AD 94-03-09

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AD Number:
94-03-09
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Lockheed Model L-1011-385 Series Airplanes
Subject:
Flap Vane Lugs
Status:
Current
Citation:
Federal Register: February 17, 1993 (Volume 59, Number 33)
Citation Publish Date:
02/17/1993
Effective Date:
03/21/1994
Make:
Lockheed Martin Corporation
Model:
L-1011-385-1 | L-1011-385-1-14 | L-1011-385-1-15 | L-1011-385-3
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 94-03-09
CITATION:   [Federal Register: February 17, 1993 (Volume 59, Number 33)]

PAGE NUMBER:   [Page 7903]

DOCKET NUMBER:   Unknown

AMENDMENT:   39-8816

AD NUMBER:   94-03-09

SUBJECT HEADING:   Airworthiness Directives; Lockheed Model L-1011-385 Series Airplanes

ACTION:   Final Rule

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.

§ 39.13 - [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

REGULATORY TEXT:  
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.

FOOTER: