[Federal Register Volume 60, Number 2 (Wednesday, January 4, 1995)]
[Proposed Rules]
[Pages 389-393]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-62]



[[Page 389]]

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-NM-114-AD]


Airworthiness Directives; McDonnell Douglas Model DC-10 Series 
Airplanes and Model KC-10A (Military) Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain McDonnell Douglas Model 
DC-10 series airplanes and Model KC-10A (military) airplanes. This 
proposal would require various modifications of the flight controls, 
hydraulic power systems, and landing gear. This proposal is prompted by 
a recommendation by the Systems Review Task Force (SRTF) for 
accomplishment of certain modifications that will enhance the 
controllability of these airplanes in the unlikely event of 
catastrophic damage to all hydraulics systems. The actions specified by 
the proposed AD are intended to ensure airplane survivability in the 
event of damage to fully powered flight control systems.

DATES: Comments must be received by March 1, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-114-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach, 
California 90801-1771, Attention: Business Unit Manager, Technical 
Administrative Support, Dept. L51, Mail Code 2-98. This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount 
Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Mauricio J. Kuttler, Aerospace 
Engineer, Systems and Equipment Branch, ANM-131L, FAA, Transport 
Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 
Paramount Boulevard, Lakewood, California 90712; telephone (310) 627-
5355; fax (310) 627-5210.

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 shall 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 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-NM-114-AD.'' 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, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 94-NM-114-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion-

    In July 1989, a McDonnell Douglas Model DC-10-30 series airplane 
was involved in an accident in Sioux City, Iowa, resulting in the 
deaths of 110 passengers and one crewmember. The National 
Transportation Safety Board (NTSB) identified the catastrophic 
disintegration of the stage 1 fan disk of one of the engines as a 
probable cause of the accident. The resulting debris damaged the 
hydraulic systems that power the flight controls, resulting in the loss 
of virtually all control capability.-
    Following the accident, the Administrator of the Federal Aviation 
Administration convened a Systems Review Task Force (SRTF) to 
investigate means for enhancing airplane survivability following damage 
to fully powered flight control systems. The SRTF formed working groups 
to perform these investigations for specific airplane models to 
determine what actions could be effective in protecting other transport 
category airplanes with powered flight control systems from similar 
engine or systems failures.-
    The SRTF working group assigned to review Model DC-10 series 
airplanes completed its review of the Model DC-10 design, including 
existing service bulletins, and issued a report recommending 
accomplishment of certain modifications described in 12 Model DC-10 
service bulletins. A copy of the report is contained in the Rules 
Docket for this AD action.

