AD Amdt-39-11072

[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 99-5990]


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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.

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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