Glider Tow

kolibri282

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Interesting footage of a glider tow in Sweden. The aircraft seems to be accompanied by a drone, so we have a fairly close look all along the flight path.
Looking forward to the comments of the experts, anything peculiar about the rotor management at the start?
 
Not an expert but done enough on a Bensen without a prerotator to take a stab at commenting on the rotor management at the start, on the 180’s at the ends of the runways, and in general.

Flat calm day, see windsock at 6:10.

Lucky for the pilot. When patting up, face into wind and have the stick forward so rotor disc is flat, if there is any sort of a wind patting up with the disc at the angle of attack that they had is asking for blade sail/flap.

During their turns at the ends of the runway they may have put the stick forward for a bit but then the stick comes back and the disc is at a big angle of attack. At low rotor rpms with any sort of a wind into the disc the rotor will blade sail/flap.

Probably wouldn’t have kept the stick so far back for as much time as they did, had it forward a bit more and would have nursed the rotor rpm’s up a bit more gradually. But then I tend to be cautious.

Some rotors will flap sooner than others, the Dragon Wings especialy. Rotor Hawks were a pretty mild mannered rotor, and others all had slight differing behaviours.

First time I’ve seen that sort of drone footage, it seems an excellent way of recording the run for an instructor student critique after the lesson.

Ideally having the instructor alongside in a chase car in two way radio contact with the student is the way to go for instant advice on what the student is...or is not doing correctly. That way is better for avoiding an accident. Blade sailing can go badly wrong very quickly! In this case probably in the tow truck watching from the back.
 
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That's how I originally learned back in 1988. I drove almost 5 hours each way to get training with Willard Meyer as did many other gyro pilots. We would maybe get a total of 20 minutes of training in a day due to how long it took to get the next person to get in the saddle and take their turn. Finally I went to Farrington's and trained in an Air Command side by side trainer. and soloed in a weekend.

As to the rotor management, that's how it was done. No prerotators back in the day on the towed gliders.
 
It appears that the pilot levels the rotor disk upon landing after the first run -- which is prudent. After later runs, he doesn't. With no prerotator, you're always clinging to as much RRPM as you can, while trying not to tip over as you turn around at the end. Resasi is right that you would not dare hold back stick when turning around if it were breezy.

On the narrow runways on my part of the world. there isn't room for the gyro simply to turn around by following the tow car. You have to stop and do a three-point turn, by pushing back with one foot while holding nosewheel deflection with the other foot on the steering bar. Or, you can put both feet on the ground and just pick up the gyro's nose with one hand and swing it right around. Pad the tow boom angles to avoid blisters from these lifts!

Note how long the initial slow-taxi phase is after hand-starting the blades. The pilot seems to have a good feel for this procedure, as no flapping is apparent.
 
Wow - pedestrians, low flying drone, a vehicle, wide well-marked pavement, all in the same runway environment . Not something I'm likely to see anywhere I fly!
 
After watching, I just have visions of being towed down a highway and passing a cop. And then wondering what kind of charges there would be? Of course from a practical stand point, power lines, which cross most roads fairly often, would be a problem, as well as road signs and other hazards.
 
If someone manages to register their gyro-glider as a trailer with their state's department of motor vehicle. The gyro-glider would be a legal trailer. However the pilot would most likely be cited for illegally riding in a trailer when being towed on a road.

Wayne
 
Around here you would probably also need brake lights and safety chains for the hitch.
 
In the New York Metro area, where I lived when I first encountered gyros, the Holy Grail was any paved but unopened stretch of Interstate highway. Certain members of our PRA chapter would tow their gyrogliders on these stretches. They got a whopping five minutes of flight time on each run! I didn't hear of anyone being kicked off or cited for this activity. Never tried it myself, though.
 
Interesting footage of a glider tow in Sweden. The aircraft seems to be accompanied by a drone, so we have a fairly close look all along the flight path.
Looking forward to the comments of the experts, anything peculiar about the rotor management at the start?
No. Just, no.
This is a new level of insane.
 