Explanation of Relevant Service Documents-

    The FAA has reviewed and approved the 12 McDonnell Douglas DC-10 
Service Bulletins recommended for accomplishment by the SRTF working 
group. Accomplishment of the modifications specified in these service 
bulletins will enhance the controllability of the airplane in the 
unlikely event of catastrophic damage to all three hydraulic systems in 
the tail area of the airplane.
    Seven of the 12 service bulletins discussed previously describe 
procedures for various modifications of the flight controls:-
    1. McDonnell Douglas DC-10 Service Bulletin 27-71, Revision 1, 
dated February 14, 1973, was issued in response to reports of failures 
of the piping of the hydraulic system of the horizontal stabilizer on 
Model DC-10 series airplanes that had accumulated as few as 70 flight 
hours. The failures were attributed to rapid release of the trim 
control handles of the stabilizer, which resulted in pressure surges 
that were abnormally high in the hydraulic system of the stabilizer. 
Continued high pressure surges and externally induced vibrations could 
result in fatigue failure of the hydraulic piping. These conditions, if 
not corrected, could result in the loss of fluid, which could render 
the affected system inoperative.-
    The service bulletin describes procedures for installation of surge 
damper assemblies and new piping assemblies in hydraulic systems 1 and 
3 of the horizontal stabilizer. Installation of the dampers and piping 
will ensure that high pressure surges are absorbed and will prevent 
pipe failures.-
    2. McDonnell Douglas DC-10 Service Bulletin 27-120, dated February 
10, 1975, describes procedures for modification and reidentification of 
the trim hydraulic motor assembly of the [[Page 390]] horizontal 
stabilizer. Accomplishment of the modification will minimize the 
possibility of fatigue failure of the motor case screws and shuttle 
valve screws. (The service bulletin references Sperry Rand Corporation, 
Vickers Division, Service Bulletin 390017-27-2, dated December 2, 1974, 
as an additional source of service information.) Failure of the motor 
case screws and/or failure of the shuttle valve screws, if not 
corrected, could result in loss of hydraulic system fluid. Failure of 
two shuttle valve screws could cause the shuttle valve to separate from 
the trim motor.-
    3. McDonnell Douglas DC-10 Service Bulletin 27-152, dated August 9, 
1976, was issued in response to a report of inoperative horizontal 
stabilizer trim due to disengagement of the torsional coupling of the 
drive system on Model DC-10 series airplanes that had accumulated 
approximately 4,100 flight hours. In addition, during fleet 
inspections, loose retaining nuts and locking clips were found on these 
airplanes; the torsional nut did not engage adequately to provide 
locking action. The inoperative horizontal stabilizer trim was 
attributed to failure of the locking clip to prevent the retaining nut 
of the torsional coupling from rotating and becoming loose. This 
condition could result in the retaining nut becoming loose and allowing 
disengagement of the torsional coupling. This condition, if not 
corrected, could result in the loss of horizontal stabilizer trim 
capability.
    The service bulletin describes procedures for replacing the 
existing locking clip on the torsional coupling of the horizontal 
stabilizer with a new nut retainer of an improved design. 
Accomplishment of this modification will minimize the possibility of 
the torsional nut becoming loose.-
    4. McDonnell Douglas DC-10 Service Bulletin 27-181, Revision 1, 
dated May 28, 1981, was issued in response to reports of failure of the 
differential drive shear pin in the horizontal stabilizer drive system. 
These failures occurred during takeoff climb on Model DC-10 series 
airplanes that had accumulated between 4 and 4,201 flight hours. 
Investigation revealed that these failures were caused by bending 
fatigue of the shear pin due to a loose fit. Failure of the shear pin 
could result in an inoperative horizontal stabilizer drive system. This 
condition, if not corrected, could result in reduced controllability of 
the airplane.-
    The service bulletin describes procedures for installation of a 
modified chain drive unit on the horizontal stabilizer. The new unit 
incorporates a larger shear pin with a single shear point having a 
larger diameter with less constraint. Accomplishment of this 
modification will increase the reliability of the drive assembly.-
    5. McDonnell Douglas DC-10 Service Bulletin 27-201, dated December 
30, 1985, was issued in response to a report of in-flight loss of 
hydraulic systems 1 and 2 shortly after takeoff of a Model DC-10 series 
airplane. Investigation revealed that the loss of hydraulic systems was 
caused by blowout of the number 6 tire after gear retraction. The 
blowout deflected the keel web structure, which ruptured hydraulic 
pipes to the flap lock valves and caused rapid loss of fluid. This 
condition, if not corrected, could result in loss of operation of the 
hydraulic system.-
    The service bulletin describes procedures for replacement of the 
hydraulic pipe assemblies of the flap lock valve with new pipe 
assemblies having increased flexibility and strength. Installation of 
these pipe assemblies will minimize the possibility of rupture of the 
pipe assemblies during events such as those described previously.-
    6. McDonnell Douglas DC-10 Service Bulletin 27-208, dated September 
5, 1989, was issued in response to reports of cracking of the end caps 
of the trim control valve of the horizontal stabilizer on Model DC-10 
series airplanes that had accumulated between 9,800 and 16,000 flight 
hours. Investigation revealed that fatigue cracking initiated from 
inside the radius of the end cap. Such fatigue cracking, if not 
corrected, could result in loss of hydraulic fluid and eventual 
shutdown of the hydraulic system.-
    The service bulletin describes procedures for replacement of eight 
end caps of the trim control valve of the horizontal stabilizer with 
new end caps having a larger inside radius. Replacement of the end caps 
will minimize the possibility of cracking of the end caps.-
    7. McDonnell Douglas DC-10 Service Bulletin 27-209, dated October 
20, 1989, was issued in response to reports of failure of the chain 
drive fuse of the horizontal stabilizer on Model DC-10 series airplanes 
that had accumulated between 4,000 and 18,000 flight hours. 
Investigation revealed that a fuse pin within the chain drive unit had 
sheared due to loose nuts on the shaft assembly. These conditions, if 
not corrected, could result in the horizontal stabilizer drive system 
