[Federal Register Volume 60, Number 13 (Friday, January 20, 1995)]
[Rules and Regulations]
[Pages 4076-4078]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-793]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-234-AD; Amendment 39-9120; AD 94-26-51]


Airworthiness Directives; McDonnell Douglas Model MD-11 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) T94-26-51 that was sent 
previously to all known U.S. owners and operators of all McDonnell 
Douglas Model MD-11 series airplanes by individual telegrams. This AD 
requires a revision to the FAA-approved Airplane Flight Manual (AFM) to 
prohibit autoland operation below 100 feet above ground level (AGL), 
and the installation of certain flight control computer software. This 
AD provides for an optional terminating action for the AFM revision. 
This amendment is prompted by reports of a loose nut on a coaxial 
connector on a radio altimeter receiver/transmitter rack, and the 
transmittal of erroneous altitude data to the flight control computers 
below 100 feet AGL, which resulted in abnormal flare (pitch) control 
during autoland operation. The actions specified by this AD are 
intended to prevent abnormal flare (pitch) control, which could result 
in degradation of the landing capability of the airplane.

DATES: Effective February 6, 1995, to all persons except those persons 
to whom it was made immediately effective by telegraphic AD T94-26-51, 
issued December 19, 1994, which contained the requirements of this 
amendment.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 6, 1995.
    Comments for inclusion in the Rules Docket must be received on or 
before March 21, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-234-AD, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056.
    The applicable service information 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; the FAA, Transport Airplane Directorate, Los Angeles 
Aircraft Certification Office, 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: Brett Portwood, Aerospace Engineer, 
Systems and Equipment Branch, ANM-132L, FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount 
Boulevard, Lakewood, California 90712; telephone (310) 627-5347; fax 
(310) 627-5210.

SUPPLEMENTARY INFORMATION: On December 19, 1994, the FAA issued 
telegraphic AD T94-26-51, which is applicable to all McDonnell Douglas 
Model MD-11 series airplanes.
    That action was prompted by two reports of abnormal flare (pitch) 
control that occurred during autoland operation on McDonnell Douglas 
Model MD-11 series airplanes. McDonnell Douglas reported that, during 
one occurrence, radio altimeter #1 transmitted erroneous altitude data 
to the flight control computers below 100 feet above ground level 
(AGL). This condition caused the airplane to flare prematurely during 
landing. Following a subsequent occurrence of abnormal autoland 
operation, an operator noticed that a nut on a coaxial connector on the 
back of the radio altimeter receiver/transmitter rack was loose. After 
refastening the connector, the airplane exhibited normal flare during 
autoland operation.
    Subsequent investigation of these reports conducted by McDonnell 
Douglas revealed that signals leaked between the transmitter and 
receiver of radio altimeter #1. The cause of this leakage has not yet 
been determined. In addition, the exact failure mode of the radio 
altimeter coaxial cable that can produce the leakage is unclear at this 
time. The manufacturer is conducting an investigation into the cause of 
this leakage in order to develop a corrective action.
    Early and/or abnormal flare (pitch) control during autoland 
operation, if not corrected, could result in degradation of the landing 
capability of the airplane. [[Page 4077]] 
    The FAA has reviewed and approved McDonnell Douglas MD-11 Alert 
Service Bulletin A34-57, dated December 19, 1994, which describes 
procedures for repetitive inspections to determine if the connector nut 
of the four coaxial connectors on the back of the radio altimeter 
receiver/transmitter is loose; repetitive leakage indication tests to 
verify the integrity of the radio altimeter antenna system; and 
correction of any discrepancy.
    The alert service bulletin references McDonnell Douglas MD-11 
Service Bulletin 22-14, dated November 30, 1994, which describes 
procedures for installation of -905 flight control computer (FCC) 
software. Accomplishment of this installation will provide additional 
protection against the effects of other discrepancies that may exist in 
the radio altimeter antenna system.
    Since the unsafe condition described is likely to exist or develop 
on other airplanes of the same type design, the FAA issued Telegraphic 
AD T94-26-51 to require a revision to the FAA-approved Airplane Flight 
Manual (AFM) to prohibit autoland operation below 100 feet AGL.
    This AD also provides for an optional terminating action for the 
AFM revision. The optional terminating action consists of:
    1. Performing repetitive inspections to determine if the connector 
nut of the four coaxial connectors on the back of the radio altimeter 
receiver/transmitter is loose, and tightening the nut, if necessary; 
and
    2. Performing repetitive leakage indication tests to verify the 
integrity of the radio altimeter antenna system, and correction of any 
discrepancy found.
    These actions, if accomplished, are required to be accomplished in 
accordance with McDonnell Douglas MD-11 Alert Service Bulletin A34-57, 
dated December 19, 1994, as described previously.
    This AD also requires installation of -905 FCC software. The 
installation is required to be accomplished in accordance with 
McDonnell Douglas MD-11 Service Bulletin 22-14, as described 
previously.
    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.
    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 included in this rule to clarify this requirement.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual telegrams 
issued on December 19, 1994, to all known U.S. owners and operators of 
McDonnell Douglas Model MD-11 series airplanes. These conditions still 
exist, and the AD is hereby published in the Federal Register as an 
amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 
39.13) to make it effective to all persons.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 94-NM-234-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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. [[Page 4078]] 


