Michael wrote:

Robert Ehrlich wrote
This will work on approach, when you have the nose down attitude
corresponding to the flaps setting but not in the situation of my
initial question, i.e. just after a botched flare, a few feet above
the runnway and no nose down attitude. In this case retracting the
flaps will cause a loss of drag, but no so huge, i.e. the drag will
much more than in zero flaps or zero spoilers configuration

I do not concur. Imagine, for example, a similar situation involving
a glider with approach flaps and spoilers, such as the Blanik L-13.
It is normally landed with full flaps, and spoilers are used for
glideslope control. It is also a common primary trainer, so the
situation you cite comes up with some regularity. The solution is to
retract the spoilers - but you still have flaps hanging out. How is
this any different from retracting Schreder-type flaps to 30 degrees?

and there
is no gain in lift and no change in the stall speed, you don't have
the altitude that you can convert into speed, so I think that you are
going to fall on the ground, with a slighly increased delay compared
to what would happen if you didn't retract some flaps.

Actually, you will fly onto the ground, and if you're not careful you
will float. With the flaps retracted to 30 degrees, the HP-11
certainly had a tendency to float even when brought in at very low
airspeed. In fact, after some experimentation I came to the
conclusion that if my flap mechanicsm were to ever fail with the flaps
at less than 30 degrees, I would need about 2 miles of runway to stop.


OK, I have no experience on this kind of ship, I was just trying to
figure how to handle this situation. What you are saying is that
in the range 30-90 degrees on this ship, flaps work like spoilers
on usual (from my point of view) gliders, i.e. retracting them to
30 degrees brings the drag at a level similar to that of a non-flapped
ship with spoilers closed, without change in lift. So the important
thing in order to be able to recover from the 3 most common mistakes
is to have the flaps at more than 30 degrees when you begin the flare.