Originally Posted by
Torquetalk
A towering take-off is a SE 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.
Onyl partly understood. In both towering and Cat-A, you are at nil or negative horizontal speed and need to pick up forward speed to try and flare.
I merely suggested the towering (vertical) takeoff to reduce risk of drift at night, (which definitely is an issue with Cat-A backwards climb).
I must admit I don't know the crosssection of such a stadium:
when the inner roof tips are arched far inwards then climbing in any other location than smack dab in the middle of the stadium would be asking for building contact, I can see that.
Originally Posted by
Torquetalk
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.
My take is that climbing vertically or Cat-A style for whatever reason into a tailwind location nils TR failue recovery.
With the TR "gone", MR torque and tailwind will do to the airframe whatever they see fit, nullifying any Cat-A dep. "recovery options".
That is if there are any "recovery" options at all for "serious TR loss at the end of a Cat-A climb in confined locations", I doubt that, any takers?
So taking one step back, I'd say this accident is a case of "vanity killed the cat", considering that right outside his stadium there are plenty of better, not confined takeoff spots.
Given that fact that even the PPRuNe pros here have confirmed that in this kind of scenario a serious TR failure is next to impolssible to recover, and comparing alternatives right outside the stadium one can't help but wonder why this kind of showing-off departure got green lighted in the first place.