PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Tech Log (https://www.pprune.org/tech-log-15/)
-   -   a reverse thrust q... (https://www.pprune.org/tech-log/570835-reverse-thrust-q.html)

D driver 19th November 2015 10:45

a reverse thrust q...
 
Once the blocker doors are fully deployed, with an increase in RPM, which of the following statements would be incorrect?
a. Forward thrust from the hot gases would increase.
b. Forward thrust from the hot gases would decrease.
c. Reverse thrust from the blocked air would increase.
d. TGT will increase.
marked answer B :eek: . I believe it should be a.

FE Hoppy 19th November 2015 11:01

b is the correct answer in most cases. Blocker doors in the question implies it is not a clam shell system so it's the bypass air that's reversed not the core air.

eckhard 19th November 2015 11:25

As Hoppy says:

With blocker doors, only the cold by-pass air is reversed. The hot gases continue to exit rearwards through the central exhaust as they do in 'forward thrust'.

So, once the blocker doors are fully deployed and RPM increases, hot gases exhaust (forward thrust) increases, TGT increases and reverse thrust from the blocked air increases.

So the only incorrect statement is b).
a), c) and d) are correct statements.

wanabee777 19th November 2015 12:28

Bad question.

It depends on the type of reverser or how you define "blocker doors".

https://en.wikipedia.org/wiki/Thrust_reversal

Gryphon 20th November 2015 17:44

They are looking for the incorrect statement, that's B assuming core air is not reversed.

wanabee777 20th November 2015 18:36


They are looking for the incorrect statement, that's B assuming core air is not reversed.
It's still a poorly phrased question.

D driver 22nd November 2015 03:56

thankyou averyone i see how b is correct.:ok:

No Fly Zone 22nd November 2015 07:52

FE Hoppy+++
 
IMO, several nailed it very well, but FE Hoppy was first and sort of said it best. And please do not be mislead as the question asks for the incorrect response. You're doing just fine!:D


All times are GMT. The time now is 08:09.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.