[Federal Register Volume 61, Number 132 (Tuesday, July 9, 1996)]
[Rules and Regulations]
[Pages 35944-35946]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-16951]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-254-AD; Amendment 39-9686; AD 96-14-04]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-10 and MD-11
Series Airplanes, and KC-10A (Military) 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-10A (military) airplanes, that requires identifying
and replacing certain lock link bolts in the nose landing gear (NLG).
This amendment is prompted by a report indicating that certain bolts
were improperly heat-treated during manufacturing, which makes them
prone to failure. The actions specified by this AD are intended to
prevent failure of the lock link bolts in the NLG, which could result
in the collapse of the NLG.
DATES: Effective August 13, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of August 13, 1996.
ADDRESSES: The service information referenced in this AD may be
obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard,
Long Beach, California 90846, Attention: Technical Publications
Business Administration, Department C1-L51 (2-60). This information may
be examined at the Federal Aviation Administration (FAA), Transport
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton,
Washington; or at the FAA, Los Angeles Aircraft Certification Office,
Transport Airplane Directorate, 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: Wahib Mina, Aerospace Engineer,
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone
(310) 627-5324; fax (310) 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-10A (military) airplanes was
published in the Federal Register on March 18, 1996 (61 FR 10907). That
action proposed to require a one-time visual inspection to identify
suspect lock link bolts, and the replacement of those bolts with new
serviceable bolts.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Support for the Proposal
Four commenters support the proposal.
Request To Allow Records Search in Lieu of Inspection
One commenter requests that the proposed rule be revised to allow
operators to conduct a records search to determine if airplanes are
equipped with the suspect bolt, rather than conduct an inspection of
every airplane in order to determine if the bolt is installed. This
commenter states that, for some operators, the NLG lock link bolts are
required to have a tracking history (i.e., records track the bolt by
serial number). For these operators, it would be more economically
feasible, and just as productive, to conduct a records search in lieu
of an inspection.
The FAA concurs. Paragraph (a) of the final rule has been revised
to provide for the option of conducting a records search.
Request To Extend the Compliance Time for Replacement
Several commenters request that the proposed rule be revised to
allow operators to replace suspect bolts at a later time. These
commenters request that, instead of requiring that a suspect bolt be
replaced prior to further flight after the inspection is accomplished,
the proposed rule should permit operators to replace the bolt at any
time after the inspection, but prior to the end of the 24-month
compliance time. These commenters consider that this extension of the
replacement time will obtain the same result as intended by the FAA,
and will have a less disruptive impact on operators' schedules.
The FAA concurs that the bolts need not be replaced prior to
further flight after the inspection (or records search) is
accomplished. The FAA makes this finding based on the following data
pertinent to the configuration of the suspect bolts themselves:
1. None of the suspect bolts were manufactured prior the initial
production of the Model MD-11 series airplanes (in 1991). In light of
this, the FAA is confident that none of the suspect bolts was installed
as original equipment on any of the affected Model DC-10 series
airplanes. (Model DC-10's have been produced since 1971.)
2. The suspect bolts were manufactured using a process that did not
affect their static strength requirement, but did reduce their fatigue
life. These bolts should have a fatigue life in the range of 58,281
landings; due to the manufacturing process used, however, the fatigue
life
[[Page 35945]]
of the suspect bolts has been reduced to approximately 24,638 landings.
3. A review of the utilization rates of the current worldwide fleet
indicates that the highest number of landings accumulated on any Model
MD-11 series airplane is approximately 5,000 landings.
4. The average annual utilization rate of the airplanes affected by
this AD is between 1,000 and 1,200 landings.
These data indicate that, if any suspect bolt had been installed as
original equipment on a Model MD-11 (even those airplanes with the
highest number of landings accumulated so far), or installed as a
replacement component on a Model DC-10, the fatigue life ``remaining''
on any suspect bolt is long enough to permit continued use of that bolt
for a 24-month period.
Based on these factors, the FAA has determined that a large enough
margin of safety exists so that replacement of the suspect bolts may be
accomplished within 24 months after the effective date of this AD,
regardless of when the inspection (or records search) is performed.
Paragraph (c) of the final rule has been revised to specify this.
Request To Permit Replacement With Other Than New Bolts
One commenter, the airframe manufacturer, requests that the
proposed rule be revised to delete the requirement that a ``new'' bolt
be used as a replacement bolt. This commenter states that the use of
the term ``new'' excludes the use of refurbished or serviceable bolts
that do not have one of the suspect serial numbers.
