View Full Version : Self-contained gyro trainer…..
08-09-2010, 07:18 AM
Just a thought…..
This may be dumb but I was wondering about the feasibility of PRA Chapter's putting together a gyro-gliding trainer that was self-contained….requiring no towing vehicle. I'm not sure of the power required to do this but perhaps it would be possible to direct a large shrouded prop's blast, far enough from a gyro rotor to cover its diameter and cause it to auto-rotate to normal rrpm's.
If an engine and prop were mounted to a turntable and a rope attached to the table periphery (in line with the prop shaft) and going out perhaps 20' to the gyro, would allow the gyro to travel 360° in no wind conditions. There could be stops to limit table rotation with wind over a certain amount. The gyro would need wheels that swivel toward any side load. The gyro could only climb as high as the prop blast would allow. Jake could throw this together in no time ;).
The engine and prop would be aft of the turntable (like a playground merry-go-round) center, in line with the rope.
08-09-2010, 07:32 AM
Ed, great idea! Have you seen this, a little more high tech, but same principal... Dailymotion - Robinson R22 Real Helicopter Flight Simulator - a Auto-Moto video (http://www.dailymotion.com/video/x7gus5_robinson-r22-real-helicopter-flight_auto)
08-09-2010, 07:38 AM
kind of like a gyro wind tunnel.
08-09-2010, 07:41 AM
No Mike...I haven't seen that. The problem with that scheme is that there would be no true seat of the pants feel ;).
08-09-2010, 07:46 AM
Yes Tim, I guess it would be like a wind tunnel. What we need is someone like Chuck to figure if it is doable with reasonable power (like from an old car engine).
The turntable wouldn't need to be round....it could have a triangle shape.
08-09-2010, 08:01 AM
This person use to manufacturer Air Commander hovercraft, and now makes the super fans. Just a thought... http://www.hovercraftdepot.com/5.html
08-09-2010, 10:34 AM
I don't understand the need for the turntable , I have done a shakedown test flight of a new gyro tied behind a DHC 3 otter that was also tied down and it didn't take near full power for liftoff, I only stayed up for a few minuits as it was very cold which is why I could not get the engine on the gyro started for a normal test flight. The otter used a 600 HP geared radial engine that turned a very large prop, this was not something that I planed on doing, I just happened to be trying to get the engine started when the friend who flew the otter was getting ready to take off and since he had deluted his engine the night before so it would start he had to sit at a high idle for a while and slowy increase power to evaporate the fuel out of his oil and I had heard of bensen flying a gyro behind the prop of a large autogyro.
I think that a 350 V8 belted to a large prop on a trailer with water tanks for ballest could fly a glider as long as there was someone to pay for the gas. it would be cheaper to tow the glider with a car
08-09-2010, 12:04 PM
Mike: That would surely be a great way to go but I was hoping for a much less expensive way….perhaps just a shrouded (like a PPG) wood or aluminum prop driven by a car engine with belt or gear reduction.
Norman: With a turntable, the gyro will always be directly behind and centered in the prop blast….otherwise with a stationary prop the gyro could leave the centered airflow and cause rotor balance and rrpm problems. I certainly could be wrong but I would think a smaller hp engine could make the rotor happy from ~20' away….then again I could be all-wet.
08-09-2010, 12:34 PM
A really quick sketch I what I mean....
08-09-2010, 12:41 PM
Great idea if someone could get it to work. Could be used in places where there isn't long runways or open areas where a tow vehicle could not be used.
08-09-2010, 12:45 PM
What happens when the engine fails and you are up in the air 10'? When I was training, my worst landing was dropping in from about 3' and not adding power. Talk about knock your fillings out. I couldn't imagine that from 10'
08-09-2010, 01:00 PM
I doubt that you could go that high for very long because you would be out of the blast cone....unless the prop thrust line also followed the glider. We could also use an American engine ;).
08-09-2010, 01:26 PM
since you can't climb higher than the prop blast getting to high won't be a problem and it may be better to use 4 six foot props instead of 1 large one, this way you will stay low and it will not be so easy to scoot outside the airstream, this sounds like something that will have to be experimented with. There is another training device that works well to break the habit of flying behind the power curve with a glider, the air sled but it needs lots of space like where I am or dry lake, the only control needed is a throttle and a break away kill switch just in case of a disconnect, steering is done with the glider. I think if these had been used between the glider and powered gyro there would have been a lot less accidents in the teach your self days.
