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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-35-AD]

RIN 2120-AA64

Airworthiness Directives; Lockheed Model L-1011-385 Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to all Lockheed Model L-1011-385

series airplanes. This proposal would require repetitive inspections to

detect corrosion or fatigue cracking of certain structural elements of

the airplane; corrective action, if necessary; and incorporation of

certain structural modifications. This proposal is prompted by new

recommendations related to incidents of fatigue cracking and corrosion

in transport category airplanes that are approaching or have exceeded

their economic design goal. The actions specified by the proposed AD

are intended to prevent corrosion or fatigue cracking of certain

structural elements, which could result in reduced structural integrity

of the airplane.

DATES: Comments must be received by August 9, 1999.

[[Page 34171]]

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 98-NM-35-AD, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056. Comments may be inspected at this location

between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal

holidays.

The service information referenced in the proposed rule may be

obtained from Lockheed Martin Aircraft & Logistics Center, 120 Orion

Street, Greenville, South Carolina 29605. This information may be

examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,

SW., Renton, Washington; or at the FAA, Small Airplane Directorate,

Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix

Boulevard, suite 450, Atlanta, Georgia.

FOR FURTHER INFORMATION CONTACT: Thomas Peters, Aerospace Engineer,

Systems and Flight Test Branch, ACE-116A, FAA, Small Airplane

Directorate, Atlanta Aircraft Certification Office, One Crown Center,

1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone

(770) 703-6063; fax (770) 703-6097.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the

proposed rule by submitting such written data, views, or arguments as

they may desire. Communications shall identify the Rules Docket number

and be submitted in triplicate to the address specified above. All

communications received on or before the closing date for comments,

specified above, will be considered before taking action on the

proposed rule. The proposals contained in this notice may be changed in

light of the comments received.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the proposed rule. All

comments submitted will be available, both before and after the closing

date for comments, in the Rules Docket for examination by interested

persons. A report summarizing each FAA-public contact concerned with

the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this notice must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket Number 98-NM-35-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request

to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules

Docket No. 98-NM-35-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

In April 1988, a transport category airplane managed to land after

tiny cracks in rivet holes in the upper fuselage linked together,

causing structural failure and explosive decompression. An 18-foot

section ripped from the fuselage. This accident focused greater

attention on the problem of aging aircraft.

Subsequently, in June 1988, the FAA sponsored a conference on aging

airplane issues, which was attended by representatives of the aviation

industry from around the world. It became obvious that, because of the

tremendous increase in air travel, the relatively slow pace of new

airplane production, and the apparent economic feasibility of operating

older technology airplanes rather than retiring them, increased

attention needed to be focused on this aging fleet and maintaining its

continued operational safety.

The Air Transport Association (ATA) of America and the Aerospace

Industries Association (AIA) of America committed to identifying and

implementing procedures to ensure continuing structural airworthiness

of aging transport category airplanes. The Airworthiness Assurance

Working Group (AAWG), with representatives from the aircraft operators,

manufacturers, regulatory authorities, and other aviation

representatives, was originally established in August 1988. The

objective of the AAWG was to sponsor ``Task Groups'' to:

1. Select service bulletins, applicable to each airplane model in

the transport fleet, to be recommended for mandatory modification of

aging airplanes,

2. Develop corrosion-directed inspections and prevention programs,

3. Review the adequacy of each operator's structural maintenance

program,

4. Review and update the Supplemental Structural Inspection

Documents (SSID),

5. Assess repair quality.

The Structures Task Group (STG) assigned to review the Lockheed

Model L-1011-385 series airplanes was formed in 1988, and included

operators of Model L-1011-385 series airplanes, Lockheed, the FAA, and

observers from regulatory agencies. Certain recommendations made by the

STG (pursuant to Item 1., described previously) are contained in

Lockheed Service Bulletin 093-51-035, Revision 1, dated December 16,

1991. The FAA previously issued AD 94-05-01, amendment 39-8839 (59 FR

10275, March 4, 1994), to require the structural inspections and the

modifications recommended in that document.

Since the issuance of that AD, the STG has recommended

accomplishment of certain other structural inspections to detect

corrosion or fatigue cracking of certain structural elements of the

airplane, and incorporation of certain structural modifications.

Corrosion or fatigue cracking of certain structural elements, if not

detected and corrected, could result in reduced structural integrity of

the airplane.

Explanation of Relevant Service Information

Lockheed has issued Service Bulletin 093-51-040, Revision 1, dated

October 1, 1997 (hereinafter referred to as the ``Collector Service

Bulletin''). The Collector Service Bulletin describes certain

repetitive inspections to detect corrosion or fatigue cracking of

certain structural elements of the airplane, including the area around

the two aft passengers doors and the fuselage-to-underwing longeron

area at butt line 94.5. The Collector Service Bulletin also describes

structural modifications of various elements of the airplane that have

been recommended by the STG, including modification of the retract

actuators of the main landing gear, modification of the bulkhead at

fuselage station 1363, and replacement of the wing rear spar web (for

Model L-1011-385-3 series airplanes). The Collector Service Bulletin

also references appropriate sources of accomplishment instructions for

the structural inspections and modifications.

