Helo hang glider????

tsheten8

Banned
Actually,I was thinking if this design could work..this is a light weight helo with a very limited engine power..it has a large rotor diameter since the engine power is limited..the engine will produce around 8 hp minimum..the engine is used to rotate the rotor but it wont be enough to lift the whole contraption..so I am thinking of taxiing or getting towed in order to increase the air velocity at the rotor to get the necessary lift needed..so my question is if this design will work..any advice would be greatly appreciated..
 

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brett s

Gold Supporter
What's your plan if/when the engine quits since that appears to be a fixed pitch main rotor?

If you don't have enough power to hover & are thinking about towing it airborne, how do you plan on landing it? And with only 8 hp you think you can maintain level flight on your own?

How do you plan on controlling the tail rotor pitch to compensate for power changes?
 

tsheten8

Banned
Well,thanks for checking on my post..actually,I have posted this simply to get some feedback from the fellow members..since powerful light weight engines are not available in my place,I was thinking if it could be powered by a 8 hp engine..yes,as you said I won't be able to sustain level flight because the engine power is limited..and since the main rotor is fixed pitch,i would literally fall from the sky in case of engine power cut out..and regarding the tail rotor,it will be fixed pitch too..but as the engine rpm increases so does the tail rotor rpm and produces more horizontal thrust to counter act torque effect..a lot of complicated things involved))..so I was thinking if I could do away with the engine and build something like this gyro hang glider..

http://www.madskies.com/

kindest regards
 

All_In

Gold Supporter
Hi Tsheten

I'm not enough of an expert in building let alone designing a gyroplane to offer an opinion based on anything but theory. Thanks to this forum I've learned so much and based solely on this knowledge (just a guess) I think with enough powder it will work, but these things only have a 4 to 1 glide ratio at best so they are draggy.
...and make sure the HS is large enough and it is as close to CLT as you can make it.

I never really like being the landing gear while flying hang gliders, one of the reasons I gave it up, but I think you have done well with your starting design.

I hope some of the pros will tell us both more.

Look luck with your dream, looks like fun to me.
 

tsheten8

Banned
Thank you very much All_In..Your comments much appreciated))..and you mean that with every 4 ft I descend I will travel forward by only 1 ft?..and what does CLT stand for?...I am asking this because I am not well versed in those terms in gyro world))..

kindest regards
 

All_In

Gold Supporter
Hi Tsheten
No the other way around. You move forward 4 feet forward for every 1 foot you lose, most fixed wing aircraft even airliners are 10 to 1 so that's the comparison. You need a stronger engine on a rotorcraft to lift and cruise the same weight.

Sorry, we do that a lot here. CLT 'Center Line Thrust'
There is HTL High thrust line, if your rotorcarft had this when you go from low to highest power setting your nose will move down and the pilot will need to bring it back up with the stick.
If it has a LTL 'Low thrust line' then when you apply full power the nose will pitch up again requiring the pilot to bring the pitch back to level flight.

With CLT 'Center Line Thrust' the nose will stay straight and level with all power changes and is pitch stable.

Now pilots learn to automatically correct the pitch, but with a hang rotorcraft especially I would want it to be CLT because if you found yourself in a zero 'G' event HTL could cut your tail off. Also in a rotorcraft you are never suppose to place yourself in a zero 'G' event but I've flown enough to know that wind and weather could put you in one but I believe this is a very rare chance without the pilots help.
 
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tsheten8

Banned
Thank you very much All_In..well,as you said,the rotor will offer a lot of drag and affect the forward speed of the gyro glider..in this case,I want to ask what the minimum power of the engine or the thrust from the propeller should be to improve the forward speed f the gyro in flight. NOTE:..I'll basically be running a steep hill with my engine running..

kindest regards
 

tsheten8

Banned
Will a 11 hp two stroke engine work fine to pull the gyro glider through the air though the drag from the main rotor will persist?..
 

brett s

Gold Supporter
The minimum power I've ever seen successfully used in an ultralight gyro (so under 500 lbs including pilot, ship, fuel) is about 40 hp (Rotax 447).
 

All_In

Gold Supporter
Hi Tsheten

No one knows and can tell you without knowing what blades you are going to use.

Once the pro's here know the blades (=lift/drag) and the approximate weight I believe there is a formula that you could use to calculate the HP you need.

So 30HP with very low weight = depends on the blades = maybe?

Maybe you should first ask what blades they would use on a design like this and then get the formula and you can calculate a closer approximation?

This is really not my area of expertise, here I'm the student.
 

tsheten8

Banned
Thank you very much,All_In and Rotor Rooter))..I have a russian friend and he's going to help me with obtaining the drawings from Mr. V.V. Shumekyo..

kindest regards
 
What advantage are you looking at with rotors, opposed to just using a hang gliding wing in the first place. You'll have trouble running with 30 hp. set of heavy rotors etc. You'll end up with wheels, in the end. One bad landing, hello plaster.
JD
 

tsheten8

Banned
well,all i really want to do is experience the thrill of gyro glider))..and yes,as you are mentioning i'll have trouble running with 30 hp motor..but i am thinking of running down slope or getting towed by a car and use the engine to prolong the forward movement of the glider..and i won't be making the main rotor rotate with the engine..the engine will be used only for powering the propeller,not the main rotor..

kindest regards
 
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cburg

Newbie
In the early days of motorized hang gliders the Soarmaster motor unit was mounted to the keel with the resulting high-thrust-line and old gliders with poor dive recovery many accidents resulted. Shortly afterwards the Gemini system was invented to lower the thrust line. Soon after the trike concept was invented and the low thrust-line and improved control authority of the engine/undercarriage/pilot shifting in unison have been the predominate approach, along with powered harnesses like the Doodlebug and Mosquito.

The Wasp is a 1970’s type wing (modified) with a refined Gemini system approach and still flying. Perhaps some of the engineering with the above mentioned approaches will aid your concept. To reacap the two approaches used 1.) fixed frame engine mounting, 2.) weight shiftable engine mounting.

Wasp
Wasp Wing twin engine ultralight hang glider, Keith Sharon's twin engine Wasp Wing. - YouTube
 

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tsheten8

Banned
Thank you very much for your kind information, cburg..))..but will the engine mounted on the nose of the gyro result in high thrust line?..I am thinking of engine and pilot moving in unison..

kindest regards
 

cburg

Newbie
I can’t think of any weight shiftable tractor (pull - from the nose) configurations, although I have considered push/pull on some previous twin engine trikes I’ve built, but instead made them contra-rotating push/push. In fact I’m building another Push/push twin now.

Foot lauchable is going to be very tough to do with a tractor, plus getting the static balance (neutral when you pick it up). You can achieve a neutral thrust-line.



Thank you very much for your kind information, cburg..))..but will the engine mounted on the nose of the gyro result in high thrust line?..I am thinking of engine and pilot moving in unison..

kindest regards
 
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