Originally Posted by
Noeyedear
Many good points are being made, but I would like to add / highlight the following;
1. The vibration was so severe the FDR & CVR thought there'd been an impact. That's pretty violent.
2. The crew were not trained for this event, nor had it ever been discussed. (This wasn't a simple :engine vibration" event).
3. Bombardier, to my knowledge have no QRH Procedure for Fan Blade Off.
4. By all accounts, these guys were competent and well trained, but perhaps felt they needed to bypass years of training to get the engine shutdown urgently or perhaps risk an airframe failure.
There has been an similar failure in a Gulfstream G650. Similar engines / airframe. The crew managed to contain the situation. Based on the FDR data, the manufacturer was able to come up with a procedure to manage the situation in future. That data has also created a sim profile and I can tell you its extremely violent and disorientating, and I was expecting it.
Rolls Royce are also aware of FBO (Fan Blade Off) events. Draw your own conclusions.
I can understand why the crew felt the need to shut it down pronto. The challenge is to be able to read the engine gauges when the aircraft is shaking so violently and convince yourself the aircraft will hold together while you figure it out.
Before you say something logical like "pull them both back to idle, advance 1 at a time", that apparently doesn't work conclusively. Counter intuitively, what works in the G650, is increasing airspeed to MMO / VMO at idle power and only slowing (without speedbrakes) once you get to 10.000'. Now, try figure that out when you've never seen the failure or trained for it and its happening. In a warzone.
RIP to two guys doing the best they could on a bad day.
In that place, could they even get down to 10,000 feet without hitting something?