[Federal Register Volume 60, Number 149 (Thursday, August 3, 1995)]
[Rules and Regulations]
[Pages 39633-39635]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-18436]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-36-AD; Amendment 39-9322; AD 95-16-03]
Airworthiness Directives; McDonnell Douglas Model DC-9 Series
Airplanes and C-9 (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 Model DC-9 series airplanes and C-9 (military)
airplanes, that requires inspection of the driver links of the thrust
reverser door to determine whether the driver links are chamfered, an
inspection to detect damage of the overcenter links, and follow-on
corrective actions, if necessary; and replacement or rework of the
driver links. This amendment is prompted by reports of a thrust
reverser door that failed to operate properly due to improperly
manufactured (missing chamfers on the) driver links. The actions
specified by this AD are intended to prevent damage to the overcenter
links due to missing chamfers on the driver links, which may result in
uncommanded opening of the thrust reverser door, and subsequently,
adversely affecting controllability of the airplane.
DATES: Effective September 5, 1995.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 5, 1995.
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: Robert Baitoo, Aerospace Engineer,
Propulsion Branch, ANM-140L, FAA, Transport Airplane Directorate, Los
Angeles Aircraft Certification Office, 3960 Paramount Boulevard,
Lakewood, California 90712; telephone (310) 627-5245; 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 Model DC-9 series
airplanes and C-9 (military) airplanes was published in the Federal
Register on April 17, 1995 (60 FR 19188). That action proposed to
require a one-time visual inspection of the driver links of the thrust
reverser door to determine whether the driver links are chamfered, and
a one-time visual inspection to detect damage of the overcenter links,
and follow-on corrective actions, if necessary; and replacement or
rework of the driver links.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
One commenter requests a revision to the proposal to include an
option that would allow deactivation of a thrust reverser in accordance
with the Minimum Equipment List (MEL). Additionally, the commenter
states that if damage limits are required for driver links or
overcenter links that are installed on deactivated thrust reversers,
then McDonnell Douglas Alert Service Bulletin A78-67 (that is
referenced in the proposal as the appropriate source of service
information) should be revised to include those limits. The commenter
contends that the revised service bulletin should then be referenced in
the final rule as the appropriate source of service information. The
commenter states that this suggested change would minimize the impact
on scheduled service to the public.
The FAA does not concur. The FAA acknowledges that the MEL permits
continued operation of an airplane for up to 10 days with a deactivated
thrust reverser. However, the FAA's intent in issuing this AD is to
remove all defective driver links from the fleet in a timely manner so
as to preclude the potential for any further incidents of uncommanded
openings of the thrust reverser door after takeoff. Deactivation of the
thrust reverser would essentially extend the compliance time of this
AD; the FAA considers such extension to be unacceptable since the
affected fleet must be purged of the discrepant part in order to ensure
safety. Where there are differences between the MEL and the AD, the AD
takes precedence; therefore inspection, and any necessary replacement,
must be accomplished by affected operators within 3 months, as required
by this AD.
Further, the FAA does not concur with the commenter's request that
essentially would delay the issuance of this rule until the
manufacturer can release a revised service bulletin containing damage
limits for driver links and overcenter links that are installed on
deactivated thrust reversers. The FAA does not consider that delaying
this action until after the release of a revised service bulletin is
warranted or appropriate, since, as explained above, the FAA does not
concur with the commenter's request to permit flight with a deactivated
thrust reverser.
The same commenter also requests a revision to the proposal to
include an alternative to the proposed inspections
[[Page 39634]]
of the links. The commenter states that if no discrepant parts were
received then no inspection should be required. Therefore, the
commenter suggests including an alternative to permit operators to
check shipping records in lieu of performing the inspections.
The FAA does not concur. Discrepant links have the same part number
as those links that have chamfers. Therefore, discrepant links would
not be identifiable by checking shipping records.
Two commenters request a revision of the 3-month compliance time
proposed in paragraphs (a) and (b). One of these commenters requests
that the proposed compliance time be extended to 6 months. The other
commenter requests that the inspections be allowed to be accomplished
during the time of a normally scheduled ``C'' check. This commenter
states that adoption of a compliance time that coincides with
operators' ``C'' checks would minimize interruptions to the operators'
regularly scheduled maintenance.
The FAA does not concur. In developing an appropriate compliance
time for this action, the FAA considered not only the degree of urgency
associated with addressing the subject unsafe condition, but the
practical aspects of accomplishing the inspections within an interval
of time that parallels normally scheduled maintenance for the majority
of affected operators.
The FAA notes that the driver link and overcenter link assemblies
of the thrust reverser are commonly referred to as ``driver link and
overcenter link.'' Therefore, for purposes of clarification, paragraph
(d) of the final rule has been revised to delete the phrase ``assembly
of a thrust reverser'' following the terms ``driver link or overcenter
link.''
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.
