Flaps/No flaps...practical difference??

JS has a point about towing without flaps. The common call is to tell the tow pilot you are full of water. If you are the only standard glider on the field and the tow pilot has a flapped ship, you find yourself mushing off the runway. Give a speed for the tow pilot. (still picking crap out of my shorts.)

If cross country flight is a part of your plans I don't understand why landing off field would not be a large part of the flaps/no flaps decision?

Using flaps can get you into a field safely vs overshooting. I can touchdown and stop without brakes on a grass strip (tail skid ) in 450' with an ASW 20a max positive flap setting . The stall speed is down to 36kts so even if I hit something it will be a considerably slower speed .

Dry the stall speeds are the same, Discus 36kts, so I don't really understand what the extra workload buys you here.

I was talking about stall speed wet.

On Thursday, August 15, 2019 at 5:43:09 PM UTC-7, Delta8 wrote:
The stall speed is down to 36kts so even if I hit something it will be a considerably slower speed

On Thursday, August 15, 2019 at 5:43:09 PM UTC-7, Delta8 wrote:
If cross country flight is a part of your plans I don't understand why
landing off field would not be a large part of the flaps/no flaps
decision?

Using flaps can get you into a field safely vs overshooting. I can
touchdown and stop without brakes on a grass strip (tail skid ) in 450'
with an ASW 20a max positive flap setting . The stall speed is down to
36kts so even if I hit something it will be a considerably slower speed


Many Moons ago flying in a contest out of Fairfield, PA, flying an ASW20a- My only option at the time was a college soccer field. I flew one 360 to scope it out. With full flaps and judicial use of dive breaks the 20 comes down like a helicopter. I chose the diagonal and was stopped with room to spare.


--
Delta8

Having flown a lot both ASW20 and D2, I would not try to land one glider in a place I would not land the other as well.

On Friday, August 16, 2019 at 9:24:25 AM UTC-7, krasw wrote:
Having flown a lot both ASW20 and D2, I would not try to land one glider in a place I would not land the other as well.

Ditto - ASW20, Discus 2 and Ventus 2bx experience under my belt. I have never felt there was a place I could land one of the flapped ships and not the D2.

(although the "Jesus" flap setting of the earlier ASW 20s was interesting!)

Mike

Originally Posted by Mike the Strike

(although the "Jesus" flap setting of the earlier ASW 20s was interesting!)

Mike

I used them every flight . My trailer is halfway down a 2000' strip and not wanting use a tow vehicle more than necessary . Spoilers in at 40' and flare at 20' seems to work well. The angle of descent is 4 to 1 .
I see why they did away with that position in later models , if you decide to move up a setting below 200' between any wind gradient and higher stall speed you're in trouble .

Having flown a lot both ASW20 and D2, I would not try to land one glider
in a place I would not land the other as well.

Ditto - ASW20, Discus 2 and Ventus 2bx experience under my belt. I have
never felt there was a place I could land one of the flapped ships and not
the D2.

(although the "Jesus" flap setting of the earlier ASW 20s was
interesting!)

Captain Obvious here (maybe)...

There's a world of difference between 'mere' camber-changing flaps (with or
without a 'landing' position) and large-deflection landing-flaps in terms of
steepest-glide-angle at approach-speed, and reduced (compared to unflapped
ships of equal span) stall speed, everything else being equal (which of course
it ain't). The devil's in the details.

Yeah, likely the main benefit of stalling-speed-reduction occurs somewhere
around (say) 30-ish degrees of flap deflection, beyond which the remaining
aerodynamic effect is pretty much additional drag, and yeah, manufacturers of
'flapped ships (w/o large deflection capability)' almost certainly optimize
such designs (and their landing spoilers) so that the *primary* purpose of the
flaps is to maximize soaring-performance-range for some design-targeted span
(and not maximize short-field capability), and hence == when considering
*these* sorts of flapped designs == there's arguably little
landing-capability difference between flapped and unflapped ships.

