本文件已被宣布为“非现行”。因此，建议本文件不适用于新设计。“非现行”指的是那些以前被广泛引用的文件，并且在一些现有设计中可能会继续需要这些文件。本航空航天标准确立了主要用于涡轮驱动亚音速运输机的马赫数计仪表的基本最低安全性能标准，其运行可能会使仪表受到第3.3节规定的环境条件的影响。本航空航天标准涵盖直读式压力驱动型马赫数计。

This document has been declared “NONCURRENT”. It is recommended, therefore, that this document not be specified for new designs. “NONCURRENT” refers to those documents which have previously been widely referenced and may continue to be required on some existing designs.This Aerospace Standard establishes the essential minimum safe performance standards for mach meter instruments primarily for use with turbine powered subsonic transport aircraft, the operation of which may subject the instruments to the environmental conditions specified in Section 3.3. This Aerospace Standard covers the direct reading pressure actuated type mach meter.