On Jan 30, 8:35*am, T8 wrote:
On Jan 30, 8:36*am, "

wrote:
The pilot could have also pulled back on the stick, which might have
restored the balance of lift, drag, and weight, and arrested the high
sink rate. *

No way. *He'd have gone in (very) hard on the tail.

It's probably possible to land a 15m glider in negative flap, but
you'd need a final approach speed of *70 kts to do it. *From the
description of this incident, it sounds like the pilot was closer to
50 kts and certainly under 55.

You need to keep in mind that flaps change wing incidence, tail
incidence (relative to wing), and especially max CL. *All at once.
This pilot made two mistakes (flaps not locked, too slow too high -
accident would not have happened if he hadn't had to close the
spoilers!) and a very clutch response that saved his ass.

Uncommanded flap changes in close proximity to the ground or other
aircraft are life threatening. *You need procedures and control locks
that absolutely prevent this.

My $0.02.

-Evan Ludeman (15m guy)

I used to rent a C-150. The flap toggle on that airplane was spring
loaded, and if you were not careful, the switch would flip up and
start retracting the flaps after you selected max flap setting. This
happened to me on a short final sometime ago. I had just selected full
flaps, 40 degrees (I think) and had perfect pitch and power for a
touchdown on the numbers. Suddenly it seemed like I was falling out of
the sky.............so I gave more throttle, pitched down a bit more
and then decided I better do a go around. Imagine my surprise when I
noticed the flaps had already retracted!

Brad