[Federal Register Volume 63, Number 18 (Wednesday, January 28, 1998)]
[Rules and Regulations]
[Pages 4154-4157]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-1705]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-ANE-44; Amendment 39-10291; AD 98-02-08]
RIN 2120-AA64
Airworthiness Directives; Certain Textron Lycoming 320 and 360
Series Reciprocating Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Textron Lycoming 320 and 360 series reciprocating
engines, that requires visual inspections of the inside diameter (ID)
of the crankshaft for corrosion pits, and if corrosion pits are found
during this inspection, prior to further flight, performing a magnetic
particle inspection (MPI) or fluorescent penetrant inspection (FPI) of
the ID for cracks. In addition, this AD requires reporting findings of
inspections to the FAA. Finally, terminating action to the inspections
of this AD is the application of a preventive treatment coating on non-
corroded crankshafts to prevent corrosion. This amendment is prompted
by reports of cracks in crankshafts originating from corrosion pits in
the ID. The actions specified by this AD are intended to prevent
crankshaft failure, which can result in engine failure, propeller
separation, forced landing, and possible damage to the aircraft.
DATES: Effective March 30, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 30, 1998.
ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (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 or Raymond Reinhardt ,
Aerospace Engineers, New York Aircraft Certification Office, FAA,
Engine and Propeller Directorate, 10 Fifth St., Valley Stream, NY
11581-1200; telephone (516) 256-7531 , fax (516) 568-2716.
SUPPLEMENTARY INFORMATION: On October 18, 1993, the Civil Aviation
Authority (CAA), which is the airworthiness authority of the United
Kingdom (UK), received a report that a Piper PA-28-161 aircraft, with a
Textron Lycoming O-320-D3G reciprocating engine installed, 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 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 total time since new over a period of 16 years.
In addition, the Federal Aviation Administration (FAA) has confirmed
that four other failures in the United States and 10 in foreign
countries were due to cracks initiating from corrosion pits in the
crankshaft bore on certain Textron Lycoming 320 and 360 reciprocating
engines with ratings of 160 horsepower or greater. Of the 10 failures
in foreign countries, four resulted in the propeller separating from
the aircraft inflight. Three of these four were from 1993 to 1996. The
FAA utilized metallurgical failure analysis reports and other
information to conclude that these failures were due to cracks
originating from corrosion pits. 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.
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to include an AD that would
[[Page 4155]]
apply to Textron Lycoming 235 Series and 290 Series, and certain 320
and 360 series reciprocating engines, was published in the Federal
Register on November 28, 1995 (60 FR 58580); the comment period was
reopened in a reprinting of the original proposal on April 8, 1996 (61
FR 15430). That action proposed to require initial and repetitive
inspections of the crankshaft inside diameter (ID) for corrosion and
cracks, and replacement of cracked crankshafts with a serviceable part.
In addition, the proposed AD would have permitted operation of engines
with crankshafts that were found to have corrosion pits but were free
of cracks provided repetitive inspections were performed until the next
engine overhaul or 5 years after the initial inspection, whichever
occurred first, at which time the proposed AD would have required those
crankshafts with corrosion pits but no cracks to be replaced. Those
proposed actions would be performed in accordance with Textron Lycoming
Mandatory Service Bulletin (MSB) No. 505A, dated October 18, 1994.
The FAA had determined that fluorescent penetrant inspections (FPI)
were warranted if corrosion pits were found. The FPI inspection program
was developed due to reports from Textron Lycoming and other approved
repair stations that most of the crankshafts that are pitted do not
contain cracks. The FAA determined that visual inspections alone were
not sufficient to detect a crack. The FPI inspection was based on crack
propagation data developed by the FAA in conjunction with Textron
Lycoming and with consideration of the technical base in the U.S. for
performing nondestructive inspections. The FPI process was shown to be
reliable for detection of cracks down to 0.050 inches in depth and
0.100 inches in length. The FPI inspection interval was based on the
crack propagation data such that a crack could be reliably detected
before the crankshaft failed. If an installed engine was found to have
a pitted crankshaft, the FAA did not propose to allow the removal of
metal to remove the corrosion pits due to possible contamination of the
engine oil supply with metal filings and to ensure that the
concentricity of the crankshaft would not be compromised.
Interested persons were afforded an opportunity to participate in
the making of this amendment. Over 200 comments were received in
response to the initial NPRM. In addition, the FAA met with the
Aircraft Owners and Pilots Association (AOPA), Aeronautical Repair
Station Association (ARSA), and Textron Lycoming to discuss the data
that formed the basis for this action. A summary of that meeting is
contained in the docket file.