becoming inoperative.-
    The service bulletin describes procedures for inspecting the nuts 
on the shaft assembly for looseness, proper orientation, excess 
backlash, and engagement of the washer locking tab; and replacing the 
fuse pin, adjusting backlash, and properly positioning and tightening 
the nuts, if necessary. Replacing the fuse pin and tightening the nuts 
will minimize the possibility of failure of the chain drive fuse of the 
horizontal stabilizer.-
    Two of the 12 service bulletins describe procedures for 
modifications of certain hydraulic power systems:-
    8. McDonnell Douglas DC-10 Service Bulletin 29-109, Revision 1, 
dated September 22, 1978, was issued in response to reports of rapid 
rise in temperature in hydraulic system 3 subsequent to the loss of 
hydraulic fluid in hydraulic system 1 or 2. Investigation revealed that 
a shutoff valve on the reversible motor pump may fail on one side of 
the reversible motor pump and that failure may go undetected. This 
failure poses a problem if a failure occurs in the opposite hydraulic 
system that causes total loss of that system's fluid. If a valve fails 
in the open position on one side and fluid is lost from the opposite 
hydraulic system, the reversible motor pump will rotate at maximum rpm 
(limited by the flow control). This condition, if not corrected, could 
result in a rise in temperature in the opposite hydraulic system, which 
may necessitate limited use of the engine-drive pumps on that hydraulic 
system.-
    The service bulletin describes procedures for installation of an 
indication system that will allow the flight crew to immediately detect 
an inoperative shutoff valve on the reversible motor pump. The 
installation of the indication system involves installing two pressure 
switches on the reversible motor pumps; installing a ground stud, two 
relays, and receptacles on the center compartment electrical rack; 
replacing the 6-post terminal strip in the wheel well of the right main 
landing gear with an 8-post terminal strip; installing an annunciator 
legend on the flight engineer's annunciator panel; installing a circuit 
breaker and replacing the nameplate on the flight engineer's circuit 
breaker panel; revising the failure indication wiring on the constant 
speed drive; and installing indication wiring and associated clamps and 
brackets on the reversible motor pump.-
    9. McDonnell Douglas DC-10 Service Bulletin 29-125, Revision 2, 
dated October 23, 1987, was issued in response to reports of complete 
loss of fluid from the number 3 hydraulic system. The fluid loss was 
caused by a ruptured hi-pressure switch on the hydraulic case drain. 
This condition, if [[Page 391]] not corrected, could result in the loss 
of function of the hydraulic system.
    The service bulletin describes procedures for modification of the 
main hydraulic power system. The modification involves replacing the 
hi-pressure switches on the hydraulic case drain on engine numbers 1, 
2, and 3 with plugs; removing one relay and one receptacle on the aft 
relay panel of the equipment rack; replacing the existing legend in 
position 8 on the flight engineer's annunciator panel with a blank 
legend; and revising the wiring for indicating the aircraft hydraulic 
temperature and pressure. Accomplishment of this modification will 
minimize the possibility of loss of hydraulic fluid.-
    Three of the 12 service bulletins describe procedures for 
modifications of the landing gear:-
    10. McDonnell Douglas DC-10 Service Bulletin 32-134, dated March 
22, 1977, was issued in response to reports of damage to the electrical 
and hydraulic installations of the aft antiskid manifold on the main 
landing gear. The damage resulted from blown tire fragments and debris, 
which rendered the antiskid system inoperative and, in one case, 
ruptured a hydraulic pipe. Failure of the pipe, if not corrected, could 
cause hydraulic system numbers 1 or 3 to become inoperative due to the 
loss of hydraulic fluid.-
    The service bulletin describes procedures for modification of the 
aft antiskid manifold on the left and right main landing gear. The 
modification entails installing a protective shield and associated 
brackets on the aft antiskid manifold. Accomplishment of this 
modification will minimize the possibility of damage to the aft 
antiskid manifold.-
    11. McDonnell Douglas DC-10 Service Bulletin 32-143, dated August 
8, 1978, was issued in response to reports of damage to the brake 
piping that is routed between the antiskid manifolds and the swivel 
glands of the main landing gear. This damage occurred as a result of 
the impact of debris following failure of a tire on the main landing 
gear. A ruptured antiskid return pipe could result in loss of fluid 
from the affected antiskid system during application of the brakes. A 
single failure of a pressure pipe will limit brake performance on a 
single system. Failure of brake pressure pipes in both systems, if not 
corrected, could result in complete loss of braking capability.-
    The service bulletin describes procedures for installation of 
protective shields over the brake and the antiskid piping located on 
the aft side of the left and right main landing gear. Accomplishment of 
this modification will minimize the possibility of brake pressure and 
damage to the antiskid return piping caused by failure of a tire on the 
main landing gear.-
    12. McDonnell Douglas DC-10 Service Bulletin 32-157, Revision 1, 
dated October 29, 1980, was issued in response to a report of damage to 
a support bracket on the aileron trim cable and to a flight control 
mixer in the wheel well of the centerline landing gear. Investigation 
revealed that the damage was caused by the impact of a tire tread that 
was thrown into the open area created by the aft doors on the 
centerline landing gear when the landing gear is in the down position. 
This condition, if not corrected, could result in damage to components 
located in the wheel well of that landing gear.-
    The service bulletin describes procedures for installing a doubler 
on the web assembly between the wheel wells of the center landing gear 
and the right main landing gear; installing a fiberglass deflector 
assembly on the shock strut of the centerline landing gear; replacing 
the pressure gage manifold of the shock strut; and installing an 
instruction plate and adding precaution instruction markings in the 
wheel well of the right main landing gear and on the forward door of 
the center landing gear. Accomplishment of this modification will 
minimize the possibility of damage to components in the wheel well of 
the centerline landing gear caused by a thrown tire tread or other 
debris.

