Airworthiness Directives; McDonnell Douglas Model MD-11 and MD- 11F Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-NM-179-AD; Amendment 39-8865; AD 94-07-07]

Airworthiness Directives; McDonnell Douglas Model MD-11 and MD-

11F Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to certain McDonnell Douglas Model MD-11 and MD-11F

airplanes, that requires modification of the fuel crossfeed low level

dump system shutoff. This amendment is prompted by an FAA determination

that, in the event of a failure of the number 2 bus tie relay and the

subsequent loss of the number 2 electrical power source, an all-engine

flameout event could occur due to fuel starvation during or shortly

after a fuel dumping operation. The actions specified by this AD are

intended to prevent loss of the fuel dump system shutoff due to a

failure of the number 2 DC bus electrical relay and the subsequent loss

of the number 2 electrical power source.

DATES: Effective May 5, 1994.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of May 5, 1994.

ADDRESSES: The service information referenced in this AD may be

obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach,

California 90801-1771, Attention: Business Unit Manager, Technical

Administrative Support, Department L51, M.C. 2-98. This information may

be examined at the Federal Aviation Administration (FAA), Transport

Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton,

Washington; or at FAA, Transport Airplane Directorate, Los Angeles

Aircraft Certification Office, 3229 East Spring Street, Long Beach,

California; or at the Office of the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Raymond Vakili, Aerospace Engineer,

Propulsion Branch, ANM-141L, FAA, Transport Airplane Directorate, Los

Angeles Aircraft Certification Office, 3229 East Spring Street, Long

Beach, California 90806-2425; telephone (310) 988-5262; fax (310) 988-

5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations to include an airworthiness directive (AD), that

is applicable to certain McDonnell Douglas Model MD-11 and MD-11F

airplanes, was published in the Federal Register on December 9, 1993

(58 FR 64708). That action proposed to require modification of the fuel

crossfeed low level dump system shutoff.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

Several commenters support the proposed rule.

One commenter requests that the proposed compliance time of 15

months to modify the fuel crossfeed low level dump system shutoff be

extended to 24 months to coincide with regularly scheduled ``C''

checks. The commenter states that a compliance time of 24 months would

allow operators some latitude to schedule the accomplishment of this

modification. The FAA concurs with the commenter's request to extend

the compliance time for the modification requirement so that the

modification can be performed at a maintenance base during regularly

scheduled maintenance where special equipment and trained maintenance

personnel will be available if necessary. Extending the compliance time

by 9 additional months will not adversely affect safety since the

interim procedures [via a revision to the Airplane Flight Manual (AFM)]

required by AD 92-22-06, Amendment 39-8392 (57 FR 47570, October 19,

1992) will detect electrical malfunctions that may render the automatic

fuel dump termination feature inoperative. Therefore, paragraph (a) of

the final rule has been revised to specify a compliance time of 24

months.

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule with the change previously

described. The FAA has determined that this change will neither

increase the economic burden on any operator nor increase the scope of

the AD.

There are approximately 98 McDonnell Douglas Model MD-11 and MD-11F

airplanes of the affected design in the worldwide fleet. The FAA

estimates that 43 airplanes of U.S. registry will be affected by this

AD, that it will take approximately 6 work hours per airplane to

accomplish the required actions, and that the average labor rate is $55

per work hour. Required parts will cost approximately $5,688 per

airplane. Based on these figures, the total cost impact of the AD on

U.S. operators is estimated to be $258,774, or $6,018 per airplane.

The total cost impact figure discussed above is based on

assumptions that no operator has yet accomplished any of the

requirements of this AD action, and that no operator would accomplish

those actions in the future if this AD were not adopted.

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.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it 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 14 CFR part

39 of the Federal Aviation Regulations 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:

94-07-07 McDonnell Douglas: Amendment 39-8865. Docket 93-NM-179-AD.

Applicability: Model MD-11 and MD-11F airplanes having

manufacturer's fuselage numbers 447 through 544 inclusive,

certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent loss of the fuel dump system shutoff due to a failure

of the number 2 DC bus electrical relay and the subsequent loss of

the number 2 electrical power source, accomplish the following:

(a) Within 24 months after the effective date of this AD, modify

the fuel crossfeed low level dump system shutoff in accordance with

McDonnell Douglas MD-11 Service Bulletin 28-48, dated September 30,

1993. Accomplishment of this modification constitutes terminating

action for the revisions to the Airplane Flight Manual (AFM)

required by paragraph (a) of AD 92-22-06, Amendment 39-8392.

(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

Maintenance Inspector, who may add comments and then send it to the

Manager, Los Angeles ACO.

Note: 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

Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the

airplane to a location where the requirements of this AD can be

accomplished.

(d) The modification shall be done in accordance with McDonnell

Douglas MD-11 Service Bulletin 28-48, dated September 30, 1993. 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, Department 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, 3229 East Spring Street, Long Beach,

California; or at the Office of the Federal Register, 800 North

Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on May 5, 1994.

Issued in Renton, Washington, on March 23, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-7318 Filed 4-4-94; 8:45 am]

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