Hi all,
a short while ago I had a discussion about a similar subject with a "Safety Counselor".
The subject was "Downwind take off - loss of engine"
a) I do not generally promote downwind take offs.
b) In this case though it is (in my opinion...) preferable to a take-off into the general wind direction.
The hangar to take off from is at the up-wind end of the runway. Directly after the runway there is a village/town.
Downwind is all open fields, mostly level.
Downwind take off can be done over a blacktop runway or a hard grass area beside the runway.
So far I was always able to creep slightly into the wind (quartering tailwind),
obtain recommended climbout speed (60-65 IAS) before leaving the boundaries of the airport. In case of an engine failure, my selection would be in this case to run it on straight ahead (AS350B3, other aircraft may be less forgiving when putting them down at 30-40 kts....).
c) It was suggested and asked, why I would not hover downwind and then take off into the wind.
To hover downwind in the usual conditions, seems (to me...) no less dangerous than "let the bird run". Especially if it behaves well - no overly itchy tail, good power, good acceleration....
Further, even if I hover all the way to end of the runway (keep in mind downwind...) I still would have to do at least a 120 degree turn (quartering tailwind again) to avoid going over the town at less than 500 ft, although this would be at an altitude of around 500 ft.
Never the less, an engine failure at 500 ft at 70 kts IAS and I still have to go downwind before I can turn into the wind again, is not my choice if can avoid it!
The town is arranged in such a manner, that even from a 1000 ft it would be hard to find a place to go if an auto should become necessary.....
Back to the downwind hover: Obviously it would be a rather high torque, low speed situation. If a power failure occurs in this situation I would not consider it any less challenging than a run-on at 30-40 kts Groundspeed.
I had a sudden engine stoppage in a R-22 in a hover (my fault/stupidity) and was not prepared for the violent fast turn to the left!! It is quite a difference from practising a soft (or even snappy) engine failure in a hover (you are prepared for it and counting on it!), to the real thing. This "occurance" happened into the wind. Don't want to know what it looks like downwind!
My preference would be with the downwind run-on in my specific case.
d) Again! I do not promote downwind autos as a general maneuver!
Off course one has to take into account all factors in a specific case:
1 - Straight downwind versus slightly quartering downwind
2 - Engine power available for take-off (useless when the engine is gone, but struggling to stay in the air while trying to run for take-off is not good enough...)
3 - Aircraft - familiarity, tendency to run well on the ground, roll-over tendency, weight/power
4 - Terrain in case of emergency
5 - Above all, pilot proficieny
In this specific case I prefer the down wind take-off, because:
1 - Enough Power to get going fast
2 - Aircraft is very well behaved on the ground (running on situation)
3 - Aircraft has a very strong landing gear
4 - Complete avoidance of over flight of the town
5 - Fraction of time spent in adverse (tailwind) situation versus prolonged downwind hover (see my rational about hover power failures above)
6 - Terrain favorable for run-on landing
My personal choice in this specific case is to limit the exposed time as much as possible.
Of course before going towards "advanced maneuvers", one has to analyze the specific situation and if possible, practice simulated situations with a proficient instructor.
Remember, there is no old heroes!
If you are "working" with your helicopter, a lot of times you would have no choice but downwind (or any wind), because it is the only option.
No matter what, keep flying the aircraft until everything has stopped moving.
If the engine fails you really just care to be able to walk away, no matter if the airframe ever flies again - if it does, it is a bonus...
Back to lurking!
Fire away!
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