Most gliders can do this and the pilots train to that standard..

Departure problems below 200ft AGL, tow plane power problems.. rope breaks
or tow hook failures.. and the idea is to land straight ahead as quickly as
possible and get stopped.

Above 200ft AGL (which most glider/tow combinations can get to about 3000ft
after start of take off roll), if the rope breaks, tow plane says.. GET
OFF!!.. the glider pilot can pitch down for airspeed and begin a turn back
to the departure runway.. land opposite the direction of take off and have
enough energy to roll back to the starting point.

A nice tow pilot will allow the tow to "Drift down wind the cross wind" on
climb out, so if something does happen the glider can turn into the wind
when returning to the runway.. turning away from the wind can push the
glider to far away (tailwind on base) and make returning to the runway more
difficult.

This maneuver is part of the practical test standards, though most DE's will
wait until 300ft or higher and most CFIGs will review the procedure on BFRs.

Our "Training glider" has a L/d of 23-1. Schweizer 2-33.

BT

"Harold" wrote in message
...
If a small single engine plane can out-climb its engine-out glide ratio
from
take off through the top of climb point, wouldn't it follow that it can
always theoretically make it back to the departure airport in the event of
engine failure ? Assuming straight out departure, no wind, and the
altitude
loss in the 180 turnback is offset by the runway portion you didn't use.
If
my best glide is 85 KTAS and it loses 700 fpm at that speed, shouldn't I
be
guaranteed I can make it back if I climb at 84 KTAS and 701 fpm ?