By Ed Burkhead
Chuck Scrivner is a private pilot ASEL, commercial glider pilot and USUA ultralight instructor with over 850 hours in the Challenger II including numberous hours of engine off soaring.
In thoroughly researching the FAA regulations, he has determined that there are NO regulatory limits, requiring specific characteristics, for experimental gliders. i.e. you don't have to have a certain wing span, aspect ratio, glide ratio, sink rate - none of those are specified for experimental gliders.
Chuck says, "I do not recommend that every aircraft be registered as a "motor glider". I suggest that most people fly aircraft that have at least some ability to soar. Like the Challenger............and a good many more U/L type 'floaters'
"I feel that by obtaining a Private Glider Certificate, the Pilot is better trained to "FLY THE AIRPLANE & less prone to the deadly stall/spin scenarios that we all read about an see on TV all the time. They understand L/D ratios, minimum sink, distance vs speed vs sink..........in head winds, tailwinds, in sink and lift."
(Side note on Private Pilot glider certificate advantages over Sport Pilot glider certificate from Chuck:
PP Glider = no night restriction, no altitude restriction, no airspace restrictions, may fly any type of motorized (jet, solar,) glider WITH in-flight adjustable prop, may fly complex, high performance.......But, most of all no weight restrictions.
Only a few 2 seat gliders meet the weight restrictions and speed restrictions for sport pilot. PP is Internationally recognized by ICOA. No medical required...even if one was denied previously.
To this end, Chuck has proven that it's possible to register apparently unlikely ultralight/Sport Pilot eligible models as gliders instead of ELSA. In the face of doubters, Chuck registered an MXII ultralight trainer with a pitiful glide ratio as a glider (self launch). Though it took some fuss, he got it through the FAA.
When the first couple of FAA staffers looked at his application, it was new ground to them. They found a reference which listed a ratio of wingspan to weight and tried to use that, claiming it's grounds for minimum airworthiness criteria - but they didn't read the document which was titled: "TYPE CERTIFICATION -- FIXED WING GLIDERS (SAILPLANES), INCLUDING POWERED GLIDERS." [emphasis added - Ed] The criteria for TYPE CERTIFICATION does not apply to experimental gliders of any type and there are no documents anywhere which give structural requirements or performance requirements for experimental gliders or motorgliders. (I can't fault those guys for not reading all the document carefully - it's written in FAA regulatory bureaucrat-ese but it's very clear that it does not apply to experimental aircraft - see below.)
The documents related to this are referenced below as an extreme example of an aircraft with low glide ratio but which can, nevertheless, do ridge gliding and soar with a really good thermal. Another example of an extreme experimental glider is SpaceShip One, the winner of the X-Prize for first civilian spacecraft.
Any plane that's a good glider should go through the system much more easily.
For example, I (Ed Burkhead) bought my Challenger II long wing kit explicitly because it was advertised and is capable of being flown as a glider. It can soar on good thermally days due to its fairly low sink rate and tight turning ability and low stall speed which allow it to stay in the thermals. During building, I've made choices of wing, wing fabric, instruments and options to enhance the ability to glide and soar.
Caveat: If you register your aircraft as a glider, it will always be a glider. The FAA won't allow that particular aircraft to be registered as another kind of aircraft. Once registered as a glider, future pilots will have to have a glider rating. (The only exception would be to disassemble it to a truckload of spare parts, sell the parts, then a buyer could build a "new" aircraft using some of the parts.)
This is the document so often cited as a "block"
to certifying our gliders. Please read it carefully and read
the title, the purpose (paragraph 1), and discussion (paragraph 6) to
confirm that it refers only to type certification.
Chuck's documents and information:
By Chuck Scrivner