立即注册 登录
机务在线 返回首页

ryn_82的个人空间 https://www.airacm.com/?55843 [收藏] [复制] [RSS]

日志

APU 关车疑问HONEYWELL回复

已有 511 次阅读2013-4-23 09:23 |个人分类:发动机

[size=3]The 60 second timer is started when the BAV closed signal is received and the APU will not shut down until the timer has completed it countdown (except for protective shutdowns). This means that when the APU M/S is set to OFF:
1.     If the BAV is OPEN, it will be as described in the training notes i.e. you will get a full 60 second cool-down.
2.     If the BAV is CLOSED, and has been closed for >60 seconds, the APU will shutdown straight away
3.     If the BAV is CLOSED but has been closed for <60 seconds, the 60 second timer will complete its full countdown before the APU shuts down i.e. if the BAV has been closed for 30 seconds when you set the M/S to OFF, the APU will not shut down for another 30 seconds
As explained in the notes, the reason for the cool-down is to lower and stabilize the internal core temperature to help prevent coking of the fuel nozzles, turbine bearing seal and the cool down timer is there to achieve this. Making sure this happens is obviously beneficial and the BAV closed for greater than 60 seconds isn't going to do any harm but we are not the agency that gives on-wing or operational recommendations, that is Airframer. Having the APU sitting running, but doing nothing, is just using fuel, so as long as the operator is using the correct published shut down procedures they should be OK. What operators need to avoid is bypassing the cool-down by switching off the aircraft batteries to cause an immediate shut down.[/size]

路过

雷人

握手

鲜花

鸡蛋

全部作者的其他最新日志

评论 (0 个评论)

facelist

您需要登录后才可以评论 登录 | 立即注册

返回顶部