A Supplemental Notice of Proposed Rulemaking (SNPRM), in response
to the comments, was published in the Federal Register on January 3,
1997 (62 FR 343). That SNPRM fully addressed the comments received in
response to the NPRM and the issues raised at the meeting with AOPA,
ARSA, and the manufacturer. That action proposed to revise the proposal
by limiting the applicability of the proposed AD to only certain
Textron Lycoming 320 and 360 series reciprocating engines, excluding
additional engines installed in helicopters; permitting any
certificated mechanic holding an airframe or powerplant rating to
perform the FPI; permitting continued use of a pitted crankshaft as
long as repetitive FPI inspections are performed; and deleting the five
year limit on the use of crankshafts that are pitted but not cracked.
Also, the FAA received new cost information, and revised the economic
analysis with respect to the initial inspection time, the time to
remove and replace crankshafts, the cost of the replacement
crankshafts, and the cost for repetitive FPI inspections. Finally, the
revised proposal introduced a public reporting survey to provide the
FAA with a broader database on the condition of crankshafts when
observed during the initial inspections.
Twenty-one comments were received in response to the SNPRM. Due
consideration has been given to the comments received.
Seven commenters state that there have not been enough crankshaft
failures to justify the AD, that the proposed actions are too costly,
and that the FAA should acquire more data before promulgating this
rule. The FAA does not concur. As stated in the SNPRM, the FAA received
data and studies that substantiated the need for an AD. These studies
and data confirm the crankshaft fracture occurred at a stress
concentration caused by a corrosion pit on the inside of the
crankshaft. In addition, since the NPRM was issued, six additional
crankshaft failures on 160 horsepower Textron Lycoming engines are
being investigated. The FAA has, however, performed additional analysis
to limit the population of engines impacted by this proposed AD and has
deleted the five year limit on pitted crankshafts undergoing repetitive
FPI inspections. These measures will decrease the cost of the AD to the
public.
Two commenters state that the corrosion problem is caused by a
design flaw; i.e., the crankshafts should be solid instead of hollow.
The FAA does not concur. A coating has been incorporated on the inside
bore of new crankshafts shipped in engines and as spares from Textron
Lycoming since February 15, 1997. Textron Lycoming has issued Service
Bulletin (SB) No. 530 dated December 1, 1997, which describes applying
Urethabond 104 as a protective coating on the inside bore of the
crankshafts. This coating should only be applied during overhaul due to
the preparation requirement of degreasing the inside bore prior to the
application of the coating.
One commenter states that a dye penetrant inspection should be
performed in lieu of the FPI, as it is more accurate in detecting
cracks. The FAA does not concur. Dye penetrant actually includes both
visible dye and fluorescent dye penetrant techniques. Recent use of the
term within the inspector community has limited the meaning to visible
dye penetrant. The reliability of inspection data available to the FAA
indicates that FPI has a better probability of detection than visible
dye penetrant (color contrast) inspection. The preferred dye penetrant
inspection method is the FPI method.
One commenter states that a magnetic particle inspection
(Magnaflux) should be performed in lieu of the FPI, as it is more
accurate in detecting cracks. The FAA concurs in part. The magnetic
particle inspection (MPI) is the preferred method with the shaft
removed from the engine at overhaul. An FPI should only be performed if
the crankshaft is installed in the engine such as during an on-wing
inspection. An MPI should not be performed with the crankshaft
installed in the engine due to the difficulty in obtaining a suitable
magnetic field. In addition, the residual field effects after the
demagnetization process may have a harmful effect on the rotating
components in the engine, including the bearings.
One commenter states that the AD should take into consideration the
operation and service history for each engine in specifying corrective
action. The FAA partially concurs. The FAA has taken into consideration
service history and has limited the applicability of this AD to engines
with 160 hp or greater. The survey to be completed for the initial
inspection of the crankshaft may aid the FAA in determining other
causal effects which may be used for future rulemaking.
Five commenters state that the AD should require application of a
preventive treatment on the inside bore of the crankshaft to prevent
future corrosion. The FAA concurs. Textron
[[Page 4156]]
Lycoming has developed a preventive treatment known as Urethabond 104
and has issued MSB No. 530, dated December 1, 1997, which describes
procedures for applying this coating. Crankshafts that are confirmed to
have the letters ``PID'' stamped on the outside diameter of the
propeller flange (PID stands for Painted Internal Diameter), do not
require the inspection requirements of this AD. The application of the
Urethabond 104 coating constitutes terminating action for the
inspection requirements of this AD.
One commenter states that the FAA should impose a life limit of
4,000 hours time in service on all affected crankshafts. The FAA does
not concur. To date, the FAA has no data from Textron Lycoming nor from
any other source which would substantiate a 4,000 hour time in service
life limit.
