[Federal Register Volume 59, Number 42 (Thursday, March 3, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-4837]
[[Page Unknown]]
[Federal Register: March 3, 1994]
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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]
BILLING CODE 4910-13-P