I've got some spare time this weekend so here is what I've been spending some of that time on.
A Modern Primary Glider, or MPG. For the purpose of this thread I'll defined an MPG as a basic training vehicle in the spirit of the old SG-38 primary gliders but built with more modern materials and complying with US part 103 regulations for a powered ultralight vehicle.
We have had plenty of threads here on HBA about how our aviation sport has been declining along with pages of speculation and opinions offered as to why. I don't want this thread to be a repeat of those. I'd like this thread to presume that the vehicle defined above is one possible, if only partial, solution and to explore the design and operation of such an entry level aircraft. If you don't think this approach is viable or is otherwise unworkable please offer your opinion, but back it up with some data or rational argument.
If there is enough interest in this subject then later the design and operation can be broken off into 2 different threads. For now let the discussion develop naturally. To start here is a list of attributes I have tentatively decided my particular project must incorporate – in no particular order:
The vehicle must be quickly and easily be broken down for road transport and be stow-able in a typical single stall US garage. All control linkages must be automatic or foolproof. Ideally the trailer could double as the launch winch.
The vehicle needs to be robust enough to survive students. Damage should be easy to repair, or cheap to replace the damaged part – preferably in the field with common tools.
Not only should the vehicle be robust, it must look sturdy and stylish to the average person.
It must provide adequate pilot protection for all expected crashes up to training speeds of around 35 MPH on basically smooth ground.
It needs a CG hook for winch launch. It's probably unlikely to have tow planes available that can tow slow enough to make aero-tow a practical option?
I'm thinking that modern brushless electric motors are the cleanest and simplest form of power and would be practical considering that the typical training flight is of short duration. Students would be issued their own battery packs which could be swapped quickly for each student. The battery could also be used as a form of movable ballast to accommodate different pilot weights.
The vehicle needs to be quickly configurable in the field for pilots between 90 and 225 pounds. Ballast for the lighter weight pilots could be added quickly with a couple of pins. Locating the main wheel such that a CG too far to the rear causes the plane to not rest on the nose could be a quick double check for acceptable CG location.
The vehicle should be capable of much higher performance than the old primary gliders. A L/D ratio of around 20 might possible and good enough for more advanced students?
An otherwise identical airplane could be constructed and equipped with a small internal combustion engine for sustained flight, registered as an experimental, and used as a transition aircraft for the most advanced students. This would allow for the time logged to count toward pilot certification.
It must be affordable. I've set aside $3K for materials, including battery pack and motor(s). I'm a pretty good scrounger.
That's the basics of what I'm thinking. I've got a lot of questions. Here are a few:
Would the American public accept a flying wing as a primary trainer? Would there be any significant problems for a student that had initial training in a flying wing transitioning to a standard glider or ultralight?
How does one design the location of a glider CG hook so that it is in the best position to maximize launch height? To make control by a student very easy? Would a bridle, like used on L-13's, be a better option.
I'm thinking that a yaw string, an AOA (angle of attack) and a voltmeter would be the only needed instruments, with an altimeter added for the advanced students?
I think a single main wheel would provide better training. Would the average American student accept a trainer that tipped onto it's wing tip?
Comments? Suggestions?
A Modern Primary Glider, or MPG. For the purpose of this thread I'll defined an MPG as a basic training vehicle in the spirit of the old SG-38 primary gliders but built with more modern materials and complying with US part 103 regulations for a powered ultralight vehicle.
We have had plenty of threads here on HBA about how our aviation sport has been declining along with pages of speculation and opinions offered as to why. I don't want this thread to be a repeat of those. I'd like this thread to presume that the vehicle defined above is one possible, if only partial, solution and to explore the design and operation of such an entry level aircraft. If you don't think this approach is viable or is otherwise unworkable please offer your opinion, but back it up with some data or rational argument.
If there is enough interest in this subject then later the design and operation can be broken off into 2 different threads. For now let the discussion develop naturally. To start here is a list of attributes I have tentatively decided my particular project must incorporate – in no particular order:
The vehicle must be quickly and easily be broken down for road transport and be stow-able in a typical single stall US garage. All control linkages must be automatic or foolproof. Ideally the trailer could double as the launch winch.
The vehicle needs to be robust enough to survive students. Damage should be easy to repair, or cheap to replace the damaged part – preferably in the field with common tools.
Not only should the vehicle be robust, it must look sturdy and stylish to the average person.
It must provide adequate pilot protection for all expected crashes up to training speeds of around 35 MPH on basically smooth ground.
It needs a CG hook for winch launch. It's probably unlikely to have tow planes available that can tow slow enough to make aero-tow a practical option?
I'm thinking that modern brushless electric motors are the cleanest and simplest form of power and would be practical considering that the typical training flight is of short duration. Students would be issued their own battery packs which could be swapped quickly for each student. The battery could also be used as a form of movable ballast to accommodate different pilot weights.
The vehicle needs to be quickly configurable in the field for pilots between 90 and 225 pounds. Ballast for the lighter weight pilots could be added quickly with a couple of pins. Locating the main wheel such that a CG too far to the rear causes the plane to not rest on the nose could be a quick double check for acceptable CG location.
The vehicle should be capable of much higher performance than the old primary gliders. A L/D ratio of around 20 might possible and good enough for more advanced students?
An otherwise identical airplane could be constructed and equipped with a small internal combustion engine for sustained flight, registered as an experimental, and used as a transition aircraft for the most advanced students. This would allow for the time logged to count toward pilot certification.
It must be affordable. I've set aside $3K for materials, including battery pack and motor(s). I'm a pretty good scrounger.
That's the basics of what I'm thinking. I've got a lot of questions. Here are a few:
Would the American public accept a flying wing as a primary trainer? Would there be any significant problems for a student that had initial training in a flying wing transitioning to a standard glider or ultralight?
How does one design the location of a glider CG hook so that it is in the best position to maximize launch height? To make control by a student very easy? Would a bridle, like used on L-13's, be a better option.
I'm thinking that a yaw string, an AOA (angle of attack) and a voltmeter would be the only needed instruments, with an altimeter added for the advanced students?
I think a single main wheel would provide better training. Would the average American student accept a trainer that tipped onto it's wing tip?
Comments? Suggestions?
