Michael V said:

Spiny Norman said:

This video popped up in my YT feed no doubt because of the recent Learjet crash.
There’s a pretty reasonable chance that they suffered from tail icing and hence loss of control.

YT

FWIW I’d pre-programmed myself if that ever happened to anything I was flying would be to stop trying to fight with the elevator and to use the elevator trim system.

So instead of the relatively small elevator trying to pitch the plane up & own I’d use the entire horizontal stabiliser instead. It’s difficult to get fine & rapid control like that but it’s the only control you’ll have.

…..snip…..

What I don’t understand is why they seemingly kept it at full noise.

I haven’t read that yet. So did they? It seems unlikely. With speed increasing uncontrollably the first thing you do is pull the power back and try to pitch the nose up.
Then like I just wrote, if that doesn’t work you start trimming the nose up.
If that doesn’t work maybe go inverted and maybe try extending the landing gear and maybe the flaps bit by bit.