Airworthiness Directives; Textron Lycoming 235 Series, 290 Series, and Certain 320 and 360 Series Reciprocating Engines

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

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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

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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

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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]

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