This looks exciting, but let me tell you it’s heart stopping when you’re inside the plane. I did some of those with a Pilatus test pilot many years ago and it was scary. That was before i did my aerobatic rating but still, when such a heavy plane rolls inverted like that … no fun!
Excellent demonstration.
Consider a stick pusher as a stall barrier, it does not prevent a stall, it introduces a barrier to getting there – but a pilot can still get there with effort/super carelessness. More importantly, the stick pusher can fail. The design requirements state that it must not be possible to cause an unrecoverable spin with any use [misuse] of the controls. But this is not one of the design requirements which says that it must be done without unusual pilot skill. Recovering an abused stall might require unusual pilot skill, but it can be done. The pilot might very suddenly achieve unusual skill, if he spins it. So the stick pusher, assuming normal operation, helps the careless pilot not get the plane fully stalled, and in a spin. It was interesting to see the stalls [spins] being done flaps down. Extra points. I usually whip the flaps up when it breaks, as passing through Vfe is likely in a spin recovery.
I’ve never flown a PC-12, but during my spin testing of a modified Caravan, the recovery was as required – it did, but it was exciting! Similar to what you see with the PC-12, the Caravan would easily roll upside down. Bear in mind that the design requirement states “normal use of the controls” during entry and recovery – nothing prohibits the use of ailerons. The Caravan Flight Manual does say that using ailerons during recovery might prolong the recovery, simply because the up going aileron also operates a spoiler.
The recovery at forward C of G consistently resulted in a rate of descent momentarily exceeding 9000 FPM, accelerating to Vne, and 2.8G to prevent exceeding Vne. But perfectly repeatable. Aft C of G spins were very different.
Forward C of G spin video:
“It was interesting to see the stalls [spins] being done flaps down. Extra points. I usually whip the flaps up when it breaks, "
Exactly my reaction to the video. Also g-limits are low flaps-down in the typical piston singles I fly. Does the PC-12 have high g-load limits flaps down?
The certification requirement for G with flaps is usually +2/0, but remember this is part of certification flight testing so normal POH limits are not necessarily applied. I would expect the calculated safe limits to be on the test card for the serial.