There are approximately 892 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 557 airplanes of U.S. registry
will be affected by this AD, that it will take approximately 1 work
hour per airplane to accomplish the required inspections and 10 work
hours per airplane to accomplish the required replacement/rework, and
that the average labor rate is $60 per work hour. Required replacement/
rework parts will cost approximately $4,100 per airplane. Based on
these figures, the total cost impact of the AD on U.S. operators is
estimated to be $2,651,320, or $4,760 per airplane.
The total 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.
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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
95-16-03 McDonnell Douglas: Amendment 39-9322. Docket 95-NM-36-AD.
Applicability: Model DC-9-10, -20, -30, -40, and -50 series
airplanes, and C-9 (military) airplanes, as listed in McDonnell
Douglas DC-9 Alert Service Bulletin A78-67, dated February 27, 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 use the authority
provided in paragraph (e) of this AD to request approval from the
FAA. This approval may address either no action, if the current
configuration eliminates the unsafe condition; or different actions
necessary to address the unsafe condition described in this AD. Such
a request should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent uncommanded opening of the thrust reverser door,
which may adversely affect controllability of the airplane,
accomplish the following:
(a) Within 3 months after the effective date of this AD, perform
a visual inspection of the actuating mechanisms of the upper and
lower doors of the thrust reverser on the left and right engines to
determine whether the driver links are chamfered, in accordance with
McDonnell Douglas DC-9 Alert Service Bulletin A78-67, dated February
27, 1995.
(1) If all the driver links are chamfered, prior to further
flight, perform a visual inspection to detect damage of the
overcenter links (including the bearings, races, and attaching
hardware), in accordance with the alert service bulletin.
(i) If no damage to the overcenter links is detected, no further
action is required by this paragraph.
(ii) If any damage to the overcenter links is detected, prior to
further flight, replace the damaged overcenter links with new or
serviceable overcenter links in accordance with the alert service
bulletin.
(iii) If any damage to the bearings, races, or attaching
hardware of the overcenter links is detected, prior to further
flight, perform a visual inspection to detect damage of the drive
mechanism of the thrust reverser, in accordance with the alert
service bulletin. If any damage to the drive mechanism is detected,
prior to further flight, repair or replace the damaged parts with
new or serviceable parts, in accordance with the Chapter 78 of the
DC-9 Overhaul Manual.
(2) If any driver link is not chamfered, prior to further
flight, remove the driver link and perform dimensional and
fluorescent penetrant inspections to determine serviceability of the
driver link, in accordance with the alert service bulletin.
(i) If the driver link is serviceable, prior to further flight,
machine chamfer the driver link, or replace the driver link with a
new or
[[Page 39635]]
serviceable part, in accordance with the alert service bulletin.
(ii) If the driver link is not serviceable, prior to further
flight, replace it with a new or serviceable driver link, in
accordance with the alert service bulletin.
(b) Within 3 months after the effective date of this AD, perform
a visual inspection to detect damage of the overcenter links
(including the bearings, races, and attaching hardware, in
accordance with the McDonnell Douglas DC-9 Alert Service Bulletin
A78-67, dated February 27, 1995.
(1) If no damage to the overcenter links is detected, no further
action is required by this paragraph.
(2) If any damage to the overcenter links is detected, prior to
further flight, replace the damaged overcenter links with new or
serviceable overcenter links in accordance with the alert service
bulletin.
(3) If any damage to the bearings, races, or attaching hardware
of the overcenter links is detected, prior to further flight,
perform a visual inspection to detect damage of the drive mechanism
of the thrust reverser, in accordance with the alert service
bulletin. If any damage to the drive mechanism is detected, prior to
further flight, repair or replace the damaged parts with new or
serviceable parts, in accordance with the Chapter 78 of the DC-9
Overhaul Manual.
(c) Within 10 days after accomplishing the visual inspection of
the driver links of the thrust reverser door to determine whether
the driver links are chamfered, as required by paragraph (a) of this
AD, submit a report of the inspection results (both positive and
negative findings) to the Manager, FAA, Transport Airplane
Directorate, Los Angeles Aircraft Certification Office (ACO), 3960
Paramount Boulevard, Lakewood, California 90712; telephone (310)
627-5245; fax (310) 627-5210; Attention: Robert Baitoo. Information
collection requirements contained in this regulation have been
approved by the Office of Management and Budget (OMB) under the
provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et
seq.) and have been assigned OMB Control Number 2120-0056.
(d) As of the effective date of this AD, no person shall
install, on any airplane, a driver link or overcenter link that has
not been previously inspected, and replaced or reworked, in
accordance with McDonnell Douglas DC-9 Alert Service Bulletin A78-
67, dated February 27, 1995.
(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) Certain actions shall be done in accordance with McDonnell
Douglas DC-9 Alert Service Bulletin A78-67, dated February 27, 1995.
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 September 5, 1995.
Issued in Renton, Washington, on July 21, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-18436 Filed 8-2-95; 8:45 am]
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