Originally Posted by
jessie13
Having seen a few crashes over the year (Sea King, Black Hawk, Scout, Wessex, UH-1H), There are as many ways to shut a helicopter down as there are types. Some need DC power, some AC, some need to shut a HP cock or wind down a throttle or retard a PCL. Jo Public is not going to know or even try. If the crew are that incapacitated, its very likely that (A) the cockpit is inaccessable (B) the engines have fodded and have shut down anyway or (C) there is no-one alive to rescue. I've been trained in the Fire Fighting side of helicopter crashes and we dont attempt a rescue until the fire is out or engines off. It would be a very daunting task to attempt to shut an aircraft down with no knowledge, a possible fire hazard and an engine whining near by. In regards to fires, none of these aircraft I saw caught fire but fuel was prevelant at all except the Black Hawk crashes. The Black Hawks crash worthiness really comes into play because the fuel tanks were still pressurised!
Actually the Blackhawk fuel system was designed to be very crashworthy. The fuel cells are not pressurized during operation but instead the engines utilize a negative pressure to draw the fuel from the tanks into the engine. When the engine is no longer running the fuel hopefully remains in the fuel cell
and the negative pressure in the system returns to ambient.