[Federal Register Volume 64, Number 48 (Friday, March 12, 1999)]
[Rules and Regulations]
[Pages 12249-12252]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-5990]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-55-AD; Amendment 39-11072; AD 99-06-08]
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: Final rule.
-----------------------------------------------------------------------
SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain McDonnell Douglas Model DC-10 and MD-11 series
airplanes, and KC-10 (military) series airplanes, that requires 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 amendment 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
this 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: Effective April 16, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of April 16, 1999.
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Aircraft Group, Long Beach 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 Federal
[[Page 12250]]
Aviation Administration (FAA), Transport Airplane Directorate, Rules
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA,
Transport Airplane Directorate, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California; or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC.
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: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain McDonnell Douglas Model
DC-10 and MD-11 series airplanes, and KC-10 (military) series airplanes
was published in the Federal Register on March 27, 1998 (63 FR 14851).
That action proposed to 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.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Request To Extend Compliance Time for Initial Inspections
Several commenters request that the proposed compliance time be
revised from 18 to 24 months (for Model DC-10 series airplanes) and
from 15 to 24 months (for Model MD-11 series airplanes). In support of
this request, the commenters state that the time required to accomplish
the inspection is actually 18 or more work hours, not 1 work hour, as
estimated in the proposed rule. The commenters add that the referenced
service bulletins recommend a compliance time of 24 months.
The commenters also note that many of the affected airplanes were
inspected for chrome flaking of the trunnion bolt in accordance with
two existing AD's, and any corrosion would have been discovered at that
time. [The two existing AD's are: AD 96-03-05, amendment 39-9502 (61 FR
5281, February 12, 1996); and AD 96-16-01, amendment 39-9701 (61 FR
39312, July 29, 1996), which affect Model MD-11 series airplanes and
DC-10-30, DC-10-40, and KC-10A (military) airplanes, and Model DC-10-10
and -15 series airplanes, respectively.]
One commenter indicates that in cases where discrepant spacers were
found, the airplanes had been in service for five to eight years, and
that it is not uncommon to find corrosion on the trunnion bolts during
overhaul (after eight years of service). The commenters estimate an
eight- to nine-month lead time for replacement parts if discrepant
spacers are found during accomplishment of the proposed inspection.
The FAA concurs with the commenter's request to extend the
compliance time. Although the FAA determined that a 24-month compliance
time would not address the identified unsafe condition in a timely
manner, as was described in the preamble to the notice, the FAA has
reconsidered its position in light of the commenters' remarks.
The FAA finds that the requirements of AD's 96-16-01 and 96-03-05
are similar to those required in this AD. Therefore, the exposure of
corrosion as the result of chrome flaking on the trunnion bolts is much
less than if the trunnion bolts had not been inspected. In addition,
service history does indicate that discrepant spacers were found on
airplanes with five to eight years of service.
In the preamble of the notice, the FAA indicated that it would take
less than one work hour to perform the inspections by discounting the
time to access the subject inspection area. In many cases during
maintenance, operators have access to an inspection area; however, this
is not true of the subject inspection area of this AD. The FAA finds
that, as suggested by the commenters, it will take approximately 18
work hours to accomplish the required inspections. This work hour
estimate is in consonance with that specified in the referenced service
bulletin.
In light of these findings, the FAA finds that extending the
compliance time by 6 (for Model DC-10 series airplanes) and 9 (for
Model MD-11 series airplanes) additional months will not adversely
affect safety. Therefore, the FAA has revised paragraphs (a) and (b) of
the final rule to specify a compliance time of 24 months. In addition,
the FAA has revised the cost impact information, below, to include the
updated work hours for the required inspections.
Request To Revise Cost Estimate
Several commenters request that the FAA revise the estimated number
of work hours required to accomplish the proposed actions. The
commenters note that only one work hour was specified in the proposed
AD; however, access time is estimated to be at least 17 work hours. The
commenters indicate that this type of action would not normally be
addressed during regularly scheduled maintenance. One commenter
estimates that the proposed action would require 50 work hours and 25
elapsed hours. Another commenter estimates a total of 80 work hours.
The FAA concurs with the commenters' request to revise the
estimated number of work hours. However, as discussed previously, the
FAA finds that it will take approximately 18 work hours, as specified
in the referenced service bulletin, to accomplish the required
inspections. The final rule has been revised accordingly.
Request To Extend Compliance Time for Certain Airplanes
One commenter requests that the FAA allow a 48-month compliance
time for airplanes on which the requirements of AD 96-03-05 have been
accomplished. The commenter indicates that, during accomplishment of
that AD, any corrosion would have been discovered. In addition, if
chrome flaking was discovered, the trunnion bolts would have been
replaced with new bolts having the most corrosion resistant properties
provided on those parts.
The FAA concurs partially. As discussed previously, the FAA notes
that AD 96-03-05 and AD 96-16-01 both address chrome flaking of the
trunnion bolt. If corrosion were found and the bolts replaced in
accordance with either of these AD's, the lubrication blockage
addressed in this AD could have been a cause of that corrosion.
Therefore, only specific conditions from AD 96-03-05 and AD 96-16-01
would be applicable and, in some cases, it would be necessary for the
operator to have kept records that corrosion was not discovered.
Therefore, the FAA has added paragraphs (c), (d), and (e) to this final
rule to allow operators that accomplished certain paragraphs of those
AD's to accomplish the required one-time visual inspection within 48
months.
