[Federal Register Volume 60, Number 4 (Friday, January 6, 1995)]
[Proposed Rules]
[Pages 2041-2043]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-308]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-175-AD]


Airworthiness Directives; McDonnell Douglas Model MD-11 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain McDonnell Douglas MD-11 
series airplanes. This proposal would require the installation of an 
electrically controlled slat system. This proposal is prompted by 
numerous incidents of inadvertent deployment of the slats while the 
airplane was in flight at cruise altitude. The actions specified by the 
proposed AD are intended to prevent inadvertent deployment of the slats 
during flight, which could result in an abrupt pitch up of the airplane 
and consequent injury to crew and passengers; it could also result in 
significant vibrations and cause damage to the elevators.

DATES: Comments must be received by March 3, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-175-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule 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 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.

FOR FURTHER INFORMATION CONTACT: Wahib Mina, Aerospace Engineer, 
Airframe Branch, ANM-120L, Los Angeles Aircraft Certification Office, 
FAA, Transport Airplane Directorate, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (310) 627-5324; fax (310) 
627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 94-NM-175-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 94-NM-175-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA previously has issued several AD's, applicable to McDonnell 
Douglas Model MD-11 series airplanes, whose requirements have addressed 
the problems associated with inadvertent deployment of the slats during 
flight:
    1. AD 92-13-03, amendment 39-8273 (57 FR 27155, June 18, 1992), 
requires either modification or replacement of the flap control module 
quadrant. That action was prompted by an incident in which a flightcrew 
member inadvertently bumped the flap/slat handle, which then placed the 
handle in an improper position that allowed the slats to extend during 
cruise.
    2. AD 92-14-51, amendment 39-8325 (57 FR 38264, August 24, 1992), 
requires a one-time inspection of the slat mechanical input system for 
proper clearance and rigging, and adjustment of the system, if 
necessary. That action was prompted by two incidents in which the slats 
extended during flight at cruise altitude because the rigging of the 
slat input system was out of tolerance in three separate places in the 
extended position
    3. AD 92-26-03, amendment 39-8430 (57 FR 57906, December 8, 1992), 
requires installing a cover on the flap/slat control module quadrant in 
the flight compartment. That action was prompted by an incident in 
which a flightcrew member inadvertently initiated slat deployment by 
unintentionally depressing the zero degree detent gate while the flap/
slat handle was stowed in the retracted detent and the handle was not 
in the proper position within the detent.
    4. AD 93-15-03, amendment 39-8649 (58 FR 41421, August 4, 1993), 
requires installing a retainer assembly on the upper pedestal flap/slat 
control module quadrant in the flight compartment. That action was 
prompted by several incidents in which flightcrew members accidentally 
bumped the flap/slat handle and the slats deployed during cruise.
    Deployment of the slats during flight at cruise altitude could 
result in abrupt pitch up of the airplane and consequent injury to crew 
and passengers; it could also create significant vibrations and cause 
damage to the elevators.
    In the preambles to those AD's, the FAA stated that the 
requirements of each of the AD's were considered to be interim action 
until final action was identified. The manufacturer had undertaken a 
design review of the flap/slat system of the Model MD-11 in an effort 
to positively address the problems associated with it, and the FAA 
indicated that it would consider further rulemaking once that design 
review was completed.
    The manufacturer's design review has now been completed and the 
manufacturer has developed an electrically controlled slat system. 
Installation of this new system will reduce the possibility of 
uncommanded operation of the slats and inadvertent displacement of the 
flap/slat handle. The FAA has determined that the system positively 
addresses the unsafe condition addressed in the previously-issued AD's. 
In light of this, the FAA has determined that further rulemaking action 
is indeed necessary, and this [[Page 2042]] proposed AD follows from 
that determination.
    The FAA has reviewed and approved McDonnell Douglas MD-11 Service 
Bulletin 27-36, Revision 1, dated December 9, 1994, which describes 
procedures for installation of the newly-designed electrically 
controlled slat system. This system involves:
    1. modifying and reidentifying the flap/slat module;
    2. removing the slat control cables and associated pulleys, 
pushrods, and spring coupler;
    3. modifying the input bellcrank;
    4. removing the inboard follow-up cable, drum, and pushrods to the 
outboard valve;
    5. removing the auto-slat actuator and pushrod;
    6. replacing the mechanical slat control valves with electro-
mechanical slat control valves and installing associated wiring;
    7. installing nameplates on the overhead circuit breaker panel;
    8. installing circuit breakers and nameplates on the avionics 
circuit breaker panel;
    9. installing relays at the electrical and main avionics rack; and
    10. installing lightplates on the pedestal.
    Besides its main purpose to reduce the possibility of uncommanded 
slat operation, other benefits of this new system include greatly 
simplified flap/slat operation with reduced handle force, enhanced 
protection against uncontained engine failure, and reduced aircraft 
weight.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require installation of an electrically controlled 
slat system. The actions would be required to be accomplished in 
accordance with the service bulletin described previously.
    Installation of this new system necessarily entails removal of the 
items that previously were required to be installed in accordance with 
AD's 92-13-03, 92-14-51, 92-26-03, and 93-15-03. Therefore, once the 
installation of the new system is completed on an airplane, the 
requirements of the previously-issued AD's are considered terminated.
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that 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 included to this notice to clarify this requirement.
    There are approximately 124 Model MD-11 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 43 
airplanes of U.S. registry would be affected by this proposed AD, that 
it would take approximately 68 work hours per airplane to accomplish 
the proposed actions, and that the average labor rate is $60 per work 
hour. Required parts would be supplied by the manufacturer at no charge 
to operators. Based on these figures, the total cost impact of the 
proposed AD on U.S. operators is estimated to be $175,440, or $4,080 
per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

McDonnell Douglas: Docket 94-NM-175-AD.

    Applicability: Model MD-11 series airplanes; as listed in 
McDonnell Douglas MD-11 Service Bulletin 27-36, Revision 1, dated 
December 9, 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 (c) 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 inadvertent deployment of the slats during flight, 
accomplish the following:
    (a) Within 24 months after the effective date of this AD, modify 
the airplane and install an electrically controlled slat control 
system in accordance with McDonnell Douglas MD-11 Service Bulletin 
27-36, Revision 1, dated December 9, 1994.
    (b) Accomplishment of the actions required by paragraph (a) of 
this AD constitutes terminating action for the requirements of the 
following AD's:

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                                         Amendment    Federal Register  
                 AD No.                     No.           citation      
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92-13-03...............................    39-8273  (57 FR 27155,       
                                                    June 18, 1992).     
92-14-51...............................    39-8325  (57 FR 38264,       
                                                    Aug. 24, 1992).     
[[Page 2043]]                                                           
                                                                        
92-26-03...............................    39-8430  (57 FR 57906,       
                                                    Dec. 8, 1992).      
93-15-03...............................    39-8649  (58 FR 41421,       
                                                    Aug. 4, 1993).      
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    (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 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.

    (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.

    Issued in Renton, Washington, on December 30, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-308 Filed 1-5-95; 8:45 am]
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