[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]
-----------------------------------------------------------------------
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).
-----------------------------------------------------------------------
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
