Airworthiness Directives; Lockheed Model L-1011-385 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-131-AD; Amendment 39-8816; AD 94-03-09]

Airworthiness Directives; Lockheed Model L-1011-385 Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

applicable to all Lockheed Model L-1011-385 series airplanes, that

requires inspection, modification, and replacement, if necessary, of

the flap vane lugs. This amendment is prompted by reports of failure of

flap vane lugs due to stress corrosion. The actions specified by this

AD are intended to prevent failure of the flap vane lugs, which could

lead to separation of flap vane from the airplane and cause injury to

people or damage to property on the ground.

DATES: Effective March 21, 1994.

The incorporation by reference of certain publications listed in

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

of March 21, 1994.

ADDRESSES: The service information referenced in this AD may be

obtained from Lockheed Western Export Company, Attn: Commercial and

Customer Support, Dept. 693, Zone 0755, 86 South Cobb Drive, Marietta,

Georgia 30063. This information may be examined at the Federal Aviation

Administration (FAA), Transport Airplane Directorate, Rules Docket,

1601 Lind Avenue SW., Renton, Washington; or at the FAA, Atlanta

Aircraft Certification Office, 1669 Phoenix Parkway, suite 210C,

Atlanta, Georgia; or at the Office of the Federal Register, 800 North

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

FOR FURTHER INFORMATION CONTACT: Thomas B. Peters, Aeronautical

Engineer, Flight Test Branch, Atlanta Aircraft Certification Office,

FAA, Small Airplane Directorate, 1669 Phoenix Parkway, suite 210C,

Atlanta, Georgia 30349; telephone (404) 991-3915; fax (404) 991-3606.

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

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

applicable to Lockheed Model L-1011-385 series airplanes was published

in the Federal Register on September 21, 1993 (58 FR 48984). That

action proposed to require inspection, modification, and replacement,

if necessary, of the flap vane lugs.

Interested persons have been afforded an opportunity to participate

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

the comments received.

Two commenters support the proposal.

Two commenters request that the compliance time for the inspection

of the flap vane lugs be extended from the proposed 1,800 flight hours

to at least 3,500 flight hours, in order to accommodate regularly

scheduled ``C'' check intervals for the majority of the affected fleet.

The commenters point out that, in the preamble to the proposal, the FAA

indicated that the intent of the specified compliance time of the rule

was to allow operators ``ample time for the inspection to be

accomplished coincidentally with scheduled major airplane inspection

and maintenance activities (i.e., `C' checks).'' The commenter states

that revising the compliance time to match the scheduled maintenance

interval will enable affected operators to procure adequate necessary

parts or manufacture them locally, thus minimizing costs and logistical

considerations. The FAA concurs that the compliance time should be

extended. Although the compliance time published in the notice was

``1,800 flight hours,'' the intended compliance time was actually

``1,800 flight cycles.'' This latter figure was meant to translate to

approximately 3,600 flight hours, which is the average interval for

scheduled ``C'' checks within the affected fleet. The final rule has

been revised to specify a compliance time of 1,800 flight cycles.

One commenter requests that the proposal be revised to allow

repetitive inspections to be accomplished in accordance with part I

(``Preparation and Inspection'') of the service bulletin, rather than

the proposed one-time inspection and follow-on rework in accordance

with part II (``Vane Lug Rework for Lugs Without a Crack/Corrosion

Indication''). The commenter suggests that the rework procedures of

part II could serve as terminating action for the repetitive

inspections. This would allow operators that have inspected but not

reworked the lug bores more time to accomplish the rework. It would

also allow operators more flexibility in complying with the AD. The FAA

does not concur. The inspection procedure specified in part I of the

service bulletin and paragraph (a) of this AD is neither designed as

nor intended to be an interim or on-going inspection to detect cracking

or corrosion. The purpose of that inspection is only to determine the

scope of the rework of the lug bores that is necessary. As for

providing additional time for conducting the rework procedures, as

discussed previously, the final rule has been revised to specify a

longer compliance time than was proposed. This longer interval will

provide sufficient time for operators to perform both the one-time

inspection and the necessary rework within normal maintenance

schedules.

