# Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and PC-12/45 Airplanes
> **Rule** · Final rule. · Published 1999-09-17 · Effective 1999-11-08 · 64 FR 50439
## Document
- **Document number:** 99-24088
- **Category:** airworthiness
- **Manufacturer:** Pilatus
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 64 FR 50439
- **Publication date:** 1999-09-17
- **Effective date:** 1999-11-08
- **FAA docket:** Docket No. 98-CE-119-AD
## Abstract

This amendment adopts a new airworthiness directive (AD) that applies to certain Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC- 12/45 airplanes. This AD requires inspecting all flap actuator internal gear systems to assure that correct end-play and backlash measurements exist, and accomplishing any corrective adjustments as necessary. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified by this AD are intended to prevent premature wear of the internal gear system caused by excessive backlash in the flight control flap actuators, which could eventually result in loss of actuator output with possible reduced or loss of airplane control.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/09/17/99-24088/airworthiness-directives-pilatus-aircraft-ltd-models-pc-12-and-pc-1245-airplanes)
---
*MORVS · CC0 1.0*