cannot reproduce the Viper not able to hold 9.3g while bleeding speed

[DummyCatz]

As mentioned in a previous flight control system mini-update, the Viper was able to hold 9.3g when energy sufficient, but initial tests suggest that max-g limit would be reduced by 0.1-0.3g while bleeding speed, which is usually the case in a BFM situation.

Track is attached.

 

Viper not holding 9.3g while bleeding speed.trk

Edited May 23, 2023 by DummyCatz

[skywalker22]

There is a lot of variables in play here like altitude, air speed, weight and aerodynamics. Check my video from a week ago:

NOTE: at the moment, this is a WIP from ED side, they are studying this "issue".

 

[BIGNEWY]

All seems ok here, please always include your track replay from your test. 

Please check your weight and your altitude for the test.

thanks

[DummyCatz]

Hi, holding 9.3g does not mean holding speed as well. The test is to check the top right portion (max-g line) of the EM diagram, whether the F-16 is able to hold and keep a max g-limit while bleeding speed or increasing speed. As long as the EM diagram of the same test condition shows that the max-g line is there and attainable, it's worth to test.

From an aero and FLCS point of view, the max-g is attainable when:

1. AOA < 15 deg (CAT I) where FLCS starts to decrease g-limit.

2. The horizontal stab doesn't use up all its authority (travel range) in supersonic flight when the aerodynamic center moves backward.

I may need more tests (and yes tracks) to come to a conclusion, but my initial tests do suggest that it's somewhat related to the bleed rate, that if the aircraft bleed its speed during a max-g pull, the attainable max-g would be reduced by 0.1-0.3g. This is pretty common in a BFM situation.

Edited May 23, 2023 by DummyCatz

[DummyCatz]

Track is attached to OP with a condition of DI=0, GW around 26,000 lbs and an altitude just above sea level. Notice the decelerating max-g pull before AOA hitting 15 deg.