[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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