[Federal Register Volume 63, Number 59 (Friday, March 27, 1998)]
[Proposed Rules]
[Pages 14851-14853]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8099]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-55-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-10 and MD-11 
Series Airplanes, and KC-10 (Military) Series Airplanes

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 certain McDonnell Douglas Model 
DC-10 and MD-11 series airplanes, and KC-10 (military) series 
airplanes. This proposal would require a one-time inspection for 
blockage of the lubrication holes on the forward trunnion spacer 
assembly, and a one-time inspection of the forward trunnion bolt on the 
left and right main landing gear (MLG) to detect discrepancies; and 
repair, if necessary. This proposal is prompted by reports of blockage 
by opposing bushings of the lubrication holes on the forward trunnion 
spacer assembly, and reports of flaking, galling, and corrosion of the 
forward trunnion bolt. The actions specified by the proposed AD are 
intended to detect and correct such flaking, galling, and corrosion of 
the forward trunnion bolt, which could result in premature failure of 
the forward trunnion bolt and could lead to separation of the MLG from 
the wing during takeoff and landing.

DATES: Comments must be received by May 11, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-55-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 The Boeing Company, Douglas Products Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Technical 
Publications Business Administration, Dept. C1-L51 (2-60). 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: Ron Atmur, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (562) 627-5224; fax (562) 
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

[[Page 14852]]

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 98-NM-55-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-114, Attention: Rules 
Docket No. 98-NM-55-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports from two operators indicating that, in 
five instances on McDonnell Douglas Model MD-11 in-service airplanes, 
the lubrication holes on the forward trunnion spacer assembly on the 
left and right main landing gear (MLG) were blocked by opposing 
bushings, and that the forward trunnion bolt on the left and right MLG 
was flaking, galling, and corroding. Investigations have revealed that 
the forward trunnion spacer assemblies were manufactured in a way that 
could block the lubrication holes. If the lubrication holes are 
blocked, lubricant cannot migrate to the forward trunnion bolt. Without 
lubrication, the chrome surface of the forward trunnion bolt may flake 
and gall and the grooves of the bolt may corrode. This condition, if 
not corrected, could result in premature failure of the forward 
trunnion bolt, which could lead to separation of the MLG from the wing 
during takeoff and landing.
    Although the forward trunnion spacer assemblies were installed 
during production on Model MD-11 series airplanes, the spacer 
assemblies may have been used as spare parts on Model DC-10 series 
airplanes and KC-10 (military) series airplanes.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin MD11-32-074, dated December 15, 1997, and McDonnell Douglas 
Service Bulletin DC10-32-248, dated December 17, 1997, which describe 
procedures for a one-time visual inspection of the lubrication holes on 
the forward trunnion spacer assembly on the left and right MLG for 
blockage by opposing bushings; a one-time visual inspection of the 
forward trunnion bolt on the left and right MLG for chrome flaking, 
galling, and corrosion in the grooves; and repair, if necessary. 
Accomplishment of the actions specified in these service bulletins is 
intended to adequately address the identified unsafe condition.

Explanation of Requirements of 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 accomplishment of the actions specified in 
the service bulletins described previously, except as discussed below.

Differences Between the Proposed Rule and the Relevant Service 
Information

    Operators should note that, although the service bulletins 
recommend accomplishing the visual inspections at the earliest 
practical maintenance period or within 24 months, the FAA has 
determined that an interval of 24 months would not address the 
identified unsafe condition in a timely manner. In developing 
appropriate compliance times for this AD, the FAA considered not only 
the manufacturer's recommendation, but the degree of urgency associated 
with addressing the subject unsafe condition, the average utilization 
of the affected fleet, and the time necessary to perform the 
inspections (less than one work hour). In light of all of these 
factors, the FAA finds an 18-month compliance time for Model DC-10 
series airplanes and Model KC-10 (military) series airplanes, and a 15-
month compliance time for Model MD-11 series airplanes for initiating 
the required actions to be warranted. These compliance times represent 
appropriate intervals of time allowable for affected airplanes to 
continue to operate without compromising safety.

Cost Impact

    There are approximately 522 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 326 McDonnell Douglas Model DC-
10 and MD-11 series airplanes and KC-10 (military) series airplanes of 
U.S. registry would be affected by this proposed AD.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed inspection, at an average labor rate of $60 per work hour. 
Based on this figure, the cost impact of the proposed AD on U.S. 
operators is estimated to be $19,560, or $60 per airplane.
    The 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.

