# Proposed AD 99-NM-372-AD: Raytheon (Beech) Model 400A and 400T Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2000-09-12
- Action: Notice of proposed rulemaking (NPRM).
- Published: January 12, 2000, 65 FR 1836
- Comments due: February 28, 2000
- Became: [AD 2000-09-12](https://openairdocs.org/ad/2000-09-12)
- Docket: 99-NM-372-AD
- FR document: 00-599
- Official PDF: https://openairdocs.org/files/sha256/67/d3/67d34cbbd7ebb1965431f57cad1b8afec1f5c0072a8bc2730ada4065b32ad22e (from https://www.govinfo.gov/content/pkg/FR-2000-01-12/pdf/00-599.pdf)
- Federal Register: https://www.federalregister.gov/documents/2000/01/12/00-599/airworthiness-directives-raytheon-beech-model-400a-and-400t-series-airplanes
- Page: https://openairdocs.org/proposed/99-NM-372-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Raytheon (Beech) Model 400A and 400T series airplanes. This proposal would require replacement of temperature switch assemblies of the wing ice protection system with new, improved parts. This proposal is prompted by reports of electrical continuity problems with solder joints on the temperature switches of the wing ice protection system. The actions specified by the proposed AD are intended to prevent detachment or breakage of wires in the temperature switch assemblies of the wing ice protection system. Such detachment or breakage of wires could result in the flightcrew not being advised of an over-temperature situation on the leading edge of the wing, which could result in structural damage to the wing.

## Notices in this docket

- Jan 12, 2000: Notice of proposed rulemaking (NPRM). (first notice), FR document 00-599, comments due Feb 28, 2000 (https://www.federalregister.gov/documents/2000/01/12/00-599/airworthiness-directives-raytheon-beech-model-400a-and-400t-series-airplanes)

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