Folding Wings, Aircraft Trailers, and Portable Hangars for Inexpensive Storage

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

Holden

Banned
Joined
Jan 18, 2003
Messages
1,319
Location
USA
In defence of Holden --almost without exception (eg Wernicke's Aircar) EVERY roadable aircraft has folding or otherwise 'shrinking' wings and this constitutes a huge pool of already developed wing 'getting rid of' and 'deploying' when needed technology . There is a sub class of US patents specifically for wing folding (haven't got anything with the number handy but easily googled ) much can be learnt from the prior art both good and bad --excluding one class of aircraft that have needed to fold and stow is not going to help.
Aircar,

Do you have some patents that look good for a moving fold? I looked on Google patents and did not see any that would work. I followed the cited linked patents and still nothing.

My goal is 25 mph folding so that I can land, fold and pull over to a single lane. Just need two lanes to land (24 ft wide). It must be accurately landing on the dotted line with no flare and instant nose wheel loading for total control.

Takeoff is: drive down the road 25 mph and wait for traffic to clear, pull over to the dotted line, put out wings while still moving, and apply full power. Use flaps according to speed limit needs. If 25 mph is limit, then full flaps, and if 35 mph then less flaps and rotate at 35-40 mph. You drive the route to check for power lines and a viable corridor to fly out of. You turn around and return to the area good for takeoff, and then wait for the right traffic moment. You give some lead to get up to speed (25 mph) before you extend wings and meet the "go" point. Allow enough room to accelerate so that cars in front don't become an issue.

Make sense? There are thousands of places to takeoff at any moments in most towns, except major cities. This eliminates the need for 95% of the ATOLs you promote. As I see it, the airplane must be capable independent of what the ground facilities are. To make it work lateral slide is very important so that the airplane does not drift into trees, electrical lines or buildings. It really is about performance. Once you can control position accurately in the air and on the ground, then it will work, once the wing fold is solved.

Any folding system that cannot be done at 25 mph is not going to work. Plane driven's system will not work, nor will the Terrafugia. Once this folding wing is viable, all airplanes will go this way. Only antiques will have trailers and "inexpensive storage" units. Typewriter vs PC. The future is clear.

Holden
 

Dana

Super Moderator
Staff member
Joined
Apr 3, 2007
Messages
9,928
Location
CT, USA
Holden, I see two problems. One, designing a folding system and structure to be rigid in the flight and in the folded positions is a lot easier than one that is rigid enough for wind loads in the intermediate positions as well.

Two, landing on public roads is not legal in most US states.

Dana

If you glue a piece of toast, butter side up, to your cat's back, and drop it from a high place, which way will it land?
 

Holden

Banned
Joined
Jan 18, 2003
Messages
1,319
Location
USA
Holden, I see two problems. One, designing a folding system and structure to be rigid in the flight and in the folded positions is a lot easier than one that is rigid enough for wind loads in the intermediate positions as well.

Two, landing on public roads is not legal in most US states.

Dana

If you glue a piece of toast, butter side up, to your cat's back, and drop it from a high place, which way will it land?
Dana,

I agree.

It was hard to make the first PC and to get internet connection at an affordable cost. Because it is hard does not make it impossible. I am stating the end game and suggesting that this is where efforts should be.

Clearly one can stop, put out the wings, check it over, warm up, and then wait for the traffic to clear. Once cleared, then pull out and accelerate with full power. This would not be as convincing to regulators, in my opinion. They have an excuse to deny. Maybe if I got an oversized load permit....:grin:

If on the other hand one can do 25 mph folding and accurate ground handing (just like a car is required to do), then you can perhaps get the laws changed. That is my hope. The time at width is a factor. If I am wide 10-20 seconds while moving and there is not traffic in the area, then the regulator has less to claim. If I buy car gas, I have paid the road tax...yet I don't use the road 95% of the time. Great deal for them. I show I don't need the FAA nonsense via other technology (no taxes needed to fund burorats), and that I am paying for something I don't get to use. I DEMAND a REFUND for my fuel tax hoping they cave...

Clearly, we have plenty of runways. They are now called roads. To change this, I go around town and find all the right places my airplane can land and submit it to the city. I invite the Mayor and Sheriff to go for a flight and try it out, perhaps me trying it with a permit before doing it with the mayor. If I can show it is safe, then I demand all "safe" landing spots with reasonable traffic restrictions and settle for a few. The toe of the elephant is in under the tent...

Clearly this is ideal, but there are roads in most neighborhoods that would allow a person to get a special use permit to land. Say you need to go to work 50 miles away. You get a permit for your home neighborhood and one for a viable landing place near work. This generates (small) fees :)gig:) which is the point of government, and they look like they are "progressive" and innovative.

I could likely find 10 places in every town where one could land if the traffic is low. Clearly one would not start in LA or New York. Small towns first, and in the outskirts first.

This really requires a very high performing airplane and speed is NOT the most important factor, just like speed is not the factor in a PC or phone...connectivity is.

Holden
 
Last edited:

Rienk

Well-Known Member
Joined
Oct 11, 2008
Messages
1,366
Location
Santa Maria, CA (SMX)
I hope I'm not coming across the wrong way, but IMHO, discussions about wing systems for roadable aircraft belong in that thread.
The purpose of this thread is regarding standard light aircraft, and what flying car proponents might call an intermediary step toward the evolution of their ideal/future system.

I am putting in my vote for keeping this thread specific to folding wings and "portable hangars" for single mode aircraft.
Please?
 

autoreply

Well-Known Member
Joined
Jul 7, 2009
Messages
10,765
Location
Rotterdam, Netherlands
@ Holden

Let's keep the thread about folding not roadables (unless of course, it's related to the specific technicalities of folding ;-)

The Grumman wing system does all what you seem to want. With weak link I meant a literal weak link in the pushrod that commands the wing folding.

Automatic controls is hard to figure out, but certainly possible with this configuration if you're not afraid of a bit of trigonometry. Weight penalty is modest, though it's a very complex system to design and build (lots of parts)
 

Hot Wings

Grumpy Cynic
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
7,850
Location
Rocky Mountains
I am putting in my vote for keeping this thread specific to folding wings and "portable hangars" for single mode aircraft.
Please?
I too would like to keep this limited to folding wings that intend to be folded while stationary, either manually or automatically. But one last comment on the fold while moving
:
Holden:
Have you considered using the wings aerodynamic controls, assuming that the wings are already aligned with the airflow, to "fly' the wings from folded to unfolded position using a kind of FBW? It is then a simple matter to lock in place with servo actuated pins. Use the same for retract but add a "capture and close" mechanism like old Eldorado trunk catches.
 

Holden

Banned
Joined
Jan 18, 2003
Messages
1,319
Location
USA
I too would like to keep this limited to folding wings that intend to be folded while stationary, either manually or automatically. But one last comment on the fold while moving
:
Holden:
Have you considered using the wings aerodynamic controls, assuming that the wings are already aligned with the airflow, to "fly' the wings from folded to unfolded position using a kind of FBW? It is then a simple matter to lock in place with servo actuated pins. Use the same for retract but add a "capture and close" mechanism like old Eldorado trunk catches.
Hot wings,

The answer to your question is at roadable airplane design... #1318 http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/11987-roadable-aircraft-design-88.html#post180306

Holden
 

Aviator168

Well-Known Member
Joined
Sep 21, 2012
Messages
2,275
Location
Brookville, NY. USA
Automatic controls is hard to figure out, but certainly possible with this configuration if you're not afraid of a bit of trigonometry. Weight penalty is modest, though it's a very complex system to design and build (lots of parts)
Automatic controls are actually not difficult. If we can make electric actuators reliable, that would be the ticket. As for folding wing; here is thought. No one ever make a wing that can fold the same way like bird wings do.
 

cheapracer

Well-Known Member
Log Member
Joined
Sep 8, 2013
Messages
6,336
Location
Australian
Just been told that the Mk2 is being constructed. Apparently a much refined model.
The Australian approach.

Hell, does he even have time to fly? To some people that may be acceptable but not the general populace.


[video=youtube;jgfImo7q-0o]http://www.youtube.com/watch?v=jgfImo7q-0o[/video]
 
Last edited by a moderator:

Vigilant1

Well-Known Member
Lifetime Supporter
Joined
Jan 24, 2011
Messages
6,498
Location
US
Hell, does he even have time to fly? To some people that may be acceptable but not the general populace.
I very much admire the work that went into it, but I don't know if I'd want to spend 2 years building an airplane and 5 years building the trailer to carry it.
 

Norman

Well-Known Member
HBA Supporter
Joined
Nov 28, 2003
Messages
3,121
Location
Grand Junction, Colorado
This is the folding mechanism on a Mitchell U-2. It it looks very flimsy compared to the RF5 shown in post #55 but this plane's gross weight is only around 650 lb. The elevon linkage stays connected during folding and automagically rotates the control surfaces 90 degrees up which shortens the chord a bit and puts them into a more streamlined position for hauling. The wing in the picture is not fully folded so the stabilators have not gone all the way into their stowed position. This little plane has a 34 foot span and folds into an approximately 8'x18'x3' package.
 

Attachments

cluttonfred

Well-Known Member
HBA Supporter
Joined
Feb 13, 2010
Messages
8,451
Location
World traveler
One way to solve the control linkage issue with folding wings is...to not have any control surfaces! This is an old promotional video from Avions Mignet, skip ahead to 04:20 or so to see the process of going from trailer (towed on it's own wheels) to flight.

[video=youtube_share;FkXo0R-y7dE]http://youtu.be/FkXo0R-y7dE?t=4m20s[/video]
 

autoreply

Well-Known Member
Joined
Jul 7, 2009
Messages
10,765
Location
Rotterdam, Netherlands
This is the folding mechanism on a Mitchell U-2. It it looks very flimsy compared to the RF5 shown in post #55 but this plane's gross weight is only around 650 lb. The elevon linkage stays connected during folding and automagically rotates the control surfaces 90 degrees up which shortens the chord a bit and puts them into a more streamlined position for hauling. The wing in the picture is not fully folded so the stabilators have not gone all the way into their stowed position. This little plane has a 34 foot span and folds into an approximately 8'x18'x3' package.
Same fatal flaw as in the RF5 (the crash report is on the beginning of this thread). You can lock it with 5 degrees of extra dihedral, but you'll die when the wings start coming up. A simple half-round band with only two holes can avoid that.
Even the RF5 is prone to damage from the folding wing (rear/fwd). This one is going to be bent the first year. Let's hope the pilot notices that before the next flight...
 

Norman

Well-Known Member
HBA Supporter
Joined
Nov 28, 2003
Messages
3,121
Location
Grand Junction, Colorado
Same fatal flaw as in the RF5 (the crash report is on the beginning of this thread). You can lock it with 5 degrees of extra dihedral, but you'll die when the wings start coming up. A simple half-round band with only two holes can avoid that.
Even the RF5 is prone to damage from the folding wing (rear/fwd). This one is going to be bent the first year. Let's hope the pilot notices that before the next flight...
I know a guy who has 800 hours in a U-2. Over the years I've heard him kvetch about other features of the plane that need constant repair but not the fold mechanism. I'll ask him about that. This may not have been as much of a problem for the U-2 as it was for the RF5 because the U-2s outer panels are only 7.5 feet long. Could you describe the "simple half-round band". A picture or drawing would be great.
 

Hot Wings

Grumpy Cynic
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
7,850
Location
Rocky Mountains
but you'll die when the wings start coming up.
Actually......In this case maybe not fatal. This has happened with this particular model and the plane flutters to the ground like a Maple tree seed. The cases I know about resulted in no injury.

But the system could be improved upon to take the human factor out of the equation, which is unfortunately becoming more imperative as the number of people with poor problem solving skills increases. My wife was just relaying a series of humorous examples from some Facebook posts - including the classic distraught motorist with dead batteries in the door remote that didn't know how to use the attached metal key.

In contrast the Antelope on the local college campus have learned how to use, well watch , the cross walk lights when the traffic is heavy. Makes one wonder..........
 

autoreply

Well-Known Member
Joined
Jul 7, 2009
Messages
10,765
Location
Rotterdam, Netherlands
I know a guy who has 800 hours in a U-2. Over the years I've heard him kvetch about other features of the plane that need constant repair but not the fold mechanism. I'll ask him about that. This may not have been as much of a problem for the U-2 as it was for the RF5 because the U-2s outer panels are only 7.5 feet long. Could you describe the "simple half-round band". A picture or drawing would be great.
Imagine a small, curved plate that's mounted to the outer wing. When you fold it out it's shaped such that it'll continuously block the locking mechanism until the actual connection is in front of the locking mechanism.
Actually......In this case maybe not fatal. This has happened with this particular model and the plane flutters to the ground like a Maple tree seed. The cases I know about resulted in no injury.
One can get lucky, I know of a pilot who survived it in an RF5. But the risk of ending upside down are huge, which for example was fatal for the two guys in the RF5B accident I posted before.

It's really not that hard to make these kind of mechanisms (almost) fool-proof.
 
Top