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:

[[Page 14853]]

PART 39--AIRWORTHINESS DIRECTIVES

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

    Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:
McDonnell Douglas:  Docket 98-NM-55-AD.

    Applicability: Model DC-10 and MD-11 series airplanes, and KC-10 
(military) series airplanes; as listed in McDonnell Douglas Service 
Bulletin DC10-32-248, dated December 17, 1997, and in McDonnell 
Douglas Service Bulletin MD11-32-074, dated December 15, 1997; 
certificated in any category.
    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 request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct flaking, galling, and corrosion of the 
forward trunnion bolt as a result of installation of a suspected 
unapproved part (SUP), and consequent premature failure of the 
forward trunnion bolt and separation of the main landing gear (MLG) 
from the wing during takeoff and landing, accomplish the following:
    (a) For airplanes listed in McDonnell Douglas Service Bulletin 
MD11-32-074, dated December 15, 1997: Within 15 months after the 
effective date of this AD, perform a one-time visual inspection of 
the lubrication holes on the forward trunnion spacer assembly on the 
MLG for blockage by opposing bushings, and perform a one-time visual 
inspection of the forward trunnion bolt on the left and right MLG 
for chrome flaking, galling, and corrosion in the grooves; in 
accordance with the service bulletin.
    (1) Condition 1. If the lubrication holes on the forward 
trunnion spacer assembly are not blocked by opposing bushings, and 
the forward trunnion bolt does not reveal chrome flaking or galling, 
and exhibits no corrosion in the grooves, no further work is 
required by this AD.
    (2) Condition 2. If the lubrication holes on the forward 
trunnion spacer assembly are blocked by opposing bushings, and the 
forward trunnion bolt does not reveal chrome flaking or galling, and 
exhibits no corrosion in the grooves: Prior to further flight, 
replace the forward trunnion spacer assembly with a new part in 
accordance with the service bulletin.
    (3) Condition 3. If the lubrication holes on the forward 
trunnion spacer assembly are blocked by opposing bushings, and the 
forward trunnion bolt reveals chrome flaking, galling, or corrosion 
in the grooves, accomplish either paragraph (a)(3)(i) or (a)(3)(ii) 
of this AD:
    (i) Option 1. Prior to further flight, replace the forward 
trunnion spacer assembly with a new part, and replace the forward 
trunnion bolt with a new part in accordance with the service 
bulletin. Or
    (ii) Option 2. Prior to further flight, replace the forward 
trunnion spacer assembly with a new part, and rework the forward 
trunnion bolt in accordance with the service bulletin.
    (b) For airplanes listed in McDonnell Douglas Service Bulletin 
DC10-32-248, dated December 17, 1997: Within 18 months after the 
effective date of this AD, perform a one-time visual inspection of 
the lubrication holes on the forward trunnion spacer assembly on the 
MLG for blockage by opposing bushings, and perform a one-time visual 
inspection of the forward trunnion bolt on the left and right MLG 
for chrome flaking, galling, and corrosion in the grooves; in 
accordance with the service bulletin.
    (1) Condition 1. If the lubrication holes on the forward 
trunnion spacer assembly are not blocked by opposing bushings, and 
the forward trunnion bolt does not reveal chrome flaking, or 
galling, and exhibits no corrosion in the grooves, no further work 
is required by this AD.
    (2) Condition 2. If the lubrication holes on the forward 
trunnion spacer assembly are blocked by opposing bushings, and the 
forward trunnion bolt does not reveal chrome flaking or galling, and 
exhibits no corrosion in the grooves: Prior to further flight, 
replace the forward trunnion spacer assembly with a new part in 
accordance with the service bulletin.
    (3) Condition 3. If the lubrication holes on the forward 
trunnion spacer assembly are blocked by opposing bushings, and the 
forward trunnion bolt reveals chrome flaking, galling, or corrosion 
in the grooves, accomplish either paragraph (b)(3)(i) or (b)(3)(ii) 
of this AD:
    (i) Option 1. Prior to further flight, replace the forward 
trunnion spacer assembly with a new part, and replace the forward 
trunnion bolt with a new part in accordance with the service 
bulletin. Or
    (ii) Option 2. Prior to further flight, replace the forward 
trunnion spacer assembly with a new part, and rework the forward 
trunnion bolt in accordance with the service bulletin.
    (c) 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.
    (d) 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 March 23, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8099 Filed 3-26-98; 8:45 am]
BILLING CODE 4910-13-P