Two commenters state the FAA should distinguish in the AD between
major and minor pitting action. The FAA does not concur. The FAA has no
data to substantiate taking action for a minor versus a major pit other
than what is presented in Textron Lycoming MSB 505B. The survey to be
completed for the initial inspection of the crankshaft may assist the
FAA in determining a relationship between the number of pits and the
number of crankshafts cracked. This information may be used for future
rulemaking.
One commenter states that pitted crankshafts should be replaced at
overhaul. The FAA partially concurs. Textron Lycoming MSB 505B requires
that the crankshaft be replaced at overhaul if it is pitted. However,
from the data the FAA has received to date, many crankshafts are pitted
but not cracked. In addition, the FAA has received no substantiation
from Textron Lycoming or other sources to justify replacing a pitted
crankshaft at overhaul as long as it has received an MPI and has been
determined to have no cracks; and, when the engine is reinstalled in an
aircraft, an FPI is performed every 100 hours TIS to ensure that the
crankshaft is not cracked. The inspection survey will be utilized by
the FAA to determine the number of engines under repetitive FPI
inspections, the number of crankshafts that are found to be cracked,
whether another failure mechanism is contributing to the crankshaft
failures, and possible adjustment of the repetitive inspection
interval. The information obtained by this survey may lead to future
rulemaking.
After careful review of the available data, including the comments
noted above, 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 neither
increase the economic burden on any operator nor increase the scope of
the AD.
The total number of engines impacted worldwide is 16,357 (11,000,
160 hp, 320 series; and 5,357, 360 Series). The FAA estimates that 60%
of that number, 9,814 engines are installed on aircraft of U.S.
registry, and are affected by this AD. The FAA estimates that it will
take approximately 8 work hours per engine to accomplish the initial
visual inspection, and that the average labor rate is $60 per work
hour; therefore the estimated cost impact for the initial visual
inspections would be $4,710,720. The FAA also estimates, based on
information received from the UK CAA regarding the number of engines
undergoing repetitive inspections in the UK due to the UK CAA AD on the
same subject, that 12%, or 1,178, of the affected engines may contain
crankshafts that require FPI. The FAA estimates that each FPI will take
approximately 8 hours, and that operators with corroded crankshafts may
perform one FPI per year. The estimated cost for the repetitive FPI,
therefore, is $565,286 annually. Lastly, the FAA estimates that 5
crankshafts will require replacement per year due to cracks, and that
it will take 38 work hours per engine to replace cracked crankshafts.
Assuming that a replacement crankshaft will cost approximately $6,000
per engine, the estimated cost for replacement of 5 crankshafts will be
$41,400 annually. Therefore, the total estimated cost impact of this AD
is $5,317,406 for the first year, and $606,686 each year thereafter.
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 adding the following new
airworthiness directive:
98-02-08 Textron Lycoming: Amendment 39-10291. Docket 94-ANE-44.
Applicability: Textron Lycoming 320 series limited to 160
horsepower, and 360 series, four cylinder reciprocating engines with
fixed pitch propellers; except for the following installed in
helicopters or with solid crankshafts: HO-360 series, HIO-360
series, LHIO-360 series, VO-360 series, and IVO-360 series, and
Models O-320-B2C, O-360-J2A, AEIO-360-B4A, O-360-A4A, -A4G, -A4J, -
A4K, -A4M, and -C4F. In addition, engines with crankshafts
containing ``PID'' stamped on the outside diameter of the propeller
flange are exempt from the inspection requirements of this AD. The
affected 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 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 (g) 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.
[[Page 4157]]
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 engines shipped new from Textron Lycoming prior to and
including December 31, 1984, and that have never been overhauled, or
any engine remanufactured or overhauled and that has accumulated
1,000 hours or more time in service (TIS) since remanufacture or
overhaul, visually inspect the inside 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. 505B, dated December
1, 1997.
(1) If corrosion pits are found during this inspection, prior to
further flight, accomplish the following:
(i) If the crankshaft is installed in the engine such as during
an on-wing inspection, perform a fluorescent penetrant inspection
(FPI) in accordance with Textron Lycoming MSB No. 505B, dated
December 1, 1997.
(ii) If the crankshaft is removed from the engine at overhaul,
perform a magnetic particle inspection (MPI) in accordance with
Textron Lycoming MSB No. 505B, dated December 1, 1997.
(2) Within 48 hours after these inspections, report the finding
of the inspection in accordance with paragraph (e) of this AD.
