the cleaner/remover dry for 5 minutes minimum. Wipe clean with a
lint- free cloth.
(2) Penetrant Application--Spray penetrant, such as ZYGLO ZL-22A
Magnaflux Corp. or equivalent Type 1 with a penetrant sensitivity
Level 3 or higher, on the ID bore.
(3) Penetrant Dwell--Allow a minimum of 10 minutes dwell. For
dwell times exceeding 60 minutes the penetrant shall be reapplied to
prevent drying.
(4) Penetrant Removal--Remove all bulk surface penetrant by
wiping with a clean, dry lint-free cloth. Make a single wipe and
then fold the cloth to provide a clean surface for succeeding wipes.
(i) Solvent Wipe--After the bulk of the surface penetrant has
been removed, lightly moisten a fresh lint-free cloth with cleaner/
remover and again wipe the surface. The cloth must not be saturated
and the inspection surface must not be flooded with solvent.
Excessive solvent will wash penetrant from defects.
(ii) During wiping, the inspection surface shall be illuminated
with black light. Repeat the solvent wipe as necessary until no
residual trace of penetrant remains on the inspection surface.
(5) Nonaqueous Developer (solvent suspended)--Following the
cleaner/remover wipe apply nonaqueous developer by spraying a
developer, such as Magnaflux Spot Check Developer SKD-NF or Form D-
Nonaqueous equivalent, on the ID bore. Apply a thin uniform layer to
the bore surface. The optimum coating thickness is indicated by the
visibility of the part surface. If the metallic luster cannot be
seen the developer is too thick.
(6) Dwell--Developer dwell is required to allow the developer
time to draw entrapped penetrant from any small defects. The minimum
development time shall be 10 minutes. The maximum dwell time for
nonaqueous developer shall be 60 minutes.
(7) Inspection shall be performed within the allotted dwell
time. Components that are not inspected within the allotted dwell
time must be reprocessed.
(i) Examine crankshaft bore in a darkened enclosure under
ultraviolet (black) light. Allow 1 minute for eyes to adapt to
darkened environment prior to inspecting crankshaft bore. Use of
photochromic lenses or permanent darkened lenses is prohibited.
(ii) During inspection make sure that the black light intensity
is a minimum of 1200 microwatts/cm2 at the bore surface. This
can be accomplished by positioning the black light as close as
necessary to the bore to achieve 1200 microwatts/cm2. White
light background shall not exceed 20 1x/m2 (2 foot-candles). A
photographic light meter may be used to determine the white light
background reading.
(iii) Crankshaft bores having no crack indications are
acceptable.
(iv) Magnification (10X maximum) and/or white light may be used
to determine discontinuity type. Indications, on parts exhibiting
fluorescent background which interferes with evaluation of
questionable indications, shall be evaluated as follows:
(A) Lightly wipe the area once with a soft brush or cotton swab
applicator dampened with ethyl alcohol. Do not permit alcohol to
flood the surface.
(B) After the alcohol evaporates from the surface, re-inspect.
If an indication reappears, evaluate it immediately. If the
indication does not reappear, reapply developer . The redevelopment
time shall equal the original development time. Thereafter, re-
inspect.
(8) After inspection, clean residual penetrants and developers
from crankshaft bore. Ensure lint-free cloth is removed from
crankshaft bore prior to installing front crankshaft plug. Failure
to do so may result
[[Page 58583]]
in oil restriction within the engine and in turn cause engine failure.
(f) 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. The request should be forwarded through an appropriate FAA
Maintenance Inspector, who may add comments and then send it to the
Manager, New York 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 New York Aircraft Certification
Office.
(g) 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 November 8, 1995.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 95-28956 Filed 11-27-95; 8:45 am]
BILLING CODE 4910-13-P