Explanation of the Proposed Rule-

    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 various modifications of the flight controls, 
hydraulic power systems, and landing gear. The actions would be 
required to be accomplished in accordance with the McDonnell Douglas 
service bulletins described previously.-
    The FAA is continuing to review the recommendations of the SRTF 
working group for these airplanes and may consider further rulemaking 
based on those recommendations.-
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been included in this notice to clarify this requirement.

Cost Impact-

    There are approximately 427 Model DC-10 series airplanes and Model 
KC-10A (military) airplanes of the affected design in the worldwide 
fleet. The FAA estimates that 254 airplanes of U.S. registry would be 
affected by this proposed AD.-
    Approximate work hours to accomplish the proposed actions and costs 
for required parts are listed in the following table. The average labor 
rate is $60 per work hour.

------------------------------------------------------------------------
                                       Estimated  Parts cost  Total cost
        Service bulletin No.-             work        per         per   
                                         hours-    airplane    airplane 
------------------------------------------------------------------------
27-71................................         5        (\1\)     $300.00
27-120...............................         3       $68.00      248.00
27-152...............................         1       278.00      338.00
27-181...............................         5       431.00      731.00
27-201...............................        10     7,943.00    8,543.00
27-208...............................         5     3,704.00    4,004.00
27-209...............................         9          N/A      540.00
29-109...............................       101       713.00    6,773.00
29-125...............................         4       498.00      738.00
32-134...............................         3     2,034.00    2,214.00
32-143...............................         3       649.00      829.00
32-157...............................         6    46,463.00   46,823.00
------------------------------------------------------------------------
\1\Required parts would be supplied by the manufacturer at no cost to   
  operators.-                                                           

    Based on these figures, the total cost impact of the proposed AD on 
U.S. operators is estimated to be $18,308,574, or $72,081 per 
airplane.-
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.-
    The number of required work hours, as indicated above, is presented 
as if the accomplishment of the actions proposed in this AD were to be 
conducted as ``stand alone'' actions. However, the 24-month compliance 
time specified in paragraph (a) of this proposed AD should allow ample 
time for the actions to be accomplished coincidentally with scheduled 
major airplane inspection and maintenance activities, thereby 
minimizing the costs associated with special airplane scheduling.- 
[[Page 392]] 
    Further, the FAA recognizes that the obligation to maintain 
aircraft in an airworthy condition is vital, but sometimes expensive. 
Because AD's require specific actions to address specific unsafe 
conditions, they appear to impose costs that would not otherwise be 
borne by operators. However, because of the general obligation of 
operators to maintain aircraft in an airworthy condition, this 
appearance is deceptive. Attributing those costs solely to the issuance 
of this AD is unrealistic because, in the interest of maintaining safe 
aircraft, most prudent operators would accomplish the required actions 
even if they were not required to do so by the AD. -
    A full cost-benefit analysis has not been accomplished for this 
proposed AD. As a matter of law, in order to be airworthy, an aircraft 
must conform to its type design and be in a condition for safe 
operation. The type design is approved only after the FAA makes a 
determination that it complies with all applicable airworthiness 
requirements. In adopting and maintaining those requirements, the FAA 
has already made the determination that they establish a level of 
safety that is cost-beneficial. When the FAA, as in this proposed AD, 
makes a finding of an unsafe condition, this means that the original 
cost-beneficial level of safety is no longer being achieved and that 
the proposed actions are necessary to restore that level of safety. 
Because this level of safety has already been determined to be cost-
beneficial, a full cost-benefit analysis for this proposed AD would be 
redundant and unnecessary.

