Airworthiness Directives; Teledyne Continental Motors Models C75, C85, C90, C125, C145, O-200, O-300, and GO-300 Series Reciprocating Engines

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 92-ANE-32; Amendment 39-8843; AD 94-05-05]

Airworthiness Directives; Teledyne Continental Motors Models C75,

C85, C90, C125, C145, O-200, O-300, and GO-300 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 Teledyne Continental Motors (TCM) Models C75, C85, C90,

C125, C145, O-200, O-300, and GO-300 series reciprocating engines, that

requires inspection of the cylinder rocker shaft bosses for cracks, and

inspection of the cylinder rocker shaft for looseness and replacement,

if necessary, with a serviceable part. This amendment is prompted by

reports of cracked or improperly repaired cylinder rocker shaft bosses.

The actions specified by this AD are intended to prevent engine power

loss and engine failure.

EFFECTIVE DATE: May 2, 1994.

FOR FURTHER INFORMATION CONTACT: Jerry Robinette, Aerospace Engineer,

Atlanta Aircraft Certification Office, FAA, Small Airplane Directorate,

1669 Phoenix Parkway, Atlanta, GA 30349; telephone (404) 991-3810, fax

(404) 991-3606.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations to include an airworthiness directive (AD) that is

applicable to Teledyne Continental Motors (TCM) Models C75, C85, C90,

C125, C145, O-200, and O-300 series reciprocating engines was published

in the Federal Register on June 2, 1993 (58 FR 31348). That action

proposed to require fluorescent penetrant or etching inspections of the

cylinder rocker shaft bosses for cracks, and dimensional inspections of

the cylinder rocker shaft bosses for looseness, at the next overhaul,

in accordance with TCM Overhaul Manual Form X-30013, dated June 1982,

applicable to TCM Models C125, C145, and O-300 series engines; and TCM

Overhaul Manual Form X-30010, dated January 1984, applicable to TCM

Models C75, C85, C90, and O-200 series engines. If the cylinder rocker

shaft bosses are cracked, the cylinder must be replaced. Modified

cylinders must be further inspected for cracks that may have been

introduced during the repair process. Cylinders with loose rocker

shafts must be replaced with serviceable cylinders, or modified by

installing bushings.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

One commenter states that the AD should require compliance at the

next 100 hour or annual inspection, whichever occurs first. The

commenter further states that the AD should require visual inspection

for wear, broken bosses, or loose bushings at the earlier compliance

time because cylinders with cracked bosses or loose bushing will likely

fail before the cylinder requires overhaul. The FAA does not concur.

Service Difficulty Reports and engineering analysis do not indicate

that the shorter compliance time is necessary, and the comment did not

include any data as a basis for the shorter compliance time.

Furthermore, it is unlikely that a visual inspection without

disassembly could detect cracks or looseness in the cylinder rocker

shaft bosses.

The commenter further states that the TCM GO-300 series engines

should be included in the AD. Production of new cylinders has been

standardized by manufacturing the TCM GO-300 type cylinder only for use

on all C-75 through C-145, as well as the O-200 and O-300 series

engines. The commenter maintains that used GO-300 cylinder assemblies

may find their way onto other engines. The GO-300 shares nearly

identical valve train components with the other engines and is subject

to the same type of rocker boss wear and possible failures. The FAA

concurs. The GO-300 cylinders have been added to the applicability

paragraph of this AD.

The commenter further states that TCM Service Bulletin (SB) No.

M73-13 specifies a minimum edge thickness for the center rocker bosses

only. The commenter argues that this requirement for minimum thickness

should be redefined to be a minimum thickness anywhere on any boss

because many cylinders have bosses with adequate material on the edges

of the center bosses, but very little material between the edges. The

commenter concludes by stating that outer bosses, also require close

scrutiny for thickness, and if an outer boss fails, the center boss

will likely be overloaded and also fail. The FAA does not concur. The

center bosses are thinner by design and will therefore wear to the

limit sooner than the outer bosses. If the center bosses have the

correct edge to wall thickness, then the outer bosses will be correct

also.

The commenter further states that consideration should be given to

securing rocker boss repair bushings with a dowel pin to prevent

rotation after installation. The commenter argues that any lack of

concentricity between bushing ID and OD can severely overload bosses if

one or more bushings rotate after installation. The FAA does not

concur. If the repair is accomplished correctly, the bushing will be

pressed in and this press fit will prevent rotation.

