# Airworthiness Directives; Lockheed Model L-1011-385 Series Airplanes
> **Rule** · Final rule. · Published 1999-04-26 · Effective 1999-06-01 · 64 FR 20144
## Document
- **Document number:** 99-10183
- **Category:** airworthiness
- **Manufacturer:** Lockheed Model L-1011-385 Series
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 64 FR 20144
- **Publication date:** 1999-04-26
- **Effective date:** 1999-06-01
- **FAA docket:** Docket No. 98-NM-199-AD
## Abstract

This amendment supersedes an existing airworthiness directive (AD), applicable to all Lockheed Model L-1011-385 series airplanes, that currently requires inspections to detect cracking of fuselage station (FS) 983 main frame (left and right sides), and repair, if necessary. That AD was prompted by reports of cracks found in the left and right sides of the FS 983 main frame, below the level of the cabin floor. This amendment adds a new requirement to review the airplane maintenance records to determine if a crack within the FS 983 main frame web was detected previously, and if repair of any such crack was deferred; and repetitive inspections, if necessary, until accomplishment of a repair. This amendment also adds terminating action for the repetitive inspections. The actions specified by this AD are intended to prevent cracking of the FS 983 frame, which could result in reduced structural integrity of the fuselage.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/04/26/99-10183/airworthiness-directives-lockheed-model-l-1011-385-series-airplanes)
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