A couple of years ago an RAF Puma pilot was on a check ride with instructor.
The instructor pulled both engines to ground idle to simulate double engine failure.
At the pre determined height above the ground, the instructor said "OK thats low enough, climb away".
As the pilot pulled collective it quickly became apparent that both engines were still at idle.
They managed to get a mayday call out just before contacting the ground, it rolled over suffering severe damage but all crew scrambled clear with minor injuries.