Regulatory Impact

    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 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:

    McDonnell Douglas: Docket 94-NM-114-AD.-
    Applicability: Model DC-10-10, -10F, -15, -30, -30F, -40, and -
40F series airplanes and Model KC-10A (military) airplanes; as 
listed in the following McDonnell Douglas DC-10 service bulletins; 
certificated in any category:-

------------------------------------------------------------------------
 Service bulletin No. -      Revision level -          Date issued-     
------------------------------------------------------------------------
27-71-.................  1 -....................  February 14, 1973.-   
27-120-................  Original-..............  February 10, 1975.-   
27-152-................  Original-..............  August 9, 1976.-      
27-181-................  1 -....................  May 28, 1981.-        
27-201-................  Original-..............  December 30, 1985.-   
27-208-................  Original-..............  September 5, 1989.-   
27-209-................  Original-..............  October 20, 1989.-    
29-109-................  1-.....................  September 22, 1978.-  
29-125-................  2-.....................  October 23, 1987.-    
32-134-................  Original-..............  March 22, 1977.-      
32-143-................  Original-..............  August 8, 1978.-      
32-157-................  1-.....................  October 29, 1980.-    
------------------------------------------------------------------------

    Note 1: This AD applies to each airplane 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 airplanes 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 (b) to request approval from the 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 airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously. -
    To ensure airplane survivability in the event of damage to fully 
powered flight control systems, accomplish the following:-
    (a) Within 24 months after the effective date of this AD, modify 
the flight controls, hydraulic power systems, and landing gear in 
accordance with paragraphs (a)(1) through (a)(12) of this AD, as 
applicable.-
    (1) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 27-71, Revision 1, dated February 14, 1973: Install surge 
damper assemblies and new piping assemblies in hydraulic systems 1 
and 3 of the horizontal stabilizer in accordance with the service 
bulletin. As of the effective date of this AD, no person shall 
install a pipe assembly, part number AJK7004-641, -642, -643, -644, 
-645, -646, -647, or -648 on any airplane. As of the effective date 
of this AD, no person shall install a valve assembly, part number 
AJG7041-5515 or -5517, on any airplane unless that assembly has been 
modified in accordance with the service bulletin.-
    (2) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 27-120, dated February 10, 1975: Modify and reidentify the 
trim hydraulic motor assembly of the horizontal stabilizer in 
accordance with the service bulletin.

    Note 2: The McDonnell Douglas service bulletin references Sperry 
Rand Corporation, Vickers Division, Service Bulletin 390017-27-2, 
dated December 2, 1974, as an additional source of service 
information.

