# Airworthiness Directives; Boeing Model 737-600, -700, and -800 Series Airplanes
> **Rule** · Final rule. · Published 1999-02-11 · Effective 1999-03-18 · 64 FR 6791
## Document
- **Document number:** 99-3188
- **Category:** airworthiness
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 64 FR 6791
- **Publication date:** 1999-02-11
- **Effective date:** 1999-03-18
- **FAA docket:** Docket No. 98-NM-258-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737-600, -700, and -800 series airplanes, that requires repetitive inspections to detect damage of the aft strut insulation blanket. This AD also requires eventual replacement of the insulation blankets with new, improved blankets, which constitutes terminating action for the requirements of this AD. This amendment is prompted by reports of damaged aft strut insulation blankets. The actions specified by this AD are intended to prevent such damage, which could result in exposure of the lower surface of the strut to extreme high temperatures, consequent creation of a source of fuel ignition, and increased risk of a fuel tank explosion and fire.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/02/11/99-3188/airworthiness-directives-boeing-model-737-600--700-and--800-series-airplanes)
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