The FAA concurs. Serviceable (non-suspect) bolts are acceptable as
replacement parts. Accordingly, paragraph (c) of the final rule has
been revised to delete the word ``new'' from the description of
required replacement bolts.
Request To Ensure Availability of Replacement Parts
One commenter expresses concerns that the replacement bolts will
not be available in a timely manner. This commenter states that several
service bulletins recently have been released by McDonnell Douglas that
recommend inspections and replacement of high-strength landing gear
parts that were improperly heat-treated. This commenter is concerned
that the bolt suppliers may not be able to meet the concurrent demand
for the large quantity of parts needed for the entire affected fleet.
The FAA acknowledges this commenters concerns, and just recently
contacted the manufacturer on this very subject. The manufacturer has
assured the FAA that its suppliers stand ready to meet the demand for
parts for the total fleet.
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 565 Model DC-10 and MD-11 series airplanes
and KC-10A (military airplanes) of the affected design in the worldwide
fleet. The FAA estimates that 334 airplanes of U.S. registry will be
affected by this proposed AD.
It will take approximately .5 work hour per airplane to accomplish
either a one-time inspection or a commensurate records search, at an
average labor rate of $60 per work hour. Based on these figures, the
cost impact of the AD on U.S. operators is estimated to be $10,020, or
$30 per airplane.
If a suspect lock link bolt is found to be installed on an
airplane, its removal and replacement will take approximately 3 work
hours to accomplish, at an average labor rate of $60 per work hour.
(For operators of Model MD-11 series airplanes, the manufacturer has
indicated that it will reimburse operators for certain of these labor
costs as a labor credit allowance.) Replacement parts will be supplied
by the manufacture at no charge to operators. Based on these figures,
the cost impact of the replacement action on U.S. operators is
estimated to be $180 per airplane.
The cost impact figures discussed above are 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:
96-14-04 McDonnell Douglas: Amendment 39-9686. Docket 95-NM-254-AD.
Applicability: Model DC-10-10, -15, -30, and -40 series
airplanes, and KC-10A airplanes, as listed in McDonnell Douglas
Service Bulletin DC10-32-242, dated November 1, 1995; and Model MD-
11 series airplanes as listed in McDonnell Douglas Service Bulletin
MD11-32-060, dated November 6, 1995; 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 (e) 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.
[[Page 35946]]
Compliance: Required as indicated, unless accomplished
previously.
To prevent collapse of the nose landing gear as a result of
failure of the lock link bolt, accomplish the following:
(a) Within 24 months after the effective date of this AD,
perform either a visual inspection or a records search to determine
the serial number of the lock link bolt, part number (P/N) ACG7079-
1, installed in the nose landing gear (NLG). If the visual
inspection is accomplished, it must be conducted in accordance with
procedures specified in McDonnell Douglas Service Bulletin DC10-32-
242, dated November 1, 1995, for Model DC-10 series airplanes; or
McDonnell Douglas Service Bulletin MD11-32-060, dated November 6,
1995, for Model MD-11 series airplanes.
(b) If the serial number of the lock link bolt is not AP001
through AP036 inclusive, or AP200 through AP344 inclusive: No
further action is required by this AD.
(c) If the serial number of the lock link bolt is AP001 through
AP036 inclusive, or AP200 through AP344 inclusive: Within 24 months
after the effective date of this AD, replace the lock link bolt with
a bolt, P/N ACG7079-1, that does not have one of those serial
numbers.
(d) As of the effective date of this AD, no person shall install
a lock link bolt, part number (P/N) ACG7079-1, having a serial
number of AP001 through AP036 inclusive, or AP200 through AP344
inclusive, on any airplane.
(e) 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.
(f) 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.
(g) The inspection shall be done in accordance with McDonnell
Douglas Service Bulletin DC10-32-242, dated November 1, 1995, for
Model DC-10 series airplanes; and McDonnell Douglas Service Bulletin
MD11-32-060, dated November 6, 1995, for Model MD-11 series
airplanes. 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 McDonnell Douglas
Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846,
Attention: Technical Publications Business Administration,
Department C1-L51 (2-60). Copies may be inspected at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington; or at the FAA, Los Angeles Aircraft Certification
Office, Transport Airplane Directorate, 3960 Paramount Boulevard,
Lakewood, California; or at the Office of the Federal Register, 800
North Capitol Street, NW., suite 700, Washington, DC.
(h) This amendment becomes effective on August 13, 1996.
Issued in Renton, Washington, on June 27, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-16951 Filed 7-8-96; 8:45 am]
BILLING CODE 4910-13-P
