# Airworthiness Directives; Gulfstream American (Frakes Aviation) Model G-73 (Mallard) and G-73T Series Airplanes
> **Rule** · Final rule. · Published 1999-11-22 · Effective 1999-12-27 · 64 FR 63576
## Document
- **Document number:** 99-30133
- **Category:** airworthiness
- **Manufacturer:** Gulfstream American (Frakes Aviation) Model G-73 (Mallard) and G-73T Series
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 64 FR 63576
- **Publication date:** 1999-11-22
- **Effective date:** 1999-12-27
- **FAA docket:** Docket No. 99-NM-141-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to certain Gulfstream American (Frakes Aviation) Model G-73 (Mallard) and G-73T series airplanes, that requires revising the Airplane Flight Manual (AFM) to include requirements for activation of the airframe pneumatic deicing boots. This amendment is prompted by reports of inflight incidents and an accident that occurred in icing conditions where the airframe pneumatic deicing boots were not activated. The actions specified by this AD are intended to ensure that flightcrews activate the pneumatic wing and tail deicing boots at the first signs of ice accumulation. This action will prevent reduced controllability of the aircraft due to adverse aerodynamic effects of ice adhering to the airplane prior to the first deicing cycle.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/11/22/99-30133/airworthiness-directives-gulfstream-american-frakes-aviation-model-g-73-mallard-and-g-73t-series)
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