Glider Handling on Tow

At my club in the Uk we have a Pawnee and a Supercub for towing.
with 80 mph on the Pawnee the glider behind is gettting 60-65 knots...ok
for K21 's and the like but you get distressed LS8's and asg29 pilots
calling asking for more speed...especially if full of water.! This seems to
be caused by the pitot position with the Pawnee in a unatural climb
psositon with a glider on the back. Take the speed to 90mph and they are
happy as they get 70knots on the back!!
Now to the Super Cub( 180hp) With 60 mph on the dial the glider behind is
getting 60-65 Knots( same as Pawnee at indicated 80mph) Once again this I
believe is due to pitot and unnnatural climb angles. speed up to 65 mph and
the guys on the back are happy getting 65-70 knots
So we have 2 different tugs indicating 20 mph differences to give the same
speed to the glider!!!
If you know this , dont shout at the tug pilot but politely call on radio
for 'a few more knots please'
hope that helps
Regards from the Uk


At 18:44 11 November 2013, Andy Melville wrote:
At 13:14 10 November 2013, Papa3 wrote:
I've towed with my LS8 at many sites in many different conditions behind
ma=
ny different towplanes, and I've never had the problem you describe at
an
I=
AS (on my side) of above 65 kts. If the Pawnees (PGC?) were truly doing
80=
mph (70 kts), I can't imagine how this would be described as a "slo
tow".
=
I've had tows that dropped down into the low 60s or even high 50s
(kts)
w=
here it felt squirrely, but that's a full 10kts slower than what you are
de=
scribing.=20

Just a data point.=20

P3



On Saturday, November 9, 2013 10:40:05 AM UTC-5, John Carlyle wrote:
Thanks again for your thoughts, Steve. Sorry for my delay in
responding.=
=20

All of our slow tow incidents have occurred above 500 feet; none of us
ha=
s ever had a problem near the ground. Our airport elevation is 700 feet
wit=
h unobstructed horizons, and the temperatures on the days of th
incidents
=
were mostly in the 70s. The Pawnee pilots claimed that they had been
mainta=
ining 80 mph during the climb to that point; but when they went to 90
mph
t=
he handling problem for the remainder of the tow was gone.=20
=20