08-09-2010, 02:00 PM
I look at a glider as a way to become proficient at controlling the gyro for a constant wheel height of say 3'. The engine speed would be varied so the pilot would need to correct the pitch to stay at that height. By lowering the speed to a point where the gyro would be difficult to maintain wheel height, may be a good exercise for behind the power curve. Perhaps the engine could be remotely controlled so the pilot could try/practice different power settings…..
08-09-2010, 05:56 PM
Ed, I like where you're headed with this! It seems everything comes back around eventually, so with a little modern technology, might be a great training aid!
08-09-2010, 07:07 PM
Sounds like a wind tunnel Ed. I grasp your idea. When you are as old as I am we used the same idea.
Once the gyro glider was cobbled together we discovered that a whole day's wages could buy a long piece of stretchy nylon rope from Army surplus. Wait for the high winds to come and tie the gyro to a hydro pole or telephone pole .
Never did get airborne. Never did get a bill from hydro or telephone for anchoring to their pole. But I did dream about flicking a switch to turn on a big fan to blow lots of air. A guy could fly all day and still be anchored to the ground.
Modern day gyrocopters with a screaming engine and a small fan pushing behind the seat of the contraption usurped my dreams.
What bothered me most was I never got to prove my theory that the significant stretch and tension of the infinitely long pure nylon rope would adsorb and compensate for the changing wind speeds and gusts.
I think the nylon rope was braided together from WW2 parachute cords. All the good things were invented in the 1940's.
Including cell phone technology that eventually replaced all the telephone poles. Beautiful Hollywood actress Hedy Lamar was instrumental in discovering the technology that our modern cell phones operate on. That is why we no longer have telephone poles all over the country. Gyro glider have nothing to anchor to on the prairies :)
Some actresses do have brains.
I was not around in the 1940"s but I admire the innovation of those that were..
08-10-2010, 07:52 AM
Gosh Arnie, it would be wonderful if a variable speed electric motor could power this thing and we would just need to throw a switch! Sigh…..would probably cost a small fortune though. BTW, we did use a nylon 100' tow rope, and it did dampen the towing extremes.
Unfortunately, I have seen the forties and have been wishing for years that I was still my exemplary self at 24…..and knowing what I know now of course ;).
08-10-2010, 08:04 AM
I am just reading Ed :) (so that you know LOL)
08-10-2010, 10:44 AM
Glad you are Gabi....this is very important reading for those unaware of these rotor blade thingies ;)....unless you are a heli CFI....
As regards to power, something I should have said is I thought of using vanes at the prop to direct most air-flow at the middle 1/3 of each blade, as though the blades were always perpendicular to the rope. The middle 1/3 of each blade is where most of the autorotative force is created. I think by directing the air-flow there, the power required would be reduced because the airflow in other areas is not as important for autorotation and in fact would cause more rotor drag at the outer lifting 1/3 of the blades…..then again, I may be all wet…..
08-10-2010, 11:21 AM
I would think the proposals so far listed would be far more hazardous, and expensive, than just operating a standard gyroglider towed by a car.
1. an adequate spread of stable, constant speed air is best supplied by God or a towcar.
2. Anyone who has kited on an inadequate, variable strength or turbulent breeze will
tell you how dangerous it is. I have personally witnessed two attempts at this, and
it was truly frightening.
3. Gyro wheels dont work sideways. Touchdown with any sideways motion on a hard
surface and over you go.
This is a solution in search of a problem.
Gyrogliding is fairly easy, and fairly safe, if approached correctly, and with patience.
Maybe with a turntable we get a nice and stable airflow?
Maybe not a true gyroglider, but it might be a great toy as well as a trainer to some degree.
For sure a nice problem from Ed ;-)
Maybe it inevitable will work - only depending on how much wind we need.
08-10-2010, 01:05 PM
You are correct Fergus, this idea would be more expensive than using a tow-car. Finding a place to tow a glider is becoming more difficult, most airports won't allow it and the cops frown if one uses a back road. I have watched a guy fly a glider for over an hour each time we had a cyclone roar in off the ocean, safely grinning the whole time. The glider wheels do need to swivel on what I proposed. Perhaps we can't realistically produce enough 40 mph air volume to make this work…but if we can, it then MAY be worth a try. I feel a glider is a valuable first step in training and will bring more people into this sport.
Like Jens alluded to, all we need is someone who would know how to calculate the air-flow and power...to see if this is feasible. It's easy....just not for me ;).
