[Federal Register Volume 60, Number 28 (Friday, February 10, 1995)]
[Proposed Rules]
[Pages 7924-7925]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-3358]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-NM-70-AD]
Airworthiness Directives; McDonnell Douglas Model DC-10 Series
Airplanes and Model KC-10A (Military) Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Proposed rule; withdrawal.
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SUMMARY: This action withdraws a notice of proposed rulemaking (NPRM)
that proposed a new airworthiness directive (AD), applicable to all
McDonnell Douglas Model DC-10 series airplanes and Model KC-10A
(military) airplanes. That action would have required modification of
the fuel crossfeed dump shutoff system. Since the issuance of the NPRM,
the Federal Aviation Administration (FAA) has determined that other
means are in place that adequately address the unsafe condition.
Accordingly, the proposed rule is withdrawn.
FOR FURTHER INFORMATION CONTACT: Ray Vakili, Aerospace Engineer,
Propulsion Branch, ANM-141L, FAA, Transport Airplane Directorate, Los
Angeles Aircraft Certification Office, 3960 Paramount Boulevard,
Lakewood, California 90712; telephone (310) 627-5262; fax (310) 627-
5210.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to add a new airworthiness
directive (AD), applicable to all McDonnell Douglas Model DC-10 series
airplanes and Model KC-10A (military) airplanes, was published in the
Federal Register as a Notice of Proposed Rulemaking (NPRM) on July 27,
1994 (59 FR 38141). The proposed rule would have required modification
of the fuel crossfeed dump shutoff system. That action was prompted by
an FAA determination that, in the event of a failure of the number 2
bus tie relay and subsequent loss of the electrical power source of the
number 2 engine, an all-engine flameout event could occur due to fuel
starvation during or shortly after a fuel dumping operation. The
proposed actions were intended to prevent loss of the fuel crossfeed
dump shutoff system due to a failure of the number 2 DC bus electrical
relay and subsequent loss of the electrical power source of the number
2 engine.
Interested persons have been afforded an opportunity to comment on
the proposal. Due consideration has been given to the comments
received.
The majority of commenters request that the proposed rule be
withdrawn for several reasons:
First, the commenters reference AD 92-22-06, amendment 39-8392 (57
FR 47570, October 19, 1992), applicable to Model MD-11 and DC-10 series
airplanes and Model KC-10A (military) airplanes, which was cited in the
preamble to the notice. That AD requires revising the Airplane Flight
Manual (AFM) to include information to specify that electrical
malfunctions may render the automatic fuel dump termination feature
inoperative. That AD was prompted by an incident in which the fuel
crossfeed dump shutoff system became inoperative, and fuel was dumped
below the minimum allowable level. The commenters point out that the
event that prompted the issuance of that AD occurred on a Model MD-11
airplane, not a Model DC-10 series airplane. Because the design of the
fuel shutoff system of the Model DC-10 is similar to that of the Model
MD-11, the FAA concluded that the potential unsafe condition could
exist with regard to those airplanes; however, there was no service
history relevant to the Model DC-10.
Second, the commenters indicate that the proposed modification of
the fuel crossfeed dump shutoff system, which is described in McDonnell
Douglas DC-10 Service Bulletin 28-208, would do nothing more than add a
third level of redundancy to the crossfeed low level shutoff relay. In
fact, the manufacturer, in its comments to the proposal, calls this
modification merely ``a design enhancement'' to the automatic shut-off
features of the fuel dump system; the manufacturer does not consider
that an AD to mandate the modification is justified.
Third, the commenters consider that the Model DC-10 already has
adequate redundancy present by means of a third crew member (the flight
engineer), who has specific required duties to monitor fuel quantity
and associated fault indication systems during fuel dump operations.
The commenters consider that, with this additional crew member in the
cockpit directly managing the fuel dumping process, there is adequate
protection against dumping fuel below the minimum level. The commenters
also point out that, even though AD 94-07-07 [amendment 39-8865 (59 FR
15853, April 5, 1994)] mandated a similar modification of the Model MD-
11, those airplanes are operated by a two-man crew and, therefore, do
not have the same level of redundancy as the Model DC-10 with its
three-man crew.
For these reasons, the commenters contend that mandatory
modification in accordance with the requirements of the proposed rule
is not justified for Model DC-10 series airplanes.
Upon further consideration, the FAA concurs. The FAA has reviewed
the service history of Model DC-10 series airplanes with regard to the
fuel crossfeed dump shutoff system and finds that the unsafe condition
previously specified in the proposal is addressed adequately by:
1. the current AFM revisions required by AD 92-22-06, and
2. the flight engineer having specific duties associated with
monitoring minimum fuel during dumping operations.
Accordingly, the proposed rule is hereby withdrawn.
Withdrawal of this notice of proposed rulemaking constitutes only
such action, and does not preclude the agency from issuing another
notice in the future, nor does it commit the agency to any course of
action in the future.
Since this action only withdraws a notice of proposed rulemaking,
it is neither a proposed nor a final rule and therefore, is not covered
under Executive Order 12866, the Regulatory Flexibility Act, or DOT
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979).
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
[[Page 7925]]
The Withdrawal
Accordingly, the notice of proposed rulemaking, Docket 94-NM-70-AD,
published in the Federal Register on July 27, 1994 (59 FR 38141), is
withdrawn.
Issued in Renton, Washington, on February 6, 1995.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-3358 Filed 2-9-95; 8:45 am]
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