# Airworthiness Directives; Bombardier Model DHC-7 Series Airplanes
> **Rule** · Final rule. · Published 1999-02-04 · Effective 1999-03-11 · 64 FR 5587
## Document
- **Document number:** 99-2497
- **Category:** airworthiness
- **Manufacturer:** Bombardier Model DHC-7 Series
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 64 FR 5587
- **Publication date:** 1999-02-04
- **Effective date:** 1999-03-11
- **FAA docket:** Docket No. 98-NM-295-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to all Bombardier Model DHC-7 series airplanes, that requires removal of all attachment bolts and pre-load indicating (PLI) washers of the wing-to-fuselage attachment fittings; a one-time visual inspection to detect corrosion of each attachment bolt; and installation of new attachment bolts and PLI washers of the wing-to- fuselage attachment fittings. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent failure of the attachment bolts of the wing-to-fuselage attachment fittings due to stress corrosion cracking, which could result in reduced structural integrity of the airplane.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/02/04/99-2497/airworthiness-directives-bombardier-model-dhc-7-series-airplanes)
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