The FAA has reviewed and approved the Collector Service Bulletin.

Accomplishment of the actions specified in the Collector Service

Bulletin is intended to adequately address the identified unsafe

condition.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to

exist or develop on other products of this same type design, the

proposed AD would require accomplishment of the actions specified in

the service bulletin described previously, except as discussed below.

[[Page 34172]]

Other Relevant Rulemaking

The FAA previously has issued AD 98-10-14, amendment 39-10526 (63

FR 26966, May 15, 1998), applicable to all Lockheed Model L-1011-385

series airplanes, to require various inspections to detect cracking of

certain areas of the rear spar caps, web, skin, and certain fastener

holes; and follow-on actions. Accomplishment of the terminating

modification listed in Lockheed Service Bulletin 093-57-215 (referenced

in Table II of the Collector Service Bulletin), as required by

paragraph (e) of this proposed AD; would constitute terminating action

for the inspection requirements of AD 98-10-14 for the affected

airplanes.

Differences Between This Proposed Rule and the Service Bulletin

Operators should note that Table II of the Collector Service

Bulletin references structural inspections specified in Lockheed

Service Bulletins 093-53-268, Revision 1, dated July 2, 1996, and 093-

53-272, Revision 1, dated March 17, 1997. However, the FAA previously

issued AD 99-08-20, amendment 39-11128 (64 FR 18324, April 14, 1999),

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

require the structural inspections specified in Lockheed Service

Bulletins 093-53-268, Revision 1, and 093-53-272, dated November 12,

1996. The FAA has determined that the procedures described in Lockheed

Service Bulletin 093-53-272, Revision 1, are substantially similar to

those specified in the original issue of that service bulletin.

Therefore, paragraph (b) of this proposed AD specifies that structural

inspections in accordance with Lockheed Service Bulletins 093-53-268,

Revision 1, and 093-53-272, Revision 1, would not be required by this

AD.

Operators also should note that the Collector Service Bulletin

specifies that installation of the modifications in Lockheed Service

Bulletins 093-53-268, Revision 1, and 093-53-272, terminates the

inspections specified in Lockheed Service Bulletins 093-53-268,

Revision 1, and 093-53-272, Revision 1. However, this proposed AD

specifies that installation of those modifications does not constitute

terminating action for the subject inspections. AD 99-08-20 does not

provide for termination of the inspections by installation of the

modifications, though that AD does specify that inspections may be

deferred for 18,000 landings, if modifications in accordance with

Lockheed Service Bulletins 093-53-268, Revision 1, and 093-53-272 are

accomplished.

Operators also should note that, for airplanes that have exceeded

the later of the inspection thresholds specified in Lockheed Service

Bulletin 093-57-203, Revision 5, dated April 22, 1996, the Collector

Service Bulletin specifies a grace period of 5 years or 5,000 flight

cycles after April 11, 1996 (the initial release date of Lockheed

Service Bulletin 093-57-215), for accomplishment of the terminating

modification described in Lockheed Service Bulletin 093-57-215, dated

April 11, 1996. This proposed rule specifies a grace period for that

modification of 2 years or 2,000 flight cycles after the effective date

of this AD. The proposed grace period was developed by taking into

account the manufacturer's recommended grace period of five years after

April 11, 1996, as well as the length of time that is normally required

for the rulemaking process to be completed. In consideration of both of

these factors, the FAA finds that a grace period of 2 years or 2,000

flight cycles after the effective date of the AD is adequate to ensure

the continued safety of the transport airplane fleet. The FAA also

finds that such a grace period will provide operators with slightly

more time than what was specified in the Collector Service Bulletin to

accomplish the terminating modification.

Cost Impact

There are approximately 214 airplanes of the affected design in the

worldwide fleet. The FAA estimates that 107 airplanes of U.S. registry

would be affected by this proposed AD.

It would take approximately 315 work hours per airplane to

accomplish the proposed inspections, at an average labor rate of $60

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

inspections proposed by this AD on U.S. operators is estimated to be

$2,022,300, or $18,900 per airplane, per inspection cycle.

It would take approximately 3,385 work hours per airplane to

accomplish the proposed modifications, at an average labor rate of $60

per work hour. Required parts would cost approximately $242,000 per

airplane. Based on these figures, the cost impact of the modifications

proposed by this AD on U.S. operators is estimated to be $47,625,700,

or $445,100 per airplane.

The cost impact figures discussed above are based on assumptions

that no operator has yet accomplished any of the proposed requirements

of this AD action, and that no operator would accomplish those actions

in the future if this AD were not adopted.

Regulatory Impact

The regulations proposed herein would 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

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this proposed

regulation (1) is not a ``significant regulatory action'' under

Executive Order 12866; (2) is not a ``significant rule'' under the DOT

Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);

and (3) if promulgated, 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 copy of the draft

regulatory evaluation prepared for this action is contained in the

Rules Docket. A copy of it may be obtained by contacting 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.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration proposes to amend

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. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

Lockheed: Docket 98-NM-35-AD.