One commenter requests that the proposed rule be revised to provide

some flexibility in the use of materials for bushing fabrication. The

commenter notes that the Lockheed service bulletin referenced in the

notice calls out ``QQ-C-645, CQ-Alloy 642, Drawn Annealed and Cadmium

Plated'' material for such fabrication. However, the commenter stocks a

bushing material made of a different alloy, which it uses in its fleet

in flight control and landing gear applications. The commenter requests

to be permitted to use this different material rather than the material

specified in the service bulletin. The FAA does not concur. There

currently are no FAA-approved data that would allow for the use of the

commenter's specific alloy in a flap vane lug application. However,

under the provisions of paragraph (e) of this AD, the commenter may

submit a request to use this material as an alternative method of

compliance with the AD, provided that substantiating data are included

to demonstrate that this material will provide an acceptable level of

safety in this particular application.

This same commenter requests that the proposed rule be revised to

include a part-marking procedure different from that called out in the

referenced service bulletin. The procedure contained in the service

bulletin specifies that the letter ``A'' is to be added to the end of

the part number on each modified (reworked) vane fitting. The commenter

requests that the rule include an alternative procedure to permit

adding the letter ``A'' after the part number of the top assembly (the

complete vane assembly) instead. The commenter states that this

alternative procedure will simplify changes to its stock number

assignments under its parts tracking system. The FAA cannot

specifically concur with this request. The FAA does not consider that

the inclusion of such changes as the one requested is appropriate in

this AD. However, as stated previously, under the provisions of

paragraph (e) of this AD, the commenter may submit a request to use an

alternative marking procedure as an alternative method of compliance

with the AD.

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 241 Model L-1011-385 series airplanes of

the affected design in the worldwide fleet. The FAA estimates that 117

airplanes of U.S. registry will be affected by this AD, that it will

take approximately 96 work hours per airplane to accomplish the

required actions, and that the average labor rate is $55 per work hour.

On the basis of these figures, the total cost impact of the AD on U.S.

operators is estimated to be $617,760, or $5,280 per airplane. -

However, the FAA has been advised that 56 of the affected U.S.-

registered airplanes have been inspected in accordance with the

requirements of this AD. Therefore, the future economic cost impact of

this rule on U.S. operators is now only $322,080.

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:

94-03-09 Lockheed: Amendment 39-8816. Docket 93-NM-131-AD.

Applicability: All Model L-1011-385 series airplanes,

certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent failure of the flap vane lugs, which could ultimately

lead to separation of the flap vane from the airplane and pose a

danger to persons and property on the ground, accomplish the

following:

(a) Within 1,800 flight cycles after the effective date of this

AD, inspect the inboard and outboard lug of each flap vane to detect

cracks and corrosion, in accordance with Lockheed TriStar L-1011

Service Bulletin 093-57-199, Revision 1, dated May 5, 1993.

Note: Inspections and rework previously accomplished prior to

the effective date of this AD in accordance with the original issue

of Lockheed TriStar L-1011 Service Bulletin 093-57-199, dated

January 21, 1988, are considered in compliance with this paragraph

and do not need to be repeated.

(b) For any lug that shows no evidence of cracks or corrosion,

prior to further flight, rework the lug bore in accordance with part

II of the service bulletin.

(c) If any lug has corrosion or cracking that is within the

limits specified in the service bulletin, prior to further flight,

accomplish the rework procedures in accordance with Part III of the

service bulletin.

(d) If any lug has corrosion or cracking that exceeds the limits

specified in the service bulletin, prior to further flight, replace

the lug with a new or serviceable part in accordance with the

service bulletin.

(e) 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, Atlanta Aircraft Certification

Office (ACO). Operators shall submit their requests through an

appropriate FAA Principal Maintenance Inspector, who may add

comments and then send it to the Manager, Atlanta ACO.

Note: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Atlanta ACO.

(f) Special flight permits may be issued in accordance with FAR

21.197 and 21.199 to operate the airplane to a location where the

requirements of this AD can be accomplished.

(g) The inspection, rework, and replacement procedures shall be

done in accordance with Lockheed TriStar L-1011 Service Bulletin

093-57-199, Revision 1, dated May 5, 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 Lockheed Western Export Company, Attn: Commercial and

Customer Support, Dept. 693, Zone 0755, 86 South Cobb Drive,

Marietta, Georgia 30063. Copies may be inspected at the FAA,

Transport Airplane Directorate, 1601 Lind Avenue SW., Renton,

Washington; or at the FAA, Atlanta Aircraft Certification Office,

1669 Phoenix Parkway, suite 210C, Atlanta, Georgia; or at the Office

of the Federal Register, 800 North Capitol Street NW., suite 700,

Washington, DC.

(h) This amendment becomes effective on March 21, 1994.

Issued in Renton, Washington, on January 28, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-2411 Filed 2-16-94; 8:45 am]

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