The commenter further states that when performing inspections for

cracked bosses on cylinders that have been removed from the engine, dye

penetrant inspection should be allowed in addition to the fluorescent

penetrant inspection. The commenter maintains that dye penetrant

inspection is quite effective and reliable when properly performed and

is in widespread use by approved cylinder head repair facilities. The

FAA concurs. Dye penetrant inspection has been added to the AD as an

option for compliance. In addition, the FAA has added industry-accepted

procedures to the AD for performing dye penetrant, fluorescent

penetrant, and etching inspections in order to standardize the method

of inspection.

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 FAA estimates that 35,600 engines installed on aircraft of U.S.

registry would be affected by this AD, approximately 20,000 four-

cylinder engines and 15,600 six-cylinder engines. The FAA estimates

that it will take approximately one-half work hour per cylinder to

inspect or install the bushings, and that the average labor rate is $55

per work hour. Required parts will cost approximately $11 per cylinder.

Based on these figures, the cost impact of the AD for four-cylinder

engines is estimated to be $154 per engine, the cost impact of the AD

for six-cylinder engines is estimated to be $231 per engine, and the

total cost impact of the AD on U.S. operators is estimated to be

$6,683,600.

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 14 CFR part

39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

94-05-05 Teledyne Continental Motors: Amendment 39-8843. Docket 92-

ANE-32.

Applicability: Teledyne Continental Motors (TCM) Model C75, C85,

C90, C125, C145, O-200, O-300, and GO-300 series reciprocating

engines installed on but not limited to American Champion models

7BCM, 7CCM, 7DC, S7DC, S7CCM, 7EC, S7EC, 7FC, 7JC, and 7ECA; Cessna

Models 120, 140, 150, 170, 172, 172A-H, and 175; Luscombe Models 8E,

8F, and T-8F; Maule Models Bee Dee M-4, M-4, M-4C, M-4S, M-4T, M-4-

210, M-4-210C, M-4-210S, M-4-210T, and M-5-210C; Piper Models PA-18

and PA-19; Swift Models GC-1A and GC-1B; Univair (Erco) Models 415-

D, E, and G; Univair (Forney) Models F-1 and F-1A; Univair (Alon)

Model A-2 and Univair (Mooney) Model M-10 aircraft.

Compliance: Required as indicated, unless accomplished

previously.

To prevent engine power loss and engine failure, accomplish the

following:

(a) At the next cylinder or engine overhaul after the effective

date of this AD, inspect the cylinder rocker shaft bosses for cracks

using one of the following methods, and if cracked replace with a

serviceable cylinder:

Note: Certain cylinder cracks may be repaired by FAA-approved

repair stations specifically rated to do those repairs.

(1) Fluorescent penetrant inspection, as follows:

(i) The penetrant shall be a nontoxic, noncorrosive, highly

fluorescent liquid capable of penetrating fine discontinuities and,

for aluminum castings, conforming to Aerospace Material

Specification (AMS) 3156. If a darkened enclosure is not used for

examination, AMS 3157 penetrant shall be used.

(ii) The emulsifier shall be composed of suitable oil or oil-

like components together with such additives as are necessary to

provide a stable, nontoxic, noncorrosive, oil-miscible, oil-

emulsifying solution. Emulsifier shall not be used when AMS 3156 is

used.

(iii) The developer shall be a highly absorbent, nonfluorescent

and nontoxic powder, capable of being used dry or a similar powder

capable of being suspended in water. When the suspension is used,

the powder shall be thoroughly mixed with water to a concentration,

unless otherwise permitted, of not less than 0.2 lb per gallon and a

uniform distribution maintained by mechanical agitation.

(iv) The penetrant, the emulsifier (if used) and the developer

shall be checked as often as necessary to maintain proper control.

The penetrant shall be discarded if it shows a noticeable loss in

penetrating power or marked contamination or when wax begins to form

on the sides of the tank and dip basket.

(v) A darkness booth or a similar darkness area with a filtered

black light shall be provided. The black light shall be at least

equal to that produced by a 100 watt mercury vapor projection spot

lamp equipped with a filter to transmit wave lengths of between 3200

and 4000 Angstrom units and absorb substantially all visible light.