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

certificated in any category.

Note 1: This AD applies to each airplane identified in the

preceding applicability provision, regardless of whether it has been

modified, altered, or repaired in the area subject to the

requirements of this AD. For airplanes that have been modified,

altered, or repaired so that the performance of the requirements of

this AD is affected, the owner/operator must request approval for an

alternative method of compliance in accordance with paragraph (f) of

this AD. The request should include an assessment of the

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effect of the modification, alteration, or repair on the unsafe

condition addressed by this AD; and, if the unsafe condition has not

been eliminated, the request should include specific proposed

actions to address it.

Compliance: Required as indicated, unless accomplished

previously.

To prevent corrosion or fatigue cracking of certain structural

elements, which could result in reduced structural integrity of the

airplane, accomplish the following:

Inspections

(a) Except as provided by paragraph (b) of this AD, perform

structural inspections to detect corrosion or fatigue cracking of

certain structural elements of the airplane, in accordance with the

applicable service bulletins listed under ``Service Bulletin Number,

Revision, and Date'' in Tables I and II of Lockheed Service Bulletin

093-51-040, Revision 1, dated October 1, 1997. Perform the initial

inspections at the later of the times specified in paragraphs (a)(1)

and (a)(2) of this AD. Thereafter, repeat each inspection at an

interval not to exceed that specified in the applicable service

bulletin.

(1) Prior to the threshold specified in the individual service

bulletin listed in Table I or II of Lockheed Service Bulletin 093-

51-040, Revision 1, as applicable.

(2) Within one repetitive interval after the effective date of

this AD, as specified in the individual service bulletin listed in

Table I or II of Lockheed Service Bulletin 093-51-040, Revision 1,

as applicable.

(b) The structural inspections specified in Lockheed Service

Bulletins 093-53-268, Revision 1, dated July 2, 1996, and 093-53-

272, Revision 1, dated March 17, 1997; as listed in Table II of

Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1,

1997; are not required by this AD. The inspections specified in

these service bulletins are required by AD 99-08-20, amendment 39-

11128.

Corrective Action

(c) If any cracking is detected during any inspection required

by paragraph (a) of this AD, prior to further flight, accomplish the

actions specified in paragraph (c)(1), (c)(2), (c)(3), or (c)(4) of

this AD.

(1) Repair in accordance with the applicable service bulletin

referenced in Table I or II of Lockheed Service Bulletin 093-51-040,

Revision 1, dated October 1, 1997.

(2) Repair in accordance with the applicable section of the

Lockheed L-1011 Structural Repair Manual.

(3) Accomplish the terminating modification in accordance with

the applicable service bulletin referenced in Table I or II of

Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1,

1997.

(4) Repair in accordance with a method approved by the Manager,

Atlanta Aircraft Certification Office (ACO), FAA, Small Airplane

Directorate.

Terminating Action

(d) Install the terminating modification referenced in each

service bulletin listed in Table II of Lockheed Service Bulletin

093-51-040, Revision 1, dated October 1, 1997; in accordance with

the applicable service bulletin listed under ``Service Bulletin

Number, Revision, and Date'' in Table II of Lockheed Service

Bulletin 093-51-040, Revision 1. Except as provided by paragraph (e)

of this AD, install each modification at the later of the times

specified in paragraphs (d)(1) and (d)(2) of this AD. Such

installation constitutes terminating action for the applicable

structural inspection required by paragraph (a) of this AD.

Note 2: Installation of the terminating modifications specified

in Lockheed Service Bulletin 093-53-268, Revision 1, dated July 2,

1996, and Lockheed Service Bulletin 093-53-272, dated November 12,

1996, does not constitute terminating action for the repetitive

inspection requirements of AD 99-08-20, amendment 39-11128.

(1) Prior to the threshold specified in the applicable service

bulletin listed in Table II of Lockheed Service Bulletin 093-51-040,

Revision 1.

(2) Within 5 years or 5,000 flight cycles after the effective

date of this AD, whichever occurs first.

(e) At the later of the times specified in paragraphs (e)(1) and

(e)(2) of this AD: Install the terminating modification listed in

Lockheed Service Bulletin 093-57-215, as referenced in Table II of

Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1,

1997. Such installation constitutes terminating action for the

inspections required by AD 98-10-14, amendment 39-10526.

(1) Prior to the threshold specified in Lockheed Service

Bulletin 093-57-203, Revision 5, dated April 22, 1996.

(2) Within 2 years or 2,000 flight cycles after the effective

date of this AD, whichever occurs first.

Alternative Methods of Compliance

(f) 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 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 3: Information concerning the existence of approved

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

obtained from the Atlanta ACO.

Special Flight Permits

(g) Special flight permits may be issued in accordance with

sections 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.

Issued in Renton, Washington, on June 18, 1999.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-16157 Filed 6-24-99; 8:45 am]

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