[KaiMartin]

Paper: PHOENIX A Polyester-Film Inflatable Man-Powered Aircraft by F.E. To
http://aerosociety.com/Assets/Docs/About_us/HPAG/Papers/HP_phoenix.pdf

This was a VERY interesting read!
An inflatable 30 span human powered wing is an exceptional feat. The narrative feels like a recipe to build your own, possibly improved version.
At the end of the article two follow-up versions are mentioned. Do you happen to know if these also succeeded to fly?

---<)kaimartin(>---

[KaiMartin]

Birds have far more control of their wings and tail than we will ever have

True. But human constructions can pull potentially some tricks which no bird has evolved. A major example are the various flaps at the trailing edge. Quill feathers have some extraordinary properties. But they cannot actively bend.

The Wright's aircraft was unstable making it difficult to fly requiring constant input from the pilot.

I am not so sure, dynamic stabilization is necessarily difficult for the pilot. After all, we humans can ride bikes nearly effortless. Sure, the famous on board film of the Wright flyer in France does look quite stressful to the pilot. But this may be an effect of the parameters of this particular configuration.

Modern fighter jets are also made unstable and can only fly with the aid of computer controlled systems.

The required reaction times decrease significantly at higher speeds. Once they are below a certain level, human pilots are clearly out of the game. But hang gliders are supposed to go slow. So there may be enough headroom for dynamic stabilization. Up to now this is little more than speculation. But I will try to get a definitive answer whether or not dynamic pitch stabilization by the pilot can be a viable concept. Will keep you posted...

Your proposed tail lock could work but requires additional pilot input at a critical stage of the flight.

Fair enough. The unlock-trigger should be positioned in a way that it activates specifically on push-out. Imagine a lever at the down-rights where the push automatically also unlocks the tail.

---<)kaimartin(>---

[ARP]

Kai,

Fred has not mentioned any further HPAs built this way but I could ask him. There is an E-book now available written by one of the pilots. I will find the details and post.

I have flown a divergent hang glider so it is possible to do but it needs constant attention as, once passed a certain point, weight shift will not retrieve the situation.

After take off the tail would need to be pulled down to its "in-flight angle" and then locked adding to the complexity of the glider.

My reaction time is probably not as good as it was but I can still fly a trike reasonably well. To test unknown devices in flight will have its risks and require good reactions. Try it out on models first before committing life and limb in full size testing.

Tony

[ARP]

Article on inflatable aircraft including the Phoenix HPA :- http://bayourenaissanceman.blogspot.co. ... craft.html

E-book:- Phoenix Reborn - How I flew the world's slowest aeroplane. by Ian Parker. Available on Amazon KDP; search on title or authors name.

[KaiMartin]

Moin Arp.

I have flown a divergent hang glider so it is possible to do

Was it a publicly known model? The valkyrie perhaps?

but it needs constant attention as, once passed a certain point, weight shift will not retrieve the situation.

My thoughts are mainly a result of contemplating why riding a bike comes so easy to us humans:
1) Pitch instability of a wing and roll instability of a bike are quite similar. Both provide a torque that gets worse the farther away the system is from equilibrium. This sounds like bad news. But it is actually good. For it also means, the torque reduces to arbitrarily small values when close to balance.
2) We use the vestibular system and visible clues to detect any beginning fall. For this to work most efficiently, the orientation of the pilot should be fixed relative to the wing. Dangling from from a hang strap is probably less than optimal.
3) Controls should be sensitive. On the bike you can turn the handle by at least 90°. But only a few degrees are needed to keep us from falling.
4) Controls should be as effortless as possible. On the bike, next to no muscles are needed to operate the handle.

Sensitivity and effortlessness are kind of conflicting. Pulleys or lever action to improve one will also worsen the other. I try to come up with ways to let the legs do the work.

After take off the tail would need to be pulled down to its "in-flight angle" and then locked adding to the complexity of the glider.

Fair enough.Unstable during launch is probably not a good idea. I still like the idea to make a pitch stable glider unstable on landing.

Try it out on models first before committing life and limb in full size testing.

A good amount of training on a ground simulator will probably be necessary to train reflexes. Actually, a simulator will help me to see whether or not the whole idea is sound or just a case of wishful day-dreaming.

---<)kaimartin(>---

[JoeF]

Good progress guys.
==============================
Richard Miller mentions Taylor McDaniel in the Miller book of 1967: Without Visible Means of Support.
Here is the McDaniel patent:
https://www.google.com/patents/US1905298
Filed: Aug 13, 1930
===============================

Using lessons from historical examples, advanced materials, tensairity, bladder-pressed veneer,
and strategic use of some non-inflated parts, there are, in my estimation, some fun HGs to be designed,
made, and used. I keep in mind niche uses where placard limits need only meet the niche use, not more.
Mild Dockweiler Handy Dandy HG can be very different from XC mountain HG.

[Frank Colver]

I would be willing to bet that Vectran is being used in some of the government funded inflatable UAV development. The US government already uses it for the Mexican border surveillance balloons.

It does only come with a black polyurethane coating. The black color protects the highly UV sensitive Kevlar cloth. This ,makes for bigger temp changes going into and out of the sunlight.

Frank

[JoeF]

Exploring Vectran and UV looks like something to continue.

==========================================
Frank, you mentioned Miller and truss interest. Here is truss to the nth power:

[Frank Colver]

Miller would have loved that!

Frank

[ARP]

Kai,

"Was it a publicly known model? The valkyrie perhaps?" No just one of my early Rogallo types. It had no top rigging which meant the bottom rigging was slack at take off. The slack was taken up on take off but it then held the keel tube too low causing a nose down pitch moment. It could be flown like that but my brother did end up breaking his leg on it after losing control.

I am a check pilot for the BMAA which involves flying microlights after an inspector has checked the aircraft for its yearly permit to fly cert. One of the tests is to see if the aircraft will pull out of a dive automatically. The feed back on the control bar gives a good indication if the aircraft is divergent. Most are pitch positive and recover well but I have had one that failed and had to recover manually. When doing this I make sure the back up parachute is at hand if all else fails.

Tony