Roll law and stick forces
Salute!
I believe the stick inputs being awry due to spring failure or degradation is a red herring. The pilot commanded and the system responded best it could with screwed up speed and disregard for AoA limits.
The chart of the breakout forces was a surprise to me and I had missed that if posted before. The breakout force is lots lower than the Viper. Ours was 1 lb for roll and 1.75 for pitch. Secondly, the gradient for max command is lots steeper. For example, ours was about 7 pounds to command 2 gees. Then the curve got steep and a 9 gee command was about 31 or 32 pounds.
Secondly, my understanding from looking at the roll laws is the roll command works the same in "alternate" as in "normal". The only difference I see is the max roll angle allowed in "normal", not the command, but actual body-referenced roll angle. So what I see is what I was used to - let go of the stick and the roll command is zero deg/sec. Am I missing something?
As the Bus drivers are now finding out, there are "hidden" aspects of the control laws. Same as we had in the Viper. For example, no stick pressure in roll and zero roll rate command. Not so fast! Turns out that there are flight dynamics which are not completely corrected for. Look at the pic on my profile bio. With that LEF up I had to apply almost full left stick to stay wings level ( it was a control surface limit, and the engineers told me that I only had about a pound or two of authority or would have had to bail). The zero roll rate "law" didn't work. We also saw this when dropping a heavy store from one wing. We had to apply aileron pressure to stay wings level on the pullout and we had thot the jet would maintain zero roll rate. Same deal with allowable control surface deflection.
Only thing that puzzles me is the pilot having to apply roll in the first place. Could be a spoiler or aileron wasn't moving correctly, and a determined manual input was required to override the deflection limits. Same as I had to do with the LEF failure. And remember, control surface movement rates and such use dynamic pressure for "gains". What does the system do when dynamic pressure is deemed unreliable by the system?
later,