But to suppose that's true for *all* flapped designs (i.e. those w.
large-deflection landing flaps, e.g. some early versions of ASW 20s, pre-D
versions of PIK-20s, and a few, semi-rare (even in the U.S.; likely even more
rare in EASA-land) U.S. designs (Nugget, SGS 1-35, Zuni, many older HPs,
etc.)), is incorrect. Depending on the ship, *seriously* incorrect.

Most U.S. pilots w. 1-26 experience would likely agree no other glider would
be their first choice for landing in a small/approach-obstructed field. I
would, too, but for the HP-14 I flew for several hundred hours, more or less
immediately after my 1-26 time. The Zuni in which I have most of my
flapped-ship time, not so much, though its actual touchdown speed is (thanks
to its flaps) lower than all other 15-meter span glass ships with which I have
observational experience since ~1980.

Reiterating...the devil is in the details in the case of 'flaps.' All flaps
aren't the same - not by a long stretch. I chose large-deflection
landing-flapped ships for all my single-seaters, post-1-26, exactly for this
reason...and continue to believe they're something of a 'lost religious war'
in soaring-land.

Point being, anyone seriously claiming 'there's no practical difference in
landing capability' between flapped and unflapped gliders is either genuinely
ignorant, or 'discussionally choosing' to ignore the very real additional
landing-capabilities associated with large-deflection landing-flaps.

YMMV,
Bob - Cap't. Obvious - W.

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On Friday, August 16, 2019 at 6:07:44 PM UTC-4, BobW wrote:
Captain Obvious here (maybe)...

There's a world of difference between 'mere' camber-changing flaps (with or
without a 'landing' position) and large-deflection landing-flaps in terms of
steepest-glide-angle at approach-speed, and reduced (compared to unflapped
ships of equal span) stall speed, everything else being equal (which of course
it ain't). The devil's in the details.

Yeah, likely the main benefit of stalling-speed-reduction occurs somewhere
around (say) 30-ish degrees of flap deflection, beyond which the remaining
aerodynamic effect is pretty much additional drag, and yeah, manufacturers of
'flapped ships (w/o large deflection capability)' almost certainly optimize
such designs (and their landing spoilers) so that the *primary* purpose of the
flaps is to maximize soaring-performance-range for some design-targeted span
(and not maximize short-field capability), and hence == when considering
*these* sorts of flapped designs == there's arguably little
landing-capability difference between flapped and unflapped ships.

But to suppose that's true for *all* flapped designs (i.e. those w.
large-deflection landing flaps, e.g. some early versions of ASW 20s, pre-D
versions of PIK-20s, and a few, semi-rare (even in the U.S.; likely even more
rare in EASA-land) U.S. designs (Nugget, SGS 1-35, Zuni, many older HPs,
etc.)), is incorrect. Depending on the ship, *seriously* incorrect.

Most U.S. pilots w. 1-26 experience would likely agree no other glider would
be their first choice for landing in a small/approach-obstructed field. I
would, too, but for the HP-14 I flew for several hundred hours, more or less
immediately after my 1-26 time. The Zuni in which I have most of my
flapped-ship time, not so much, though its actual touchdown speed is (thanks
to its flaps) lower than all other 15-meter span glass ships with which I have
observational experience since ~1980.

Reiterating...the devil is in the details in the case of 'flaps.' All flaps
aren't the same - not by a long stretch. I chose large-deflection
landing-flapped ships for all my single-seaters, post-1-26, exactly for this
reason...and continue to believe they're something of a 'lost religious war'
in soaring-land.

I've got an RHJ-8 looking for a home, flaps not quite as effective as HP-14
but quite frightening to passengers unused to such a treat of a landing...

On Saturday, 17 August 2019 01:07:44 UTC+3, BobW wrote:

Point being, anyone seriously claiming 'there's no practical difference in
landing capability' between flapped and unflapped gliders is either genuinely
ignorant, or 'discussionally choosing' to ignore the very real additional
landing-capabilities associated with large-deflection landing-flaps.

YMMV,
Bob - Cap't. Obvious - W.


Sure, if you totally botch landing circuit and approach way too high and fast, '20 flaps will get you down sooner than D2 airbrakes. But if you get into this situation, glider you need is ASK21 with flight instructor.