[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
