SU25T: Engine went off during upside down flight

[BlackWidow]

S!

 

As I was flying with shamandgg some formation mission I went from

tight formation to a safe distance formation, made a roll and continued

flying upside down next to him. But after , let's say five seconds, my

engines went off in 200m rad alt. That's fun! Is it because we took four

external fuel tanks with us and therefore the fuel did not flow when I was

upside down???

 

I throttled back to idle, started both engines and everythíng was ok again

but... why did this happen???

 

Christian

[SIX oclock]

you were at 200m with engine off and didn't crashed? Wow! :icon_wink

 

 

How long did it took to regain enough thrust?

[Laivynas]

Avoid negative G`s. ;)

Other way your engine will stop.

(Talking about Su-25/25T)

[BlackWidow]

well, as soon as I realised by looking on my gauges, i would say max 10 seconds... I was flying 600 km/h i think so the turbines had enought spin?? dunno :-).

 

and neg. g... perhaps the plane is not as neutral concerning inputs when flying

upside down. so the aoa is other as when flying normal?

 

Christian

[Gazehound]

You pull negative g's when trying to flying level upside down (plus the -1 from the earth!), you can see this in a fighter better as you can get red vision very quickly.

[britgliderpilot]

Strictly speaking, it's not negative G's that cause the engines to stop - it's just the fact that you're upside down. The Su25T is not designed to cope with inverted flight for long periods of time . . . . .

[169th_Crusty]

Strictly speaking, it's not negative G's that cause the engines to stop - it's just the fact that you're upside down. The Su25T is not designed to cope with inverted flight for long periods of time . . . . .

 

Well, it should be a little more then 5 sec. I would think... 20 or 30 seconds.

Then again, what the heck do I know :)

BTW, early Hornets had about 30 sec. inverted (0 G) before they had to go upright.

[Laivynas]

Strictly speaking, it's not negative G's that cause the engines to stop - it's just the fact that you're upside down. The Su25T is not designed to cope with inverted flight for long periods of time . . . . .

The time of being upside down is determined by a special fuel tank designed for zero or negative G flight and engines` RPM (or fuel flow).