Airworthiness Directives; McDonnell Douglas Model DC-10 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-22-AD; Amendment 39-9050; AD 94-22-01]

Airworthiness Directives; McDonnell Douglas Model DC-10 Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive

(AD), applicable to all McDonnell Douglas Model DC-10-10, -10F, -30,

and -30F series airplanes, that currently requires inspections to

detect ice or snow accumulation on top of the fuselage and in the inlet

of the number 2 engine, and removal of ice and snow accumulation. This

amendment adds certain airplanes to the applicability of the rule and

limits the inspection requirement to only a certain group of airplanes.

This amendment is prompted by the development of improved fan blades on

certain engines and the identification of additional airplanes that are

subject to the unsafe condition. The actions specified by this AD are

intended to minimize damage to the number 2 engine due to ingestion of

ice and snow.

EFFECTIVE DATE: November 28, 1994.

ADDRESSES: Information related to this rule may be examined at the

Federal Aviation Administration (FAA), Transport Airplane Directorate,

Rules Docket, 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.

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 (14 CFR part 39) by superseding AD 75-04-11,

amendment 39-2094, which is applicable to all McDonnell Douglas Model

DC-10-10, -10F, -30, and -30F series airplanes, was published in the

Federal Register on July 18, 1994 (59 FR 36375). The action proposed to

supersede AD 75-04-11, which currently requires inspections to detect

ice and snow accumulation on top of the fuselage and in the inlet of

the number 2 engine, and removal of ice and snow. The action proposed

to add Model DC-10-15 series airplanes to the applicability of the

rule, and to limit the inspection requirement to only a certain group

of airplanes.

Interested persons have been afforded an opportunity to participate

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

the single comment received.

The commenter supports the proposed rule.

After careful review of the available data, including the comment

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

interest require the adoption of the rule as proposed.

There are approximately 379 McDonnell Douglas Model DC-10-10, -10F,

-30, -30F, and -15 series airplanes and Model KC-10A (military)

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

estimates that 226 airplanes of U.S. registry will be affected by this

AD. (Currently, there are no Model DC-10-15 series airplanes of U.S.

registry that will be affected by this AD.)

The inspections that were previously required by AD 75-04-11, and

retained in this AD take approximately 1 work hour per airplane to

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

per work hour. Based on these figures, the total cost impact of the

inspection requirement on U.S. operators is estimated to be $12,430, or

$55 per airplane, per inspection. This AD will only add the cost of

inspections for the operators of Model KC-10A (military) airplanes.

For operators of Model DC-10-10, -10F, -30, and -30F series

airplanes having all solid fan blades in the number 2 engine position,

the economic burden will be reduced since the previous requirement to

inspect these airplanes in accordance with the existing AD will be

eliminated by this AD. However, this does not relieve operators of the

responsibility to comply with the requirements of Secs. 91.527

(``Operating in icing conditions'') and 121.629 (``Operation in icing

conditions''--air carriers) of the Federal Aviation Regulations (14 CFR

91.527 and 121.629).

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, 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing amendment 39-2094, and by

adding a new airworthiness directive (AD), amendment 39-, to read as

follows:

94-22-01 McDonnell Douglas: Amendment 39-9050. Docket 94-NM-22-AD.

Supersedes AD 75-04-11, Amendment 39-2094.

Applicability: Model DC-10-10, -10F, -30, -30F, and -15 series

airplanes, and Model KC-10A (military) airplanes, on which the

number 2 engine is a General Electric Model CF6 series turbofan

engine having one or more gundrilled fan blades installed, including

but not limited to part numbers 9010M33 and 9137M39; certificated in

any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent possible damage to the number 2 engine due to

ingestion of ice and snow, accomplish the following:

(a) As of the effective date of this AD, prior to starting the

number 2 engine on any airplane that has been parked during icing

conditions (freezing rain, snow, sleet) for any period of time

during which ice or snow may have accumulated on the airplane in the

area of the number 2 engine, inspect to detect ice and snow

accumulation on top of the fuselage and in the inlet of the number 2

engine. If ice or snow accumulation is found, prior to further

flight, remove the ice or snow accumulation.

Note 1: Guidelines for inspection and safeguarding the aircraft

are contained in these documents:

Douglas All Operators Letter (AOL) 10-546, dated January 11, 1974

Douglas AOL 10-673, dated August 7, 1974

DC-10 Airplane Maintenance Manual, Chapter 12-31-01

(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 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

Secs. 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 November 28, 1994.

Issued in Renton, Washington, on October 13, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-25846 Filed 10-26-94; 8:45 am]

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