Stall spin during aero tow? Std cirrus

At 18:35 23 August 2018, wrote:
I fly unflapped standard ships.
I used to fly a DG300 mainly dry. Tow in 110km/h range is not a
problem.
This year I switch to a Discus 2. It has a big AoA also when on the
ground
=
and
it need about 130km/h dry to have and more speed when it is wet.

Both ship dry has the same weight and the almost the same
surface. I think
=
the main factor is the AoA. The differences are in the AoA and also
in the
=
tow hook position (baricentral for DG300 and on the nose for
Discus 2) who
=
main influence the stability on tow. When on tow we fly at relative
low
spe=
ed at high AoA fly in an uncommon attitude for the glider.

I always say my load and the desired speed at tow pilot befor take
off.
ciao,
giovanni



The D-2 has an Angle Of Incidence (AOI) that corresponds to that of
flapped wing gliders. It came from 15m owners wanting to fly STD
Class competitions, and being allowed to do so with their flaps
locked at the zero setting. It was assumed that these 15 m birds
would be at a disadvantage in the climb because their airfoils were
not optimized to always be at the zero flap setting. It turned out
that the 15 m gliders did quite well in the STD Class, and were
noticeably better in the higher speed regimes due to their lower AOI
causing less (fuselage) drag. Centrair was the first to exploit this
with their Pegase, which is basically a "no flap" ASW-20. Anyway,
the D-2 has this lower AOI, so the visual sight picture from the
cockpit is somewhat more "nose high" at slower speeds than on
previous generation STD Class birds. It will fly just fine down into
the high 30 Kt range, but if you are on tow, the nose is so high by
then that you will have trouble seeing the tow plane. Take it from a
19 year D-2 owner. If the tow gets a little slow for your comfort,
just offset your tow position to the left side a bit. Then you will be
able to see the tow plane in the front right side of the canopy, AND
the tow pilot will thank you for doing it so that he/she doesn't have
to stand on the right rudder pedal so much...

RO

On Sunday, August 5, 2018 at 7:49:48 PM UTC-7, wrote:
Have there been stall spins during an aero tow?

Today, I had a very scary aero retrieve. From being towed to fast to-to slow. Anyways the scaries part was when, the tow plane started to climb and to slow. The indicated speed on the glider was 50 knots and decreasing. The glider kept slowing down and sinking under the tow plane into the wake. By this time the glider felt extremely sloopy and it felt like it was ready to drop into stall. Fortunately as I felt the wing wanting to drop, the tug leveld some and got back to a decent speed.

Yes I did radio the pilot askig for 20 indicated more. And I was attempting to release when I hit the wake, but the release on the standard cirrus is far, and my extention had moved from my legs.


Slight topic creep: As a tow-pilot I always give more speed on tow when requested, but I've also had a complaint later that the climb-rate was very slow. My impression is that Pawnees are very draggy and rate of climb suffers noticeably with extra speed. I've only towed in turbulent air, so can't give any measurements.

To me, this is a "formation flight". If both are "sorta middle of the road", normal may be fine.
Something different (time of glider pilot, turbulence, heavy weight), thou shalt communicate what you want and/or can do!
It behooves BOTH pilots!

Loading a glider to 10-11lbs when the site is used to 6lbs, something needs to change!

Just my take.

I fly rather light wing loading gliders (1-26 SN 002, I weigh about 150lbs) to wet 15M glass full of water (9+lbs) and communicate to the towpilot.
You're BOTH PIC in your craft!
You do right by you!

Say, high altitude density for the tug and a heavy glider.
Glider pilot wants "X" but tug pilot states "no way", wait for another tug, or drop weight.
Don't assume!

We have enough statistics, no need for more, especially if they are avoidable.

On Monday, August 27, 2018 at 6:35:25 AM UTC-7, Charlie M. (UH & 002 owner/pilot) wrote:
To me, this is a "formation flight". If both are "sorta middle of the road", normal may be fine.
Something different (time of glider pilot, turbulence, heavy weight), thou shalt communicate what you want and/or can do!
It behooves BOTH pilots!

