Originally Posted by
Reely340
Firstly I'm merely a recreational S300C Pilot, who only once could experience a Cat-A takeoff demonstration during someone's EC135 rating renewal. (of course during daylight, at an airfiled)
I can't help but challenge the departure. I would have recommended/conducted
a) a vertical towering take off at the farthest possible place of the stadium so that the "Cat-A emergency path in front of me" would be as long as possible,
b) and of course from a position where the vertical takeoff would render the AC in headwind, once above stadium height..
Reasons:
Climbing vertically, the necessary amount of attitude change to "emergency nose down" is less than when being in the nose up "climb backwards portion" of a CAT-A dep.
A towering take-off is not a CAT A profile. You wouldn’t normally do one in a ME helicopter unless there was an issue with power available, in which case, you might be asking what went wrong at the planning stage. If you were power limited and used a towering take-off, you would clearly run out of acceleration from ground effect before being able to safely gain forward airspeed in that environment. If you had the power to climb out, there is no advantage of that profile over a steady vertical climb at a weight and power setting allowing you to climb OGE.
The biggest risk of choosing a far end departure would be of losing situational awareness and hitting the roof of the stadium with a part of the aircraft you cannot see. The lateral and vertical references are not close in so there is a considerable risk of drift. The pilot of the incident aircraft had the pitch markings for lateral reference (and probably cockpit indication of drift too). He would also have been able to control the angle of his departure from these reference on the ground. If you are already well back and drift backwards unwittingly during the take-off, the distance to the obstacles behind and above would be further reduced increasing the obstacle collision risk. Objectively, this is probably the biggest risk during such a departure. One other consideration is that the AW169 would have been able to conduct a controlled rejected take-off in the event of power loss and do this with less distance required than an S300.