HNA-HNA-23-2394-01C
TAT带引气管路的构型，气源来自于APU引气，目的是在地面或者慢速滑行状态下的时候，能通过排气形成的负压，主动吸气，使该阶段的探测温度更加准确。
当使用在不带引气管路上的时候，需要将管路封堵，不然电子舱的气会从管路漏出去。实测，对增压影响不大。
波音答复CAP堵盖是否安装都不影响TAT探头的功能，但这个堵盖起到密封的功能，阻断飞机内外部气流的连通。如果没有件号为BACC14AD04J的堵盖，也可以安装类似的阻挡气流的盖子或密封件作为临时措施。
The ejector fitting of an aspirated TAT probe normally connected to an aspirated aircraft’s pneumatic line to receive engine bleed air, this circulates air through the TAT probe even at low/no airspeed on ground and allows aspirated configurations to receive accurate temperature information on ground. As such a plug should not be installed for aspirated aircraft and instead the ejector fitting should be connected to the pneumatic line.
For non-aspirated aircraft there is no pneumatic line, so to protect the fitting a cap is installed. Whether the cap is present does not impact the function of the TAT probe, but does provide a seal blocking airflow from outside the aircraft. Boeing cannot provide guidance for AoGs in the future as circumstances will vary, but similar caps or seals to prevent airflow would provide similar function.
