Bidule 55 - Newbie tower

[dr.tom]

Hello,
here's my Bidule (didn't find 55's topic here)

MVVS 58cc engine biela 22'' 3 blade and Falcon 24'' props









already did the main landing gear mod,
but the rest of it seems ok.

do you have some tips for towing (many I see online are for foamies both towing and glider plane)
glider seems to overtake me in turning point (like slingshot)

My maiden tow was 5 meter glider around 33 pounds, adrenaline rush for both of pilots

https://youtu.be/PV04lId2nlc

https://www.youtube.com/watch?v=t4mwoDTEkuM

[Stew2]

I was taught that towing is all about the rudder and big gentle turns. It seems like you have plenty of power for the size and weight of glider you are towing, so more climb in the turns should help also. The glider pilot should just work to keep the wings level. This is often done with aileron opposite to the direction of turn. Especially if the turn is tight. Let the tow plane haul the glider around the turn, the opposite aileron is needed because of the roll that will be generated by the yawing of the glider as it is pulled through the turn. Big, low bank angle turns by the tow plane can only be accomplished by using rudder. There is not a lot of aileron input when towing. The last thing you will do with a tow pane while the glider is on tow will be to bank with aileron and pull it around the corner with elevator. The tow plane is almost just a 3 channel aircraft of rudder, elevator and throttle when a glider is on tow. The tow plane will never outrun the glider in a diving tow, if the glider is catching up, the only way to slow the glider down is to initiate a climb, the glider will only accelerate in a dive, it will slow in a climb. Keep trying, and have fun!! It is a blast for both pilots!

[lenb]

Hey Doc.

Nice looking 55 there...
Congrats on the new towplane and welcome aboard

[Mosquito]

Nice job on the video. Like to hear gentle music in the background that doesn't overwhelm the viewer. Looks like you nailed the tow on the 3rd video. Nicely done.

[JimD]

First, congratulations on the new plane and the success with aerotowing so far!

After watching your video several times, here are a few thoughts and observations.

Typically, the sailplane needs to be higher than the tow plane (relative to the flight path). I noticed that the tow line was almost straight back much of the time. The tow line should be angle upward from the tow hook. Enough that the tow line would clear the top of the fins with any side to side movement of the sailplane. BUT, not too high...you will find that there is a sweet spot whete both sailplane and tow plane are happy. Sailplane pilot usually needs to keep just slight finger pressure on up elevator to stay in the correct high tow position.

What you absolutely don't want is the tow line pulling down over the stab and putting pressure on the tow planes elevator...watch your video, this happened briefly at one point of a tow.

Next, the tow plane needs to maintain a climbing atitude. The sailplane can quickly pick up speed and over fly the tow line in level or slightly downward flight on the part of the tow plane. It seemed that your tow plane started a slightly downward flight path in your turns. As Scot mentioned, you really want to avoid banking (especially steeply banking) turns. When the tow plane banks, the wings produce less lift and you can quickly find yourself in a diving turn. At this point, the sailplane will over fly the tow line and it will go slack. When the tow plane levels out and begins to climb again, the tow line will quickly tighten up and then you get the slingshot effect and send the sailplane rocketing past the tow plane!

What you want are large flat turns with the sailplane keeping its wings level and sliding around the turn like a water skier behind a tow boat.

Aerotowing is like ballroom dancing, the partners need to flow along coordinating their movements one with the other. Pilots need to talk to each other. As a tow pilot, you will find that each sailplane pilot has their own style and way of moving...so each tow session is like dancing with a collection of partners.

The advice I would add to what Scott said is plan your turns ahead. Large flat turns don't happen in an instant. Initiate the turn with rudder and use the ailerons as needed to keep your banking shallow. This will sometimes result in adding aileron opposite to the direction of the turn. Figure that your tow plane will not start to turn immediately, think...start turn...count 1, 2, 3...and then turn will begin.

A final thing, with the drag of the sailplane on tow, the torque of your engine will be exaggerated and the nose of your tow pane will want to yaw to the left...so holding finger pressure right rudder throughout the climb will be very helpful to counter this. Because of this torque effect, you will notice a difference in your control inputs between turning right vs left.

Enjoy...aerotowing is a beautiful thing.

[Steve P]

Great input from one of the best tow pilots out there!!

I have to respectfully disagree with the comment about the sailplane pilot needing to apply up elevator inputs on tow. Sailplanes should be trimmed in launch setting to tow slightly high on the tow plane without constant elevator inputs or maintaining stick pressure for up elevator. This launch setting will obviously take several tows to refine and is different for each sailplane, but is the goal to have a sailplane that consistently tows in a predictable manner. Managing sailplane pitch changes relative to the tow plane, at various viewing angles, under tow speeds and at increasing altitude is challenging at best.

[JimD]

The takeoff...

As the tow plane accelerates, let the sailplane break ground first and establish the high tow position...then tap up, break ground, and establish and angle of climb that keeps the tow line tight and both planes at a comfortable airspeed.

okay...my $0.02 plus a penny!

[dr.tom]

A big thanks to all of you for such quick and detailed replyes.
I will try to implement your suggestions nex time we do aerotow. Hope soon.
Bidule is great, I was scared if I can pull it at all since the glider is twice heavier than tow plane, but it seems like power is ok, more could not hurt definitely, but enough for the job, and for perfecting the technique

thanks,
will post some more when I film it.

[dr.tom]

quick question,
what about Gyro that can level plane by itself

https://www.motionrc.com/products/eagle-a3-pro-6-axis-airplane-gyro-w-one-click-auto-recovery-system

I intentionally set it with some % of climb, further setting in flight with slider/pot.
then once in air I just apply rudder for turn and glider has steady, stable, predictable tow pattern.

does anyone here use gyro on tow plane?

I just can't wait to test it with glider attacher

https://www.youtube.com/watch?v=Mu2kq-k7NjY

[lenb]

We started using a gyro this past season in the Cmelak, ( Aka Smelly yak ). The primary use for this tug is just reducing work load in very windy conditions on the mountain as well as just plane ol' fun.
I have to say its worth doing. The tug flies very well and slow speed is extremely comfortable.
I use a powerbox I-GYRO

[dr.tom]

Thnx,
today we hit 1800 feet (550m) above takeoff point
and glider released because it was programmed for GPS triangle contest at that height, next time we will try even higher just for fun

it was a blast

https://youtu.be/AUR76g-ERdc

[Stew2]

Sure sounds like you are getting the hang of it!! It is a ton of fun! Enjoy and have a great new year towing.