Request To Allow Time To Obtain Parts
One commenter requests that if a discrepant spacer assembly is
found, the FAA should allow time to obtain a new part instead of
requiring repair before further flight. The commenter states that two
techniques are being developed by Douglas Products Division (DPD),
which
[[Page 12251]]
would allow for an inspection of the discrepant spacer without
disassembly. In addition, the commenter indicates that an airplane was
flown without failure for eight years with a discrepant spacer.
The FAA does not concur with the commenter's request. The blocked
lubrication holes do not allow lubrication to reach the trunnion bolt.
This condition can accelerate corrosion damage to the bolt, which could
lead to the identified unsafe condition. An airplane that was in
service for eight years may not have been subjected to loads that could
contribute to failure of the bolt. However, another airplane may be in
service for an even shorter period of time and yet experience loads
that could lead to failure of a corroded bolt. Therefore, the FAA finds
that repair of any discrepant spacer assembly prior to further flight
is warranted.
Request for Alternate Inspection Procedure
One commenter requests that the FAA allow the use of a newly
developed x-ray inspection technique that would allow for an inspection
without disassembly of the structure. The commenter indicates that this
would reduce operator time and effort without jeopardizing safety.
The FAA does not concur with the commenter's request. The FAA is
aware that DPD is attempting to develop alternative inspection
procedures. However, since those procedures have not been provided to
the FAA, it cannot approve the alternative inspection technique at this
time.
Request To Allow Replacement of Spacers With Reworked Spacers
One commenter requests that the FAA allow discrepant spacers to be
reworked in accordance with Chapter 32-10-01 of Douglas Aircraft
Company Component Maintenance Manual. The commenter contends that
allowing rework of the spacers to an acceptable condition would reduce
the economic impact on the fleet. The FAA concurs. The FAA has revised
paragraphs (a)(2), (a)(3)(i), (a)(3)(ii), (b)(2), (b)(3)(i), and
(b)(3)(ii) of the final rule to allow replacement of any discrepant
forward trunnion spacer assembly with a part that has been reworked in
accordance with Chapter 32-10-01 of Douglas Aircraft Company Component
Maintenance Manual.
Conclusion
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 previously
described. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Cost Impact
There are approximately 522 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 326 airplanes of U.S. registry
will be affected by this AD, that it will take approximately 18 work
hours per airplane to accomplish the required inspection, and that the
average labor rate is $60 per work hour. Based on these figures, the
cost impact of the AD on U.S. operators is estimated to be $352,080, or
$1,080 per airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the 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 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 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
99-06-08 McDonnell Douglas: Amendment 39-11072. 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 (f) 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: Except as provided by
paragraphs (c) and (d) of this AD, within 24 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
[[Page 12252]]
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, or with a part
that has been reworked in accordance with Chapter 32-10-01 of
Douglas Aircraft Company Component Maintenance Manual.
(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 in accordance with the
service bulletin, or with a part that has been reworked in
accordance with Chapter 32-10-01 of Douglas Aircraft Company
Component Maintenance Manual; 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 in accordance with the
service bulletin, or with a part that has been reworked in
accordance with Chapter 32-10-01 of Douglas Aircraft Company
Component Maintenance Manual; 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: Except as provided by
paragraph (e) of this AD, within 24 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, or with a part that has been
reworked in accordance with Chapter 32-10-01 of Douglas Aircraft
Company Component Maintenance Manual.
(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 in accordance with the
service bulletin, or with a part that has been reworked in
accordance with Chapter 32-10-01 of Douglas Aircraft Company
Component Maintenance Manual; 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 in accordance with the
service bulletin, or with a part that has been reworked in
accordance with Chapter 32-10-01 of Douglas Aircraft Company
Component Maintenance Manual; and rework the forward trunnion bolt
in accordance with the service bulletin.
(c) For Model MD-11 series airplanes on which the requirements
specified in either paragraph (a)(2) or (b) of AD 96-03-05,
amendment 39-9502, have been accomplished: Within 48 months after
the effective date of this AD, accomplish the requirements specified
in paragraph (a) of this AD.
(d) For Model DC-10-30, DC-10-40, and KC-10A (military) series
airplanes on which the requirements specified in either paragraph
(c)(1)(i) or (c)(2)(ii) of AD 96-03-05, amendment 39-9502, have been
accomplished: Within 48 months after the effective date of this AD,
accomplish the requirements specified in paragraph (a) of this AD.
(e) For Model DC-10-10 and DC-10-15 series airplanes, on which
the requirements specified in paragraph (a)(1)(i), (a)(2)(ii),
(b)(2)(i), or (b)(2)(ii) of AD 96-16-01, amendment 39-9701, have
been accomplished: Within 48 months after the effective date of this
AD, accomplish the requirements specified in paragraph (a) of this
AD.
(f) 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.
(g) 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.
(h) The inspections and replacements shall be done in accordance
with McDonnell Douglas Service Bulletin MD11-32-074, dated December
15, 1997; or McDonnell Douglas Service Bulletin DC10-32-248, dated
December 17, 1997; as applicable. This incorporation by reference
was approved by the Director of the Federal Register in accordance
with 5 U.S.C. 552(a) and 1 CFR part 51. Copies 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). Copies
may be inspected 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; or at the Office of
the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
(i) This amendment becomes effective on April 16, 1999.
Issued in Renton, Washington, on March 4, 1999.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-5990 Filed 3-11-99; 8:45 am]
BILLING CODE 4910-13-U
