David Smith wrote:
I have been watching this thread for several days,
we are not going to get practical AoA displays for
gliders in the near future so how is the best way to
get it right as often as possible?

We have the ASI, Attitude and Feel and I guess that
we all use some combination of all 3 to fly efficiently,
so what is efficient?
Is it Best L/D or Min Sink or in between or in a flapped
glider the same AoA with a different flap setting?

Depends what you're doing.

- min.sink is best for climbing in weak lift, not so important in
strong lift, and terrible if you're trying to cover ground.

- best l/d is really only useful if you're stretching glide in
neutral or very weak conditions. If you're flying between
thermals in conditions when you're using a non-zero MC setting
then best l/d is too slow.

- flaps don't change the min.sink and best L/D speeds. Only
ballast does that. At least, that's true for an ASW-20. You
memorize the recommended speed ranges for different flap
settings and work to those, remembering that the flap
setting also affects Vma and Vne.

For circuit and landing it cannot be Min Sink that
is much too close to stall speed.

Efficiency is unimportant at this stage unless you've screwed up and are
too low. For starters, the wheel should be down and that destroys glide
efficiency. If you can't easily fly a planned circuit from high key and
use half brake for most of finals then you've misread the conditions
and/or forgotten how to plan a circuit. For a normal circuit I'd say not
slower than best glide after high key and not below 50 kts + 1/2 wind
speed on base and finals.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |