For those with an interest in the Goodyear inflatoplane.

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
2,967
Location
Rochester, NY, USA
The Inflatoplane was intended to self rescue downed pilots. I've seen gyro copters, balloons, and even the awesome ride of the Fulton system.

A "square" ram-air chute and a sustainer motor wouldn't be THAT hard to integrate into an ejection seat. My back isn't up to that or I'd love to test it. Butler was ahead of the curve there.
 

edwisch

Well-Known Member
Joined
Aug 11, 2020
Messages
86
The Inflatoplane apparently had atrocious flying qualities. Not to say that couldn't be improved upon, but...
 

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
2,967
Location
Rochester, NY, USA
Since it's unlikely that Goodyear will resume production of the Inflatoplane or the F2G, I wouldn't worry much about possible poor performance.

It's not the only inflatable. The WhoopyFly is fairly low AR and as a hang glider, is past obsolete, but there is potential in the concept.


Insert Here Rant on paraglider technology and why I haven't been flying them the last century... or whenever they started, which will get some argument.

We were flying "regular" skydiving "squares" off ski slopes not long after they were commercially available for jumping. 3 to 1 glide ( more or less ) and a sink rate that takes Boomer thermals to stay up ( translation, your passengers are very unhappy in your Cub ) we just did so as a novelty. Our hang gliders, although heavier and more trouble to transport, were so much better performing.

Naturally by increasing the AR and eliminating the sliders and other open in free fall features, the paraglider has evolved over the decades into quite the nice flying machine. And back-pack power opened that up for flatlanders and then slalom racing, and....

But I don't fly them? 2 reasons, both subjective and personal. And local terrain related... lots of trees. Lots. Few open grassy slopes.

1. The wing can collapse in turbulence. Yes, it straightens itself back out pretty darn fast, but since a lot of my flying is close to the ridge, I wasn't fond of that aspect. A 20 foot drop is no big deal at 1000 feet, but has a high pucker factor when you're 30 feet over tree tops, and just a few wing spans away from trees to the side. Besides, my glider at the time had better glide and speed... ( and the new Paragliders are better than it was )

The skill level rating system is basically based on how well you can manage the wing to avoid collapses, and recover from them.

2. i didn't like the soft connection to the wing, and the pendulum swings in maneuvers. That's personal preference.

But by golly, you can get a great soaring sink rate, and a glide angle useful in the real world, if you aren't expecting sailplane performance. And you can carry the unpowered paragliders on your back and walk or bicycle with one. The latest rigs are under 10 Kilos with wing/harness/pack/reserve parachute/and a warm jacket so you can Hike & Fly the Alps if you are in good shape and have the skills. Add a paramotor and I'd want a motorcycle instead of a bicycle, but a minivan or hatchback is more than big enough to go flying.

But there isn't a lot of demand here for that level of flying, ( and sewn fabric construction is an acquired skill set ) and then there's us guys with old legs and backs...

So, if you cross breed the trike, the WhoopyFly inflatable ( which would be considered a Semi-rigid if an airship ) with a carbon fiber main spar, and higher AR and better airfoils as seen on today's paragliders, and you'd have a pretty decent performing highly portable flying thing.
 

Bille Floyd

Well-Known Member
Joined
Sep 26, 2019
Messages
517
...

Insert Here Rant on paraglider technology and why I haven't been flying them the last century... or whenever they started, which will get some argument.
...
Learned to PG in 1989 ; spent 3 days, on the sand dunes 1/2
way to Ensenada ,in Baja mexico, learning to fly PG, from 3 girls
from Austria, who didn't like wearing clothes ! :)
Was Really Fun !!!

Fast forward to 2019, at CSS , in San Bernardino.
Was 1/2 way up a 3500 ft vertical Mt , tracking a thermal , maybe
less than 100' AGL, and the entire Right side
of my PG, just folded under. Did the necessary recovery and continued
up the ridge ; but remember saying to myself :
"My Rigid-wing Exxtacy ; it never does that " !!!!

I've questioned my sanity, when flying PG, ever since ; but
i still do it . :(
Should i get therapy ?

Bille
 

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
2,967
Location
Rochester, NY, USA
Nah. Just consider me cowardly. ;)

My SCA friends consider me a bit of a safety nut, volunteer first aid & coach/referee while also doing the martial ( fighting ) side. Since the entire group is considered odd by mundane, you have to apply a sliding scale. See note 1

Ditto Aviation, which I describe as a hierarchy of "you're crazy!" With the gliders, hang gliders, skydivers, base jumpers, etc. ... Looking "down" on the tiers below, mostly in a polite "never catch me doing..." way, and not politely said out loud. ( and aviators like medical folk tend towards accuracy over manners )

We could have endless discussion on the ratings ... how do you measure the risk level of low altitude stunting vs. Racing vs. ???? Better to just laugh at each other.

Inflatable airplane, by definition is up there on the crazy scale. But some combinations of fabric wings held by ribs battens and internal air pressure do work well.



Note1
best example is perhaps siege engines. In full contact armored combat, we get bruises. To let people participate in big battles without risking getting run over by a mob of running heavy war beasts with poor vision, ( helmets! ) we have combat archery with low power bows & bird blunts. ( if a heavy fighter gets close, you surrender)

And of course, we have catapults etc.

I'll add everyone on the field has protective gear. Archers and siege crews can get shot, but we don't hit them with 6 ft pole arms.

Since in the real world field artillery tosses melon sized rocks that will demolish a house or human, armor or not, we use "safer" projectiles. Like a duct taped wrapped tetrahedron of tennis balls. Depending upon velocity, that hits from noticeable, to knock down. It's too hard to enforce velocity limits, ( mostly positioning the measuring gear & not wrecking it ) so one rule in some areas is Classical Roman.

Roman Bridge builders sat in a boat under the new bridge while they had the ribbon cutting and then marched a Legion of loaded troops over. Then the big party. ( reduced the need to pay incompetent contractors)

Ditto if you want to build & use artillery ( catapult, ballista, sling ) you have to be willing to armor up and take a shot at appropriate range. It's an attempt to be more "fun" than nerf weapons & not hurt ourselves too much.

In aviation, we solo test fly. Same morality.

So you can plug "old martial arts marshal" into your context field. ;)
 
Last edited:

reo12

Active Member
Joined
Jan 15, 2021
Messages
38
Learned to PG in 1989 ; spent 3 days, on the sand dunes 1/2
way to Ensenada ,in Baja mexico, learning to fly PG, from 3 girls
from Austria, who didn't like wearing clothes ! :)
Was Really Fun !!!

Fast forward to 2019, at CSS , in San Bernardino.
Was 1/2 way up a 3500 ft vertical Mt , tracking a thermal , maybe
less than 100' AGL, and the entire Right side
of my PG, just folded under. Did the necessary recovery and continued
up the ridge ; but remember saying to myself :
"My Rigid-wing Exxtacy ; it never does that " !!!!

I've questioned my sanity, when flying PG, ever since ; but
i still do it . :(
Should i get therapy ?

Bille
I watched chutes of various types fly at our competitions back in the 90's and early 2000's. I saw partially inflated chutes and chutes turn strange shapes when wind shear moved through. I always had a bit of a pucker about chutes as a result. Then I think of the loss of Hank and Carole Austin and wonder what exactly happened with their chute. Did it suffer a partial collapse?
 

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
2,967
Location
Rochester, NY, USA
I've been looking at the current tech in paragliders and power kites, and there's interesting trends in adding stiffeners, battens, ribs, sticks, and other cross mutated aviation/sailing/hang gliding/surfing nomenclature.

The Leading Edge Inflatable kites use a sewn wing, Single Surface, of dacron and light rip stop synthetics, with shaped pockets for polyurethane bladders. From bicycles I learned the material has a lifespan, but is light, strong, and reliable if it's maintained with some OCD to prevent wrinkles. The kite geometry is low to low medium AR, curved leading edge, and a highly variable # of ribs. ( 0-7?) The suspension lines attach at the tips, giving a high anhedral "C" to "(" shape to the wing. Minimum bridle to control twist and angle of attack.

Over on the para foil side, there is sophisticated internal structure, variable AOA, and for ultimate lightness in kites and paragliders/paramotors, mostly Single Surface, with a ram air leading edge like the "regular" double surface parafoils.

Hybrids of those designs could be very practical, for a modern Inflatoplane. My gut tells me that aluminium or carbon fiber tubes & spars are lighter or more reliable for details like tail booms. ( than an inflated fuselage )

Translating suspension line supported flying wings to semi-rigid conventional control and pilot position is a non trivial challenge. Pitch stability and control especially.

A Demoiselle style cockpit/fuselage with inflatable wings?
 

Bille Floyd

Well-Known Member
Joined
Sep 26, 2019
Messages
517
100% agree, that a LEI kite, could use the technology of a modern Inflatoplane ;
but the wind-range would be so huge, that one or two kites, would cover most of
the needs for the average person, and companies are making more wind specific
kites so they can sell more of them. I already asked a manufacture about it.
Could start a new company ; I think the idea would be a Good one !!

For use in a PG; only downside i could see would be internal
pressure increasing, as ya go Up in a thermal maybe ?

Bille
 

Gregory Perkins

Well-Known Member
Joined
May 25, 2019
Messages
140
Location
Atlanta
Jim Bede was the earliest that I know of to create an inflatable aerodynamic lift generating shaped wing paraglider type device. It was retangular in shape as opposed to the banana curve shape of todays paragliders.
 

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
2,967
Location
Rochester, NY, USA
For use in a PG; only downside i could see would be internal
pressure increasing, as ya go Up in a thermal maybe ?
My trainer kite ( a HQ Hydra 420 ) has velcro closed trailing edge openings at the wing tips to let water.sand/dirt/snow out as you use it. It's the bottom tier tech, and the last time I flew it I got about 40 pounds of water trapped in the silly thing, and was flying it sluggishly, about 30 feet up, with a thin stream of water drizzling onto passing speedboats. :) Some models have magnet closed "blow out" sections in the trailing edge to prevent the wing from tearing itself apart from the pressure spike when you slam it nose first into the water or ground. So there are simple methods to keep from popping the parafoil designs. And since winter jump boots have had pressure relief valves since at least the Korean War, even the LEI designs can be made idiot/altitude change resistant. In Inflatable designs, the smaller the tube, the higher pressure needed to maintain shape. So sizing the inflatable sections and the relief valves is fairly simple engineering.

The harder part, to me, is getting rid of the suspension lines and getting reasonable load paths to support pilot ( and engine ).

The WhoopyFly uses a rigid aluminum spar, but LEI style higher pressure tubes should enable the same thing.

This is one of those cases where "Purity" of design forces compromises in performance. The less "hardware" you use the more complex and heavy the Soft Stuff has to be.
 

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
2,967
Location
Rochester, NY, USA
Jim Bede was the earliest that I know of to create an inflatable aerodynamic lift generating shaped wing paraglider type device. It was retangular in shape as opposed to the banana curve shape of todays paragliders.
Parafoil - Wikipedia
1966 patent, Domina Jalbert

I was by NO MEANS the first to fly a skydiving ram air parachute off a slope, but we were doing that in 1979 at Bristol Mountain ( NY ) after reading about it being done in France 1978, who read about it being done in England, 4-5 years before, and.... I was flying single surface Rogallo & "Sled" soft gliders off slopes in 1973. Based on designs NASA was experimenting with for Gemini. ( Not knowing about the work done in Europe ) And I'm SURE I wasn't the first to do that either. I recall the Bede experiments, but can't find a date, and I only read about Bede's work after I'd already moved "up" to wood & plastic, then Aluminum and Dacron Rogallos. So I have doubts Jim was first, but do not claim to have beat him. ;)

It's sometimes very hard to document who was First in Aviation.

I'm utterly convinced the Wright brothers were first to have the 3 axis control & powered flight that they could and did repeat. The Infamous Smithsonian Feud with the Wrights over the Langley tandem wing tossed into the river has been muddled by Glen Curtis who was trying to fight patent claims, and Serious Institutional Ego.

I will make the claim to being first to beat a suspension from High School for flying a home made glider off the Gymnasium by showing that there was no written rule against it, in 1974. Feel free to puncture that ego balloon.

Funny enough, in 1977 I had an echo of that when my friends got stopped towing a Para-Commander parachute behind a van @ Hamlin Beach park. We used to do guerilla para-towing wherever we could, and used to tow up to altitude, then cut loose at the upper end, to practice spot landings. We'd flow about 3 times one day at the park, when the Park Police arrived, and stopped us. "You can't Skydive here!" We protested we weren't. No Hang gliding! Nope, not doing that either. ( hoping they wouldn't see the folded glider on my van a few hundred yards away ) The State Police were called for backup. Soon 4 police cars were clustered and 6 cops were arguing over what to charge us with, & jurisdiction, literally reading the rules book on the trunk of the police car. "No, they aren't doing that, Hmm, how about..."

As they argued, we packed up the chute & lines and when they were at the yelling stage, quietly drove away, up to the parking lot on the hill where we could watch. After another 15 minutes, One of the State Police made a Triumphant gesture, A Decision Had Been Made! and then they looked around... then 4 police cars raced off in 4 different directions to apprehend the miscreants... We never learned what they chose to charge us with.
 

Dillpickle

Well-Known Member
Joined
May 3, 2014
Messages
186
Location
Piny Woods, Tx
[QUOTE="Bille Floyd, ...
Learned to PG...
Was 1/2 wayupa 3500 ft vertical Mt , tracking a thermal , maybe
less than 100' AGL, and the entire Right side
of my PG, just folded under. Did the necessary recovery and continued
up the ridge ; but remember saying to myself :
"My Rigid-wing Exxtacy ; it never does that " !!!!
I've questioned my sanity, when flying PG, ever since ; but
i still do it . :(
Should i get therapy ?
Bille
[/QUOTE

A buddy of mine, hang glider pilot and instructor for decades, one of the high time commercial hang glider pilots, learned to fly PG, bought high quality. After two canopy collapses, in one flight, he landed safely. The next day he cut every line on his PG. He told me that he couldn't feel comfortable selling something so dangerous. This from a guy running off some pretty sketchy hillsides around the continental US, in some pretty high performance bits of equipment.
 

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
2,967
Location
Rochester, NY, USA
One comment on my previous post re: relief valves.

They CAN fail. In fact, one Goodyear Inflatoplane had a valve jam shut, and with the engine mounted air pump designed to keep the plane inflated, even with a few bullet holes, risk being away, split a seam due to over pressure, dunking the plane & pilot into the bay.

However, the fatal crash of one was apparently from a control cable coming off it's pulley & jamming. Which is a thing many of us need to look out for.


 

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
2,967
Location
Rochester, NY, USA
Some good photos.

Sarcasm! But some interesting stuff.

 
Top