poor lateral control on a slow tow?

On Wed, 05 Jan 2011 09:04:12 +0000, Doug Greenwell wrote:

At 02:48 05 January 2011, bildan wrote:
On Jan 4, 7:13=A0pm, AGL wrote:

Has anyone tried some flaps in an integrated flap machine (which
reduces stall speed) to see if the wallowing goes away?

With every flapped glider I've flown, negative flap improves aileron
response fairly dramatically. Positive flap does lower the stall speed
a little.

I've flown a 20 meter Nimbus 2C ballasted to 11 lbs/sq ft wing loading
behind a tug pilot accustomed to towing 2-33's. The speed was low
enough to need +1 flap but it didn't wallow. The tug pilot turned off
his radio when he got tired of me yelling for more speed than what he
"knew" was right.



Sorry if this is an obvious question (never flown a flapped glider), but
with an integrated flap system what is the relative movement of the
ailerons and flaps? Presumably the ailerons don't move at all for
negative settings?

On an ASW-20 flaps and ailerons move together so the trailing edge
remains straight with the stick central in the flying flap settings: +8
(thermal) through -9 (max negative flap). When stick is moved laterally
the flap deflects half as far as the aileron. In landing flap settings
the ailerons mover to -8 degrees - what the RC glider guys call 'crow
mode'. This reduces tip stalling tendencies and the handbook says this
also increases drag.


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

At 13:09 05 January 2011, Martin Gregorie wrote:
On Wed, 05 Jan 2011 09:04:12 +0000, Doug Greenwell wrote:

At 02:48 05 January 2011, bildan wrote:
On Jan 4, 7:13=A0pm, AGL wrote:

Has anyone tried some flaps in an integrated flap machine (which
reduces stall speed) to see if the wallowing goes away?

With every flapped glider I've flown, negative flap improves aileron
response fairly dramatically. Positive flap does lower the stall
speed
a little.

I've flown a 20 meter Nimbus 2C ballasted to 11 lbs/sq ft wing
loading
behind a tug pilot accustomed to towing 2-33's. The speed was low
enough to need +1 flap but it didn't wallow. The tug pilot turned
off
his radio when he got tired of me yelling for more speed than what he
"knew" was right.



Sorry if this is an obvious question (never flown a flapped glider),
but
with an integrated flap system what is the relative movement of the
ailerons and flaps? Presumably the ailerons don't move at all for
negative settings?

On an ASW-20 flaps and ailerons move together so the trailing edge
remains straight with the stick central in the flying flap settings: +8
(thermal) through -9 (max negative flap). When stick is moved laterally

the flap deflects half as far as the aileron. In landing flap settings
the ailerons mover to -8 degrees - what the RC glider guys call 'crow
mode'. This reduces tip stalling tendencies and the handbook says this
also increases drag.


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


Ok - so that would help in reducing stall speed slightly, but would not
help with the spanwise lift distribution.

Is the aileron/flap interconnect a standard arrangement, or are there
flapped gliders without it?

On 1/5/2011 7:11 AM, Doug Greenwell wrote:

Is the aileron/flap interconnect a standard arrangement...

Kinda-sorta, "Yes, but..."


or are there
flapped gliders without it?


....because the answer to this question is also (if unequivocally so), "Yes."
(I've owned 3.)

Regards,
Bob W.

P.S. Very e-e-enteresting discussion with (apparently ) real potential to
clarify some folks' understanding of things. I remain in the F = Ma camp!

At 17:59 05 January 2011, Bob Whelan wrote:
On 1/5/2011 7:11 AM, Doug Greenwell wrote:

Is the aileron/flap interconnect a standard arrangement...

Kinda-sorta, "Yes, but..."


or are there
flapped gliders without it?


....because the answer to this question is also (if unequivocally so),
"Yes."
(I've owned 3.)

Regards,
Bob W.

P.S. Very e-e-enteresting discussion with (apparently ) real potential
to
clarify some folks' understanding of things. I remain in the F = Ma
camp!


Thanks - so the question of whether flaps make things better or worse on
tow is also going to be 'it depends' ... :-)

It's certainly been unexpectedly interesting - having only recently
returned to gliding I'm having a load of fun improving my flying, but
also a load of fun trying to understand what is happening from an
academic/technical point of view. You can't argue with F=ma ... but
which 'F' and which 'a' and what direction they are in is another
matter!

Ok - so that would help in reducing stall speed slightly, but would not
help with the spanwise lift distribution.

Is the aileron/flap interconnect a standard arrangement, or are there
flapped gliders without it?

It's optional on a 1-35. (some have it, some don't) but I'm not sure
about the others. Those who have flown both don't report much
difference.