# Proposed AD 99-NM-138-AD: Gulfstream Model G-159 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2000-10-11
- Action: Supplemental notice of proposed rulemaking; reopening of comment period.
- Published: November 18, 1999, 64 FR 62991
- Comments due: December 13, 1999
- Became: [AD 2000-10-11](https://openairdocs.org/ad/2000-10-11)
- Docket: 99-NM-138-AD
- FR document: 99-30149
- Official PDF: https://openairdocs.org/files/sha256/59/cb/59cb7ad413a17b789caaaddd1f95fb1887521f68e02eb271ed6c9a9d7f3b41f2 (from https://www.govinfo.gov/content/pkg/FR-1999-11-18/pdf/99-30149.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/11/18/99-30149/airworthiness-directives-gulfstream-model-g-159-series-airplanes
- Page: https://openairdocs.org/proposed/99-NM-138-AD

## Summary

This document revises an earlier proposed airworthiness directive (AD), applicable to certain Gulfstream Model G-159 series airplanes, that would have required revising the Airplane Flight Manual (AFM) to include requirements for activation of the airframe pneumatic deicing boots. That proposal was prompted by reports of inflight incidents and an accident that occurred in icing conditions where the airframe pneumatic deicing boots were not activated. This new action revises the proposed rule by adding an inspection to determine the type of pneumatic deicing boots, and requiring the AFM change only for those airplanes equipped with ``modern'' boots. The actions specified by this new proposed 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.

## Notices in this docket

- Jul 16, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-17543, comments due Aug 16, 1999 (https://www.federalregister.gov/documents/1999/07/16/99-17543/airworthiness-directives-gulfstream-aerospace-model-g-159-series-airplanes)
- Nov 18, 1999: Supplemental notice of proposed rulemaking; reopening of comment period., FR document 99-30149, comments due Dec 13, 1999 (https://www.federalregister.gov/documents/1999/11/18/99-30149/airworthiness-directives-gulfstream-model-g-159-series-airplanes)

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