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-26-51 McDonnell Douglas: Amendment 39-9120. Docket 94-NM-234-AD.

    Applicability: All Model MD-11 series airplanes, 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 (d) 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 degradation of the landing capability of these 
airplanes, accomplish the following:
    (a) Within 24 hours after the effective date of this AD, revise 
the Limitations Section of the FAA-approved MD-11 Airplane Flight 
Manual (AFM), page 5-3, Flight Guidance, Automatic Landing Section, 
to include the following restriction. This may be accomplished by 
inserting a copy of this AD in the AFM.
    ``Autoland operation below 100 feet above ground level (AGL) is 
prohibited. The autopilot must be disconnected prior to descent 
below 100 feet AGL.''
    (b) Accomplishment of the inspections and tests specified in 
paragraphs (b)(1) and (b)(2) of this AD, in accordance with 
McDonnell Douglas MD-11 Alert Service Bulletin A34-57, dated 
December 19, 1994, constitutes terminating action for the AFM 
revision required by paragraph (a) of this AD. Following 
accomplishment of the inspections and tests, the AFM revision may be 
removed from the AFM.
    (1) Perform an inspection to determine if the connector nut of 
the four coaxial connectors on the back of the radio altimeter 
receiver/transmitter is loose.
    (i) If no loose nut is found, prior to further flight, loosen 
the nut until finger tight, retorque the nut to 10 to 15 inch 
pounds, and mark the nut with a torque stripe. Thereafter, repeat 
the inspection at intervals not to exceed 500 hours time-in-service.
    (ii) If any loose nut is found, prior to further flight, tighten 
the nut to a torque of 10 to 15 inch pounds, and mark the nut with a 
torque stripe. Thereafter, repeat the inspection at intervals not to 
exceed 500 hours time-in-service.

    Note 2: Retorque is not necessary during repetitive inspections 
if the torque stripe is in line, as specified in the alert service 
bulletin.

    (2) Perform a leakage indication test to verify the integrity of 
the radio altimeter antenna system. Prior to further flight, correct 
any discrepancy found. Thereafter, repeat the test at intervals not 
to exceed 500 hours time-in-service.
    (c) Within 15 days after the effective date of this AD, install 
-905 flight control computer (FCC) software in accordance with 
McDonnell Douglas MD-11 Service Bulletin 22-14, dated November 30, 
1994.
    (d) 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 
Operations Inspector, who may add comments and then send it to the 
Manager, Los Angeles ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (e) 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.
    (f) The inspections, tests, and installation shall be done in 
accordance with McDonnell Douglas MD-11 Alert Service Bulletin A34-
57, dated December 19, 1994; and McDonnell Douglas MD-11 Service 
Bulletin 22-14, dated November 30, 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, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3960 
Paramount Boulevard, Lakewood, California; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (g) This amendment becomes effective on February 6, 1995, to all 
persons except those persons to whom it was made immediately 
effective by telegraphic AD T94-26-51, issued on December 19, 1994, 
which contained the requirements of this amendment.

    Issued in Renton, Washington, on January 6, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-793 Filed 1-19-95; 8:45 am]
BILLING CODE 4910-13-U