[Federal Register Volume 60, Number 31 (Wednesday, February 15, 1995)]
[Rules and Regulations]
[Pages 8542-8543]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-2176]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-NM-144-AD; Amendment 39-9133; AD 95-02-14]
Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -
30, -40, and -50 Series Airplanes, and Model 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 McDonnell Douglas Model DC-9-10, -20, -30, -40,
and -50 series airplanes, and Model C-9 (military) airplanes, that
requires replacement of the engine nose cowl attaching bolts and the
installation of bearing plates on the nose cowl attach ring. This
amendment is prompted by incidents in which the nose cowl separated
from the airplane due to the elongation and/or breakout of the nose
cowl's attachment ring holes, and failure of the attaching bolts. The
actions specified by this AD are intended to prevent separation of the
engine nose cowl from the airplane, which could result in damage to the
airplane structure or could present a hazard to persons or property on
the ground.
DATES: Effective March 17, 1995.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 17, 1995.
ADDRESSES: The service information referenced in this AD may be
obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach,
California 90801-1771, Attention: Business Unit Manager, Technical
Administrative Support, Dept. L51, M.C. 2-98. 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, Los Angeles Aircraft Certification
Office, Transport Airplane Directorate, 3960 Paramount Boulevard,
Lakewood, California 90712-4137; 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 McDonnell Douglas Model
DC-9-10, -20, -30, -40, and -50 series airplanes, and Model C-9
(military) airplanes, was published in the Federal Register on October
18, 1994 (59 FR 52483). That action proposed to require replacement of
the engine nose cowl attaching bolts and the installation of bearing
plates on the nose cowl attach ring.
Discussion of Comments
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 supports the proposal.
Two commenters request that the proposed compliance time of 12
months for replacement be extended so that the required action can be
accomplished during regularly scheduled maintenance activities. One
commenter suggests a compliance time of 18 months; the other commenter
suggest a compliance time of 3,000 hours time-in-service. The FAA
concurs that the compliance time can be extended somewhat. 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 availability of required parts
and the practical aspect of accomplishing the required replacement on
the affected fleet in a timely manner. The FAA's intent was that the
replacement be conducted during a regularly scheduled maintenance visit
for the majority of the affected fleet, when the airplanes would be
located at a base where special equipment and trained personnel would
be readily available, if necessary. Based on the information supplied
by the commenters, the FAA now recognizes that 18 months corresponds
more closely to the interval representative of most of the affected
operators' normal maintenance schedules. Paragraph (a) of the final
rule has been revised to reflect a compliance time of 18 months. The
FAA does not consider that this extension will adversely affect safety.
One commenter questions the FAA's estimate of the cost of required
replacement parts. The commenter states that the $1,200 per airplane
figure, presented in the cost impact information in the preamble to the
notice, is too low. This commenter suggests that parts costs will be
approximately $15,700 per airplane. Upon further review, the FAA
concurs that the cost of required parts may be more than what was
previously estimated. The manufacturer has provided updated cost
figures for replacement bearing plates and bolts. If these items are
purchased directly from the manufacturer, the cost of replacement
bearing plates may be as much as $13,284 (36 plates at $369 each), and
the cost of replacement bolts may be as much as $1,900 (38 bolts at $50
each). However, the FAA points out that bearing plates can be
fabricated locally at a nominal cost, and bolts can be procured from
the operator's current stock, thereby reducing parts costs
considerably. The FAA has revised the cost impact information, below,
to include this updated information on the cost of required parts.
Discussion of Additional Changes to the Rule
Since issuance of the notice, the FAA has reviewed and approved
Revision 1 to McDonnell Douglas DC-9 Service Bulletin A71-63, dated
December 15, 1994. This revision is essentially identical to the
originally issued service bulletin, which was referenced in the notice
as the appropriate source of service information; however, it contains
certain editorial revisions and additional nose cowl part numbers. The
FAA has revised the final rule to include this revision of the service
bulletin as an additional source of service information.
As a result of recent communications with the Air Transport
Association (ATA) of America, the FAA has learned that, in general,
some operators may misunderstand the legal effect of AD's on airplanes
that are identified in the applicability provision of the AD, but that
have been altered or repaired in the area addressed by the AD. The FAA
points out that all airplanes identified in the applicability provision
of an AD are legally subject to the AD. If an airplane has been altered
or repaired in the affected area in such a way as to affect compliance
with the AD, the owner or operator is required to obtain FAA approval
for an alternative method of compliance with the AD, in accordance with
the paragraph of each AD that provides for such approvals. A note has
been added to this final rule to clarify this requirement.
[[Page 8543]]
Additionally, the FAA has recently reviewed the figures it has used
over the past several years in calculating the economic impact of AD
activity. In order to account for various inflationary costs in the
airline industry, the FAA has determined that it is necessary to
increase the labor rate used in these calculations from $55 per work
hour to $60 per work hour. The cost impact information, below, has been
revised to reflect this increase in the specified hourly labor rate.
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 892 Model DC-9-10, -20, -30, -40, and -50
series airplanes, and Model C-9 (military) 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.
It will take approximately 6 work hours per airplane to accomplish
the required replacement actions, at an average labor rate of $60 per
work hour. Required parts will vary in price, depending upon whether
they are purchased from the manufacturer, manufactured locally, or
procured from the operator's existing stocks. If all required parts (36
bearing plates and 38 bolts) are purchased from the manufacturer, the
cost could be as much as $15,184 per airplane. However, if the bearing
plates are manufactured locally and bolts are retrieved from the
operator's current stock, the estimated costs will be considerably
lower, approximately $1,900 per airplane.
Based on these figures, the total cost impact of the AD on U.S.
operators is estimated to be between $1,258,820 (or $2,260 per
airplane) and $8,658,008 (or $15,544 per airplane). This total cost
impact figure 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. 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:
95-02-14 McDonnell Douglas: Amendment 39-9133. Docket 94-NM-144-AD.
Applicability: Model DC-9-10, -20, -30, -40, and -50 series
airplanes, and Model C-9 (military) airplanes; as listed in
McDonnell Douglas DC-9 Alert Service Bulletin A71-63, dated July 21,
1994; 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 (b) 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 separation of the engine nose cowl from the airplane,
accomplish the following:
(a) Within 18 months after the effective date of this AD,
replace the left and right engine nose cowl attaching bolts and
install bearing plates, in accordance with McDonnell Douglas DC-9
Alert Service Bulletin A71-63, dated July 21, 1994; or Revision 1,
dated December 15, 1994.
(b) 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.
(c ) Special flight permits may be issued in accordance with
Secs. 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.
-(d) The replacement shall be done in accordance with McDonnell
Douglas DC-9 Alert Service Bulletin A71-63, dated July 21, 1994; or
McDonnell Douglas DC-9 Alert Service Bulletin A71-63, Revision 1,
dated December 15, 1994. 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, P.O. Box 1771, Long Beach, California
90801-1771, Attention: Business Unit Manager, Technical
Administrative Support, Dept. L51, M.C. 2-98. 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.
(e) This amendment becomes effective on March 17, 1995.
Issued in Renton, Washington, on January 24, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-2176 Filed 2-14-95; 8:45 am]
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