Loading a glider to 10-11lbs when the site is used to 6lbs, something needs to change!

Just my take.

I fly rather light wing loading gliders (1-26 SN 002, I weigh about 150lbs) to wet 15M glass full of water (9+lbs) and communicate to the towpilot.
You're BOTH PIC in your craft!
You do right by you!

Say, high altitude density for the tug and a heavy glider.
Glider pilot wants "X" but tug pilot states "no way", wait for another tug, or drop weight.
Don't assume!

We have enough statistics, no need for more, especially if they are avoidable.

Just to point out some places do not have comms between glider and tow. Just signals.

On Monday, August 27, 2018 at 9:03:17 AM UTC-6, Jonathan St. Cloud wrote:

Just to point out some places do not have comms between glider and tow. Just signals.

That's when a face-to-face conversation about what you want/need prior to launch is key.

On Monday, August 27, 2018 at 10:03:17 AM UTC-5, Jonathan St. Cloud wrote:

Just to point out some places do not have comms between glider and tow. Just signals.

Yeah, cuz radios are so, like, expensive and hard to use!

Tow planes without radios (and transponders and soon, ADS-B out) are dangerous, IMO. And there really is NO excuse not to have some kind of radio in every glider.

Our club is getting there, slowly. Unfortunately our most commonly used trainer is a Blanik L-13AC, and our A&Ps can't find a legal way to put a battery in it.

Kirk

On 8/27/2018 9:21 AM, kirk.stant wrote:
...Unfortunately our most commonly used trainer is a Blanik L-13AC,
and our A&Ps can't find a legal way to put a battery in it.
Kirk
I would think a simple fabricated tray with hold down and a mechanic's
logbook entry would be sufficient.
--
Dan, 5J

On Mon, 27 Aug 2018 08:21:14 -0700, kirk.stant wrote:

On Monday, August 27, 2018 at 10:03:17 AM UTC-5, Jonathan St. Cloud
wrote:

Just to point out some places do not have comms between glider and tow.
Just signals.

Yeah, cuz radios are so, like, expensive and hard to use!

Tow planes without radios (and transponders and soon, ADS-B out) are
dangerous, IMO. And there really is NO excuse not to have some kind of
radio in every glider.

Our club is getting there, slowly. Unfortunately our most commonly used
trainer is a Blanik L-13AC, and our A&Ps can't find a legal way to put a
battery in it.

Use a handheld?

Some ICOM models can be fitted with a mic on a coiled lead and can be
Velcro'd to the panel.

When I bought my Libelle (in the UK) it had an ICOM (A3 IIRC) fitted on
the panel without its battery. The radio was mounted on a Velcro disk
stuck to an 80mm blanking plate and powered from the aircraft battery.


--
Martin | martin at
Gregorie | gregorie dot org

At 15:48 27 August 2018, Dan Marotta wrote:


On 8/27/2018 9:21 AM, kirk.stant wrote:
...Unfortunately our most commonly used trainer is a Blanik L-
13AC,
and our A&Ps can't find a legal way to put a battery in it.
Kirk
I would think a simple fabricated tray with hold down and a
mechanic's
logbook entry would be sufficient.
--
Dan, 5J


I asked the tug pilot for 5Kn more last week and he said "At the rev
limit"...Ballasted Ventus behind a Euro fox with fine prop to optimise
towing 2 seaters.I was at 60 Kn so not too marginal.
You cannot beat a pawnee but you can break the bank using them.

On Monday, August 27, 2018 at 8:21:17 AM UTC-7, kirk.stant wrote:
On Monday, August 27, 2018 at 10:03:17 AM UTC-5, Jonathan St. Cloud wrote:

Just to point out some places do not have comms between glider and tow. Just signals.

Yeah, cuz radios are so, like, expensive and hard to use!

Tow planes without radios (and transponders and soon, ADS-B out) are dangerous, IMO. And there really is NO excuse not to have some kind of radio in every glider.

Our club is getting there, slowly. Unfortunately our most commonly used trainer is a Blanik L-13AC, and our A&Ps can't find a legal way to put a battery in it.

Kirk

I know, I have seen radios as low as $250.