08-10-2010, 01:39 PM
Forget airfields, unless derelict or very quiet.. They are often a poor location for gyrogliding, which is difficult to mix in with other runway activity.
Find a flat grass field of at least 2000ft ( the longer the better, but 2000 will do fine ).
If you can drive it comfortably in the car at 50 mph it should be smooth enough.
If its a bit rough, drive it with the car til its smooth enough
Fly early in the morning if possible, lift is much better then, wind is less, generally.
Make sure the tow driver is properly briefed, better still if the driver is a gyro-head.
America is a big country, you can do it.
08-10-2010, 03:26 PM
the easy to test this is to use two or three airboats to provide prop blast.
You need: 1 gyroglider, 1 gyrocopter and 2 pilots.
Wind should be about 80% of what is needed for gyrokiting.
Tie down your gyrocopter just in front of where the tow end is fixed to mother earth.
Take your sets gentlemen!
Ad power to the prop :eek: :plane:
Should give an idear wether or not 'ED's invention' is possible, worthwhile, safe etc..
08-11-2010, 10:31 AM
A little more elaborate setup would work as well. And Mentone is a good place to install this setup. Tow gliders were launched by the use of motors with winch setups which could be installed at both ends of the runway at Mentone with a switching system to change the direction of travel of the tow apparatus from one direction to the other to tow in either direction.
The anchor points could be centerline at both ends of the runway, and when not in use the tow line could be moved off the runway to the side at both ends to make way for regular traffic use.
The camping setups would allow for sessions to be completed while staying on the grounds during training. I know I would make the trip and stay the course if it was available
08-11-2010, 05:14 PM
What about a small go-ped motor on the gyro ?
If I understand correctly 2-3 hp permenant drive to the head will reduce the power need from the fan/winch.
Leave it off for the initial launches to teach rotor control and spin up, then fit it for almost immediate takeoff and longer flights.
08-11-2010, 06:48 PM
I was hoping someone could run some numbers to find if using a prop blast is a feasible mode of power for this glider. As Jens said in #25, someone with a glider and a powered gyro could determine if this scheme would work, although it may take ~100 hp engine. As Karl said, an auxiliary engine/motor may increase the odds of this working. Anyway of using gliders would be helpful, whether by this or a car or Jim's winch system. I just thought the fewer people required along with the smallest space requirement may provide more interest and use.
Gyrogliding is a proven thing for fun and for single and dual training of new pilots.
Where possible and brought on, it will receive much appreciation – I think.
Gyrokiting is quite another game, and NOT for new pilots – I think.
Gyrokiting on big noisy energy consuming windmachines is MUCH TOO MUCH!
Gyrokiting on partly natural wind and a windmachine is still TOO MUCH!
Gyrokiting on partly natural wind, partly an electric powered gyrokiter and partly electric powered windmachine(s) is still MUCH!
Does the last combination have a chance?
10-28-2010, 09:15 PM
you are proposing what is in the picture below. It's the Fa330 Bachstelze in the wind tunnel of Chalais Meudon, which was used for pilot training in 1941/42. So it can be done, but you need a pretty massive fan to generate the required air stream, your motto seems to be "Think Big".;-)
I agree with Jens that this is overkill. Attach two small electric motors to the rotorblades about one third radius away from the hub and feed these through the tether. You could also add a propeller in front of the pilot to give him the feel of the slip stream. To compensate for the propeller thrust and keep the tether taught you simply incline the rotor a bit further backwards. The hard part here is the sensors and the control logic you need to keep the pilot from getting into trouble, but that's small compared to a 25+ feet fan generating a 30+ knot air stream. The big advantage is that you can run this thing off the main in your home and fly in your back yard
10-29-2010, 06:51 AM
If ya want wind blast,a surplus jet turbine,find it's balance point so the tow rope can pivot the exhaust blast at the Gyro at all times. long steel cable and better like the smell of kero. but sorry I think dual training is still cheaper then these Idea.
I mean there are all kind of huge aircraft engines and props that could create enough wind blast, like the engine from a old war bird like a B17 or some other huge transport. but for what the engine and prop would cost not to mention the fuel burn you can travel at an already established gyro CFI.
(Wheels should be changed to swirl type)
But actually it would be much simpler, to bolt directly on to the rotor head, a 15 hp engine with redrive, centrifugal clutch, electric starter and muffler - only 10-12 kg / 22-30 lb.
Battery and fuel tank on mast.
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