OPT落地性能的Recommended Brake Cooling Time

大约一个月前,被别人问到OPT里计算出来的落地性能,有一个Recommended Brake Cooling Time,其中有Inflight的时间,好奇这个是在落地时提前放轮的冷却时间还是下一段起飞后的冷却时间?

我查询了一下Jet Transport Performance Methods当中有一段说道了“possible brake problems on short-haul operations短距离飞行对刹车的影响”:

Some operators may instruct their crews to leave the gear extended for a few minutes after each takeoff. Each of these will be helpful, and short-haul operators usually employ one or more of them to avoid fuse plug melting.

因此,OPT中的inflight cooling应该指的是在起飞之后,推迟收轮的时间。

然后在FPPM中有具体的时间图表:

在FPPM的说明部分描述为:

For normal operations most landings are at weights below the quick turnaround limit.通常情况下,落地重量都低于quick turnaround limit。
Application of there commended cooling procedures shown will avoid brake over heat and fuse plug problems that could result from repeated landings at short time intervals or a reiected takeoff等待图标中的时间,可以避免在重复落地或中断起飞时造成热熔塞融化. The chart shows the brake energy perbrake added by a single stop. Total brake energy is assumed to be equally distributed among the operating brakes. Total brake energy is the sum of the residual energy from prevous stops plus the energy added.

当然,有人问,如果起飞时单发了,延迟收轮给刹车降温是不是影响起飞性能?当然在起飞单发后,还是按原来的程序收轮,起飞越障肯定比刹车超温来的重要。

inflight cooling是最有效的降温方法。

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原本我以为,我公司不可能运行short-haul航班,当时前几天的确被我们遇到一个案例。

我公司有一架飞机要试飞,试飞过程中,落地到停机位但不开舱门,机务做好检查后继续起飞试飞。这种情况,理论上是会出现刹车温度累积的情况。(只是理论上,因为试飞飞机很轻)