The intensity of the light at normal working distance shall be as

specified by the purchaser but in no case shall be lower than 580

micro-watts per square centimeter as measured with an appropriate

black light meter.

(vi) All parts shall be cleaned and dried in such a manner as to

leave them free from grease, oil, soaps, alkalies and other

substances which would interfere with inspection. Vapor degreasing

is generally suitable for this purpose.

(vii) Parts shall be immersed in the penetrant or shall be

sprayed or brushed with the penetrant and shall be allowed to remain

immersed in the penetrant or to stand for sufficient time to allow

satisfactory penetration into all discontinuities. This time shall,

unless otherwise specified, not be less than 5 minutes. The time for

immersion or standing will depend upon the character and fineness of

the discontinuities, the effectiveness of penetration increasing

with time. Parts may be resprayed or re-immersed after standing to

increase sensitivity and aid in removal of penetrant.

(viii) Parts shall be removed from the penetrant and cleaned

thoroughly using a medium which will remove penetrant from the

surface of parts; washing with water shall be used when the

penetrant is water washable or when an emulsifying agent is applied

to surfaces of parts to render the penetrant water washable. When

emulsifiers are used, the parts shall be dipped in the emulsifier

and removed slowly for draining or shall be sprayed with emulsifier

and drained. Unless otherwise specified, the combined dipping and

draining time shall be 1 to 5 minutes. When other than water

washable penetrants are used, the penetrant shall be removed with a

suitable cleaner or a suitable cleaner and lint-free cloths. During

cleaning, the parts may be viewed under a suitable black light to

ensure removal of the penetrant from the subrace of the part.

Excessive cleaning which would remove the penetrant from

discontinuities shall be avoided.

(ix) When a wet developer is used, the developer shall be

applied to the parts, immediately after washing, by immersing the

parts in the tank containing the water-suspended powder or by

spraying or flowing the suspension onto the parts. The suspension

shall be suitably agitated either during or immediately prior to

application to parts. Immersed parts shall be removed from the wet

developer; excess developer shall be allowed to drain off all parts.

Special care shall be taken to remove excess developer from pockets,

recesses, holes, threads, and corners so that the developer will not

mask indications.

(x) When a dry developer or no developer is used, the parts

shall be dried as thoroughly as possible by exposure to clean air.

Drying of parts may be accomplished by evaporation at room

temperature or by placing the parts in a circulating warm air oven

or in the air stream of a hot air dryer. Excessive drying time or

part temperatures higher than 80 deg.C (180 deg.F) should be avoided

to prevent evaporation of the penetrant.

(xi) When a dry developer is used, the developing powder shall

be applied uniformly over the areas of the parts to be inspected by

either dusting or powder-box immersion.

(xii) After sufficient time has been allowed to develop

indications, parts shall be examined under a black light.

Examination shall be made in a darkened enclosure unless AMS 3157

penetrant is used, in which case examination may be made under

normal shop lighting but shaded from direct sunlight.

(xiii) When greater sensitivity is desired, the parts may be

heated to 65 deg.-85 deg.C (150 deg.-185 deg.F) before immersion in

the penetrant and/or before black light examination. To prevent

evaporation, preheated parts shall remain fully immersed in the

penetrant until cooled.

(xiv) Parts shall be cleaned, as necessary, to remove penetrant

and developer.

(xv) Interpretation of the indications revealed by this

inspection procedure and final disposition of the parts shall be the

responsibility of only qualified personnel having experience with

fluorescent penetrant inspection.

(xvi) Parts having discontinuities (cracks) shall be rejected.

(2) Dye penetrant inspection, as follows:

Note: Military Specification MIL-I-6866 and American Society of

Testing Materials specifications ASTM E1417-93 and E165-9 contain

additional information on dye penetrant inspection processes.

(i) Preparation: clean and dry all parts in such a manner as to

leave the surfaces free from grease, oil, soaps, alkalies, and other

substances which would interfere with inspection. Vapor degreasing

is generally suitable for this purpose.

(ii) Penetrant Application Procedure: after preparation, spray

or brush the parts with the penetrant, and allow to stand for not

less than 5 minutes. The effectiveness of the penetrant increases if

left standing for a longer time, as the penetrant will reach finer

discontinuities.

