[Federal Register Volume 61, Number 96 (Thursday, May 16, 1996)]
[Rules and Regulations]
[Pages 24686-24688]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12148]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-191-AD; Amendment 39-9623; AD 96-10-16]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas MD-11 Series Airplane
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 MD-11 series airplanes,
that requires inspections to detect damage of the sidewall vent box
diaphragms, and repair, if necessary. This amendment also requires the
eventual installation of stops on the vent box diaphragm, which
terminates the inspection requirements of the AD. This amendment is
prompted by reports of damage to sidewall vent box diaphragms, which
can result in non-functional diaphragms during a rapid decompression.
The actions specified by this AD are intended to prevent buckling of
the floor beams due to insufficient air flow of the cabin sidewall vent
box diaphragms during rapid decompression, and consequent reduction in
the controllability of the airplane.
DATES: Effective June 20, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of June 20, 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: Andrew Gfrerer, Aerospace Engineer,
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft
Certification Office, 3960 Paramount Boulevard, Lakewood, California
90712; telephone (310) 627-5338; 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 MD-11 series airplanes
was published in the Federal Register on February 21, 1996 (61 FR
6581). That action proposed to require repetitive inspections to detect
damage of the sidewall vent box assemblies. Initially, that action
proposed to permit continued flight if only a certain number of
assembleis are found to be damaged. However, once that number is
exceeded, the damaged assemblies would be required to be modified,
prior to further flight, until the remaining number of damaged
assemblies does not exceed a certain number. That amendment also
proposed to require the eventual installation of stop pads for all vent
box diaphragms and reidentification of the assemblies,
[[Page 24687]]
which, when accomplished, terminates the requirement for the repetitive
inspections.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the two comments received.
Both commenters support the proposed rule.
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 as proposed.
Cost Impact
There are approximately 123 Model MD-11 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 39
airplanes of U.S. registry will be affected by this AD.
To accomplish the required inspections will take approximately 2
work hours per airplane, per inspection, at an average labor rate of
$60 per work hour. Based on these figures, the cost impact of the
required inspections on U.S. operators is estimated to be $4,680, or
$120 per airplane, per inspection cycle.
To accomplish the requried installation and reidentification will
take a total of approximately 270 work hours per airplane. This figure
represents 3 work hours per vent box, and up to a maximum of 90 vent
boxes on an airplane. The average labor rate is $60 per work hour. The
cost of requried parts will be negligible; the parts may be fabricated
locally. Based on these figures, the cost impact of the required
installation on U.S. operators is estimated to be $631,800, or $16,200
per airplane.
The cost impact figures 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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
96-10-16 McDonnell Douglas: Amendment 39-9623. Docket 95-NM-191-AD.
Applicability: Model MD-11 series airplane, as listed in
McDonnell Douglas Alert Service Bulletin MD11-25A181, dated
September 28, 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 (c) 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 prevent buckling of the floor beams due to insufficient air
flow of the cabin sidewalk vent box diaphragms during rapid
decompression, and subsequent loss of airplane control capabilities,
accomplish the following:
(a) Within 90 days after the effective date of this AD, perform
an inspection to detect damage of the sidewalk vent box diaphragms,
in accordance with McDonnell Douglas Alert Service Bulletin MD11-
25A181, dated September 28, 1995. Based on the findings of the
initial inspection, or any repetitive inspection, accomplish the
requirements of paragraph (a)(1), (a)(2), or (a)(3) of this AD, as
applicable:
(1) Condition 1. If no damage is detected: Repeat the inspection
at intervals not to exceed 90 days.
(2) Condition 2. If damage is detected, but the number of
damaged sidewall vent box assemblies does not exceed the applicable
allowable number specified in Table 1 of the alert service bulletin:
Repeat the inspection at intervals not to exceed 90 days.
(3) Condition 3. If damage is detected, and the number of
damaged vent box assemblies exceeds the applicable number specified
in Table 1 of the alert service bulletin: Prior to further flight,
install stops on and re-identify as many damaged sidewall vent box
assemblies as necessary so that the total number of damaged vent box
assemblies does not exceed the applicable allowable number specified
in Table 1 of the alert service bulletin. Accomplish the
installation of the stops and reidentification of the assemblies in
accordance with the alert service bulletin. The installation of
stops on and reidentification of an assembly constitutes terminating
action for the repetitive inspections of that assembly only. All
other assemblies must continue to be inspected thereafter at
intervals not to exceed 90 days.
(b) Within 30 months after the effective date of this AD,
install stops on and reidentify all sidewalk vent box assemblies
that do not already have stops installed and have not been
reidentified in accordance with McDonnell Douglas Alert Service
Bulletin MD11-25A181, dated September 28, 1995. Accomplishment of
this action constitutes terminating action for the inspection
requirements of this AD.
(c) 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 Inspectors, 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.
(d) 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.
(e) The inspections and installations shall be done in
accordance with McDonnell Douglas Alert Service Bulletin MD11-
25A181, dated September 28, 1995. This incorporation by reference
was approved by
[[Page 24688]]
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.
(f) This amendment becomes effective on June 20, 1996.
Issued in Renton, Washington, on May 9, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-12148 Filed 5-15-96; 8:45 am]
BILLING CODE 4910-13-M