In reality it’s quite safe. The tow driver is the one in control. When my father took his last glider flight he and his buddy used 1000’ ft line and cut loose. The problem was when your learning on a glider you block the rudder off because it works backward because the nose is fixed. They unblocked it but when he landed there was a small x-wind and he had no idea how to cross control using the rudder and almost tipped over.
 
I wasn't there to observe, however one time at El Mirage, Ken Brock flew a gyroglider that was being towed by a Piper PA-18 Super Cub. Once at altitude, Ken released the tow rope and glided back down to the lakebed.

Wayne
 
I heard and read about that in the Rotorcraft Magazine. Ken was a dear family friend. He,Marie, Jim Eich came to our place quite a few times after Bensen Days and before Sun N Fun. He was living superhero. Told dad and I something I still remember to this day. “Anyone can jerk the controls on a gyro but, it takes skill to maneuver smoothly”. When I was flying people said I was always smooth.
 
I heard and read about that in the Rotorcraft Magazine. Ken was a dear family friend. He,Marie, Jim Eich came to our place quite a few times after Bensen Days and before Sun N Fun. He was living superhero. Told dad and I something I still remember to this day. “Anyone can jerk the controls on a gyro but, it takes skill to maneuver smoothly”. When I was flying people said I was always smooth.
I agree with you Mike. Both Ken and Marie were / and are wonderful. Marie still is in the present tense.

Wayne
 
The problem was when your learning on a glider you block the rudder off because it works backward because the nose is fixed. They unblocked it but when he landed there was a small x-wind and he had no idea how to cross control using the rudder and almost tipped over.
I don't understand this. I have been towed in a fixed wing glider by a pickup truck and a rope, by a powerful winch and a cable, and by a wide variety of airplanes working like 3-dimensional water skiing. Never had any reversal of rudder effect, and certainly no re-reversal when I released from tow in flight (whether using a nose hook or a center of gravity belly hook).

I would speculate that the rudder was blocked initially to simplify training by limiting temporarily the axes you have to worry about. If one completed gyroglider training with reverse effect rudder, and then moved to free flight with an engine and normal rudder, that would be one nasty transition.
 
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I wasn't there to observe, however one time at El Mirage, Ken Brock flew a gyroglider that was being towed by a Piper PA-18 Super Cub. Once at altitude, Ken released the tow rope and glided back down to the lakebed.

Wayne
The mismatch in comfortable speed range between the two could make that a challenging ride (a bit like when the early jets tried to aerial refuel behind prop tankers, only with the naturally faster craft in front).
 
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I don't understand this. I have been towed in a fixed wing glider by a pickup truck and a rope, by a powerful winch and a cable, and by a wide variety of airplanes working like 3-dimensional water skiing. Never had any reversal of rudder effect, and certainly no reversal when I released from tow in flight (whether using a nose hook or a center of gravity belly hook).

I would speculate that the rudder was blocked initially to simplify training by limiting temporarily the axes you have to worry about. If one completed gyroglider training with reverse effect rudder, and then moved to free flight with an engine and normal rudder, that would be one nasty transition.
I think what Mike is referring to is the change of yaw action as in relation to the rotation of the vertical axis location at the center of gravity. In all aircraft, rudder (or anti-torque) input moves the nose in the direction of input. While under tow, the location of the vertical rotational axis moves forward to the location of the tow rope connection. When rudder input is created, the nose wants to "swing" into the direction of input around the natural vertical rotational axis at the center of gravity, but cannot because of the tow rope. So the fuselage displaces itself (skids or fishtails) to the outside of the tow rope in relation to the intended directional change. Think of a fishtailing trailer at the tow hitch.

I first learned to fly gliders. My instructor had me perform "fishtails" while on tow by holding the wings level and inputting the rudder to demonstrate to me the physics of what I just described above.

Wayne
 
I understand your point, but the connection is not rigid as in a trailer hitch, because the tow rope can displace from side to side as the aircraft tracks left and right of the tow vehicle path. Glider pilots on aerotow can "box the wake" and hold a displaced position to the right using right rudder to resist the straightening pull of the rope. Nonetheless, push right rudder, and the aircraft will yaw right on tow or not, which was my point.
 
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