# Airworthiness Directives; Agusta S.p.A. Model AB 412 Helicopters
> **Rule** · Final rule; request for comments. · Published 1998-04-01 · Effective 1998-04-16 · 63 FR 15753
## Document
- **Document number:** 98-8464
- **Category:** airworthiness
- **Manufacturer:** Agusta S.p.A. Model AB 412
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 63 FR 15753
- **Publication date:** 1998-04-01
- **Effective date:** 1998-04-16
- **FAA docket:** Docket No. 97-SW-63-AD
## Abstract

This amendment adopts a new airworthiness directive (AD) that is applicable to Agusta S.p.A. (Agusta) Model AB 412 helicopters. This action requires an inspection of the tail rotor blades for debond voids and replacement, if necessary. This amendment is prompted by the loss of a tail rotor blade tip on a tail rotor blade while the helicopter was in service. This condition, if not corrected, could result in increased vibration levels, damage to the tail rotor drive system or tail rotor assembly, and subsequent loss of control of the helicopter.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1998/04/01/98-8464/airworthiness-directives-agusta-spa-model-ab-412-helicopters)
---
*MORVS · CC0 1.0*