    (3) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 27-152, dated August 9, 1976: Replace the existing 
retaining nut locking clip on the torsional coupling of the 
horizontal stabilizer with a new retaining nut locking clip in 
accordance with the service bulletin. As of the effective date of 
this AD, no person shall install a locking clip or nut retainer, 
part number AJH7259-1, on any airplane.-
    (4) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 27-181, Revision 1, dated May 28, 1981: Install a modified 
chain drive unit on the horizontal stabilizer in accordance with the 
service bulletin. As of the effective date of this AD, no person 
shall install a chain drive unit assembly, part number AJH7337-1 or 
AJH7337-501; pin, part number AJH7343-1; housing assembly, part 
number AJH7345-1; shaft, part number AJH7075-1 or -501; or decal, 
part number AJH7347-1; on any airplane.-
    (5) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 27-201, dated December 30, 1985: Replace the hydraulic pipe 
assemblies of the flap lock valve with new pipe assemblies in 
accordance with the service bulletin. As of the effective date of 
this AD, no person shall install a pipe assembly, part number 
AYK7002-876, -877, -878, -879, -880, and -881; AYK7136-1; and 
AYK7137-1; on any airplane.- [[Page 393]] 
    (6) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 27-208, dated September 5, 1989: Replace eight end caps of 
the trim control valve of the horizontal stabilizer with new end 
caps having a larger inside radius, in accordance with the service 
bulletin. As of the effective date of this AD, no person shall 
install an end cap, part number AJG7020-503; or valve assembly, part 
number AJG7041-5535, -5533, -5531, -5529, -5527, -5525, -5523, -
5521, -5519, -5517, -5515, -5513, -5511, -5509, -5507, -5505, -5503, 
-5501, or -5001; on any airplane.-
    (7) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 27-209, dated October 20, 1989: Inspect the nuts on the 
shaft assembly for looseness, proper orientation, excess backlash, 
and engagement of the washer locking tab, in accordance with the 
service bulletin. As of the effective date of this AD, no person 
shall install a drive assembly, part number AJH7337-505, on any 
airplane unless that assembly has been modified in accordance with 
the service bulletin.-
    (i) If no discrepancy is found, no further action is required by 
this paragraph.-
    (ii) If any discrepancy is found, prior to further flight, 
replace the fuse pin, adjust backlash, and properly position and 
tighten the nuts in accordance with the service bulletin.-
    (8) For airplanes listed in McDonnell Douglas Service Bulletin 
29-109, Revision 1, dated September 22, 1978: Install an indication 
system on the reversible motor pump in accordance with the service 
bulletin. As of the effective date of this AD, no person shall 
install a nameplate, part number ABN7191-1124, -1125, -1126, -872, -
873, -874, -878, or -1084; a support, part number 2394536-509; or a 
plate, part number 2710497-1-6; on any airplane.-
    (9) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 29-125, Revision 2, dated October 23, 1987: Modify the main 
hydraulic power system in accordance with the service bulletin. As 
of the effective date of this AD, no person shall install an 
annunciator panel, part number 102200-268, or -274, on any airplane 
unless that panel has been modified in accordance with the service 
bulletin.-
    (10) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 32-134, dated March 22, 1977: Modify the aft antiskid 
manifold on the left and right main landing gear in accordance with 
the service bulletin. As of the effective date of this AD, no person 
shall install a bracket, part number ARG7291-1, ARG7291-501,ARG7485-
501, or ARG7485-502 on any airplane. As of the effective date of 
this AD, no person shall install a main landing gear assembly, part 
number ARG7393-(Any Configuration), on any airplane unless that 
assembly has been modified in accordance with the service bulletin.-
    (11) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 32-143, dated August 8, 1978: Install protective shields 
over the brake and antiskid piping located on the aft side of the 
left and right main landing gear in accordance with the service 
bulletin. As of the effective date of this AD, no person shall 
install a support, part number ARG7551-1 or ARG7552-1, or bracket, 
part number AEP8009-25, on any airplane. As of the effective date of 
this AD, no person shall install a main landing gear assembly, part 
number ARG7393-(Any Configuration), on any airplane unless that 
assembly has been modified in accordance with the service bulletin.-
    (12) For airplanes listed in McDonnell Douglas DC-10 Service 
Bulletin 32-157, Revision 1, dated October 29, 1980: Install a 
doubler on the web assembly between the wheel wells of the center 
landing gear and the right main landing gear; install a fiberglass 
deflector assembly on the shock strut of the centerline landing 
gear; replace the pressure gage manifold of the shock strut; and 
install an instruction plate and adding precaution instruction 
markings in the wheel well of the right main landing gear and on the 
forward door of the center landing gear in accordance with the 
service bulletin. As of the effective date of this AD, no person 
shall install a manifold, part number AYK7162-501, on any airplane.-
    (b) 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, Los Angeles Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Los Angeles ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (c) 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 airplane to a location where 
the requirements of this AD can be accomplished. Issued in Renton, 
Washington, on December 28, 1994.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-62 Filed 1-3-95; 8:45 am]
BILLING CODE 4910-13-U