(b) For engines shipped new from Textron Lycoming after December
31, 1984, and that have never been overhauled, or any engine
remanufactured or overhauled and that has accumulated less than
1,000 hours TIS since remanufacture or overhaul, visually inspect
the ID of the crankshaft for corrosion pits, at the earliest
occurrence of any event specified in subparagraph (3) of this
paragraph, and in accordance with Textron Lycoming MSB No. 505B,
dated December 1, 1997.
(1) If corrosion pits are found during this inspection, prior to
further flight perform an FPI or MPI in accordance with Textron
Lycoming MSB No. 505B, dated December 1, 1997.
(2) Within 48 hours after these inspections, report the finding
of the inspection in accordance with paragraph (e) of this AD.
(3) Visually inspect the ID of the crankshaft for corrosion pits
at the earliest of the following:
(i) The next engine overhaul or disassembly.
(ii) Within 10 years of the original shipping date or 6 months
from the effective date of this AD, whichever occurs later.
(iii) Within 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 or cracks are found on the
ID of the crankshaft during the initial visual inspection, perform a
visual 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. 505B,
dated December 1, 1997. If corrosion pits but no cracks are found on
the ID of the crankshaft during the initial visual inspection and
the ID does not exceed the maximum ID specified in Textron Lycoming
MSB No. 505B, dated December 1, 1997, repeat the FPI at intervals
not to exceed 100 hours TIS since last FPI or until a serviceable
crankshaft is installed in the engine.
(d) Prior to further flight, remove from service and replace
with a serviceable part any crankshaft found cracked during FPI or
MPI performed in accordance with Textron Lycoming MSB No. 505B,
dated December 1, 1997.
(e) After accomplishing the initial visual inspection and, if
necessary, the FPI or MPI, required by this AD, complete Appendix 1
of this AD and submit to the Manager, New York Aircraft
Certification Office, FAA, Engine and Propeller Directorate, 10
Fifth St., Valley Stream, NY 11581; fax (516) 568-2716. Reporting
requirements have been approved by the Office of Management and
Budget and assigned OMB control number 2120-0056.
Appendix 1
TEXTRON LYCOMING CRANKSHAFT INSPECTION SURVEY
AD Docket No. 94-ANE-44
Date of Inspection ____________________
Inspector's Information
Name-------------------------------------------------------------------
Address----------------------------------------------------------------
State ____________ Zip Code ____________
Telephone No.----------------------------------------------------------
Facsimile No.----------------------------------------------------------
Engine Model Number----------------------------------------------------
Engine Serial Number (S/N)---------------------------------------------
Date of Manufacture __________ (M/D/YR).
Total Time (TT) ________ hrs
Time Since Major Overhaul (SMOH) ________ hrs
Crankshaft Part Number (located on prop flange) ____________ S/N
____________
Aircraft Make and Model
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Frequency of Flights ____________ per month (average).
Duration ____________ hrs per Flight
How was aircraft being utilized? ________ Training, ________
Personal, ________ Banner Towing, ________ Glider Towing, ________
Agricultural, Other (please explain) ____________________
Propeller Make and Model
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Has the aircraft ever experienced a propeller strike during service?
________ Yes ________ No
Was propeller ever removed for servicing or overhaul? ________ Yes
________ No
If yes, describe reason for removal in detail?
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----------------------------------------------------------------------
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What was the condition of the crankshaft internal bore?
Corroded ____ Yes ____ No. If corroded, how many pits? ____ 1 to 5,
____ 6 to 10, ____ More than 10 ____________________
Was a crack found? ____ Yes ____ No. If crack was found, complete
the following:
________ Distance from crankshaft end (Inches) ________ Crack Length
(Inches)
Comments:
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(f) The application of Urethabond 104 to the inner bore of the
crankshaft and confirmed by stamping of the letters ``PID'' on the
outside diameter of the propeller flange in accordance with Textron
Lycoming MSB No. 530, dated December 1, 1997, constitutes
terminating action to the inspection requirements of this AD.
(g) 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 2: 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.
(h) 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.
(i) The actions required by this AD shall be done in accordance
with the following Textron Lycoming MSB:
------------------------------------------------------------------------
Document No. Pages Date
------------------------------------------------------------------------
505B............................... 1-5 Dec. 1, 1997.
Total pages...................... 5
530................................ 1-2 Dec. 1, 1997.
Total pages...................... 7
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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 St.,
Williamsport, PA 17701; telephone (717) 327-7080, fax (717) 327-
7100. 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.
(j) This amendment becomes effective on March 30, 1998.
Issued in Burlington, Massachusetts, on January 9, 1998.
James C. Jones,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 98-1705 Filed 1-27-98; 8:45 am]
BILLING CODE 4910-13-U