(iii) Penetrant Cleaning: clean the parts thoroughly using a

medium which will remove penetrant from the surfaces of parts; wash

with water when the penetrant is water soluble. When other than

water soluble penetrants are used, the penetrant shall be removed

with a suitable cleaner. Avoid excessive cleaning which would remove

the penetrant from discontinuities.

(iv) Drying: dry the parts as thoroughly as possible. Drying of

parts may be accomplished by evaporation at room temperature or by

placing the parts in a circulating warm air oven or in the air

stream of a hot air dryer. Avoid excessive drying time or drying

temperatures above 75 deg.C (165 deg.F) to prevent excessive

evaporation of the penetrant. If heat is used for drying parts, cool

parts to approximately 50 deg.C (120 deg.F) before proceeding to the

developing procedure.

(v) Developing: apply the developer to the dry parts as lightly

and as evenly as possible, using as thin a coating of developer as

is possible. A translucent film is adequate. Mix wet developer by

agitation immediately prior to applying it. After applying the

developer, take care that no penetrant indication is disturbed or

obliterated in subsequent handling.

(vi) Examination: examine the developed penetrant indications in

accordance with the dye penetrant manufacturer's instructions.

Examine parts for indications of discontinuities open to the

surface.

(vii) Final cleaning: clean the parts following the inspection

to remove penetrant and developer.

Note 1: Caution: because of differences among penetrants, take

care to ensure that the final cleaner, the penetrant, the penetrant

remover, and the developer are suitable for use with each other.

Note 2: Caution: all penetrant materials should be kept as free

from moisture as possible.

Note 3: Caution: most penetrants, cleaning agents, and developer

suspensions are low flash point material; use caution to prevent

fires.

(3) Etching inspection, as follows:

(i) For TCM C75, C85, C90, and O-200 series engines, in

accordance with paragraph 13-7 of TCM Overhaul Manual Form X-30010,

dated January 1984.

(ii) For TCM C125, C145, O-300, and GO-300 series engines, in

accordance with paragraphs 5(b)(1), 5(b)(2), and 5(b)(3) of TCM

Overhaul Manual Form X-30013, dated June 1982.

(b) At the next cylinder or engine overhaul after the effective

date of this AD, dimensionally inspect cylinders for looseness of

the rocker shaft in accordance with page 22, paragraph 5, and Table

IX of TCM Overhaul Manual Form X-30013, dated June 1982, for TCM

Models C125, C145, O-300, and GO-300 series engines; page 75,

paragraph 13-6, and the dimensions table in paragraph 13-8 of TCM

Overhaul Manual Form X-30010, dated January 1984, for TCM Models

C75, C85, C90, and O-200 series engines; as applicable.

(1) Cylinders that do not exhibit dimensional looseness of the

rocker shaft beyond the limits specified in the applicable TCM

overhaul manual may be returned to service.

(2) For cylinders that exhibit dimensional looseness of the

rocker shaft, beyond the limits specified in the applicable TCM

overhaul manual, accomplish the following:

(i) Replace with a serviceable cylinder; or

(ii) Install bushings in accordance with the instructions on

page 27 of TCM Overhaul Manual, Form X-30013, dated June 1982, for

TCM Models C125, C145, O-300, and GO-300 series engines; or the

instructions on page 85 of TCM Overhaul Manual Form X-30010, dated

January 1984, for TCM Models C75, C85, C90, and O-200 series

engines; as applicable.

(iii) After repairing a cylinder perform an additional

inspection of the cylinder rocker shaft bosses for cracks using

fluorescent penetrant, dye penetrant, or etching methods, and

replace, if necessary, with a serviceable cylinder.

(c) Thereafter, at each subsequent cylinder or engine overhaul,

reinspect cylinder rocker bosses and rocker shafts in accordance

with paragraphs (a) and (b) of this AD.

(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, Atlanta 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, Atlanta 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 Atlanta Aircraft Certification

Office.

(e) Special flight permits may be issued in accordance with FAR

21.197 and 21.199 to operate the airplane to a location where the

requirements of this AD can be accomplished.

(f) This amendment becomes effective on May 2, 1994.

Issued in Burlington, Massachusetts, on February 18, 1994.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification

Service.

[FR Doc. 94-4837 Filed 3-2-94; 8:45 am]

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