Originally Posted by
blagger
Genghis - A turnback (in the RAF anyway) is a manoeuvre to return to the airfield because the landing area options ahead are unsuitable. It is not soley focussed on a downwind landing on the runway. The airfield is a known environment, flat, with limited obstacles etc.. where you have better options for a forced landing than the terrain ahead. The subsequent landing could be anywhere on the airfield, it may be downwind on the runway but that would depend on a host of factors on the day. Most of the real SEP turnbacks I have known have resulted in a landing on the grass outside of the runway surface.
I take your point, but a couple of quick calcs:
Typical light aeroplane, best glide 70 kn, so we fly the turnback at 75, using 45 degrees of bank, you get a 300 metre turn diameter.
Vigilant 60 knots, 30 degrees of bank, you get a 340 metre turn diameter.
Higher performance - try a Piper Arrow: 79kn best glide, so 84 turnback speed, 45 degrees of bank, gives 380m turn diameter.
To some extent, most aeroplanes at most airfields you are going have to turn beyond 180 degrees and then correct roughly back onto the runway heading. Apart from a big military airfields, most times and places, 300 metres likely to be well outside the airside perimeter.
So, I think that a 270 degree total heading change is realistic. This is what Rogers used in his paper.
My increasingly distant recollection of Bulldog, Tucano and Hawk practices is that turnbacks were always trained back onto the runway also.
G