[Federal Register Volume 63, Number 137 (Friday, July 17, 1998)]
[Rules and Regulations]
[Pages 38464-38466]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-19044]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-209-AD; Amendment 39-10665; AD 98-15-14]
RIN 2120-AA64
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 amendment supersedes an existing airworthiness directive
(AD), applicable to certain McDonnell Douglas Model MD-11 series
airplanes, that currently requires a revision of the Airplane Flight
Manual (AFM) to alert the flightcrew that both flight management
computers (FMC's) must be installed and operational. That AD also
requires an inspection to determine the serial number of the FMC's; and
[[Page 38465]]
follow-on corrective actions, if necessary, which terminate the AFM
revision. That amendment was prompted by a report indicating that, due
to incorrect multiplexers that were installed in the FMC's during
production, certain data busses failed simultaneously during a ground
test. This amendment removes the terminating action from the existing
AD. The actions specified in this AD are intended to prevent loss of
airspeed and altitude indications on both primary flight displays in
the cockpit, and/or loss or degradation of the autopilot functionality
due to installation of incorrect multiplexers, and consequent failure
of the data busses.
DATES: Effective August 3, 1998.
Comments for inclusion in the Rules Docket must be received on or
before September 15, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-209-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
Information pertaining to this rulemaking action may be examined 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.
FOR FURTHER INFORMATION CONTACT: Brett Portwood, Aerospace Engineer,
Systems and Equipment Branch, ANM-130L, FAA, Transport Airplane
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount
Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5350;
fax (562) 627-5210.
SUPPLEMENTARY INFORMATION: On April 28, 1998, the FAA issued AD 98-10-
01, amendment 39-10512 (63 FR 24742, May 5, 1998), applicable to
certain McDonnell Douglas Model MD-11 series airplanes. That AD
requires a revision of the Airplane Flight Manual (AFM) to alert the
flightcrew that both flight management computers (FMC's) must be
installed and operational. That AD also requires an inspection to
determine the serial number of the FMC's, and follow-on corrective
actions, if necessary; which terminate the AFM revision. That action
was prompted by a report indicating that, due to incorrect multiplexers
that were installed in the FMC's during production, certain data busses
failed simultaneously during a ground test. The actions required by
that AD are intended to prevent loss of airspeed and altitude
indications on both primary flight displays in the cockpit, and/or loss
or degradation of the autopilot functionality due to installation of
incorrect multiplexers, and consequent failure of the data busses.
Actions Since Issuance of Previous Rule
The existing AD requires terminating action for only a small
subgroup of affected airplanes (those with FMC multiplexers having
certain part numbers). However, since the issuance of that AD,
additional defective multiplexers (not previously identified) have been
found.
Airplanes having affected FMC's that have been purged of suspected
defective multiplexers, in compliance with AD 98-10-01, would be
considered airworthy. However, FMC's or mutliplexes may have been
exchanged or replaced during routine maintenance subsequent to
compliance with AD 98-10-01, and it would be impossible to determine
whether units inspected in accordance with that AD may now contain
suspected defective multiplexers. Therefore, the AFM revision will
continue to be required until the entire fleet can be systematically
inspected for suspected defective multiplexers. The AFM revision
requirement will ensure the continued safe operation of the entire
fleet during this interim period.
The AFM revision currently required by the existing AD, and
retained in this new action, requires that both FMC's be installed and
operational. The identified unsafe condition could not occur unless
both FMC's fail. Therefore, the FAA finds that the AFM limitation
adequately addresses the identified unsafe condition.
Interim Action
This is considered to be interim action. The FAA may consider
further rulemaking to require inspection of all MD-11 FMC's to detect
defective multiplexers. However, the compliance time under
consideration for these actions is sufficiently long so that notice and
opportunity for prior public comment will be practicable.
Explanation of Requirements of Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of this same type design, this AD
supersedes AD 98-10-01 to continue to require an AFM revision to alert
the flightcrew that both FMC's must be installed and operational. In
addition, this AD removes the terminating action required by AD 98-10-
01.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
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 98-NM-209-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
[[Page 38466]]
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, 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-10512 (63 FR
24742, May 5, 1998), and by adding a new airworthiness directive (AD),
amendment 39-10665, to read as follows:
98-15-14 McDonnell Douglas: Amendment 39-10665. Docket 98-NM-209-
AD. Supersedes AD 98-10-01, amendment 39-10512.
Applicability: Model MD-11 series airplanes, manufacturer's
fuselage numbers 0447 through 0552 inclusive, and 0554 through 0621
inclusive; 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 (b) 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 loss of airspeed and altitude indications on both
primary flight displays in the cockpit, and/or loss or degradation
of the autopilot functionality due to installation of incorrect
multiplexers, and consequent failure of the data busses, accomplish
the following:
(a) Within 5 days after May 20, 1998 (the effective date of AD
98-10-01, amendment 39-10512), revise Section 1, page 5-1, of the
Limitations Section of the FAA-approved Airplane Flight Manual (AFM)
to include the following statement. This may be accomplished by
inserting a copy of this AD into the AFM.
``Prior to dispatch of the airplane, both Flight Management
Computer 1 (FMC-1) and FMC-2 must be installed and operational.''
(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
Operations 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
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.
(d) This amendment becomes effective on August 3, 1998.
Issued in Renton, Washington, on July 10, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-19044 Filed 7-16-98; 8:45 am]
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