Folding wings

OK, you have to humor me on this.
I'm not talking about anything unrealistic (like Moller's skycar, etc).
But what would prevent a design (even low performance/ultra light to start)
that would allow a pilot to fly into an airport, then fold up his wings and
cruise down surface streets at 45mph?

It doesn't sound that complex. I bet a homebuilder could do it with parts
laying around his garage.
The only serious issue I can think of is having a spinning prop on a city
street.
Even so, couldn't you "disengage" the prop and then couple the engine to the
mains somehow?
I realize that is a bit more complex and would mean some kind of
transmission.
I'm just throwing out ideas here.

It sure would be nice not to rent a car or get a taxi!
It also seems that there would be a MUCH larger interest in GA if people
could potentially commute this way.
For example, I would consider working in Reno and living in Minden if I
could fly into Reno, then commute to my work.

I'm serious about this, but I'm ready for the flames ;-)

Adam
N7966L
Beech Super III

I like it. And it woud cuise at 200 mph.
"mindenpilot" wrote in message
...
OK, you have to humor me on this.
I'm not talking about anything unrealistic (like Moller's skycar, etc).
But what would prevent a design (even low performance/ultra light to
start) that would allow a pilot to fly into an airport, then fold up his
wings and cruise down surface streets at 45mph?

It doesn't sound that complex. I bet a homebuilder could do it with parts
laying around his garage.
The only serious issue I can think of is having a spinning prop on a city
street.
Even so, couldn't you "disengage" the prop and then couple the engine to
the mains somehow?
I realize that is a bit more complex and would mean some kind of
transmission.
I'm just throwing out ideas here.

It sure would be nice not to rent a car or get a taxi!
It also seems that there would be a MUCH larger interest in GA if people
could potentially commute this way.
For example, I would consider working in Reno and living in Minden if I
could fly into Reno, then commute to my work.

I'm serious about this, but I'm ready for the flames ;-)

Adam
N7966L
Beech Super III

mindenpilot wrote:

But what would prevent a design (even low performance/ultra light to start)
that would allow a pilot to fly into an airport, then fold up his wings and
cruise down surface streets at 45mph?

It's been done at least twice. These days, I'd bet the safety equipment required
for highway vehicles in the U.S. would weigh enough to make it absolutely
impossible.

The two approaches I've read about are 1) Have the wings and empennage attach
to the car. The car lands, unhooks the assembly, and leaves it at the airport.
2) Use detachable and folding wings and tailfeathers and trailer them. The EAA
museum at Oshkosh has one of these on display.

These didn't make very good airplanes because of the weight of the automobile
running gear. IIRC, only three of design #2 were built, and I think that was in
the 50s.

George Patterson
He who would distinguish what is true from what is false must have an
adequate understanding of truth and falsehood.

I'm not talking about anything unrealistic (like Moller's skycar, etc).
But what would prevent a design (even low performance/ultra light to start)
that would allow a pilot to fly into an airport, then fold up his wings and
cruise down surface streets at 45mph?

What is the difference between the skycar and what you describe?

Nothing prevents you from designing something like that, but what will
result is an airplane that doesn't fly very well, and a car that
doesn't drive very well. All the stuff you'll need to carry around in
order to be able to safely drive the vehicle on roads after landing
would need to be carried as part of the airplane, making it heavier
and lowering its payload. This includes the extra weight used to make
the vehicle crashworthy (assuming you would like to survive a battle
between you and a Toyota). And all the stuff you need to fly with
would need to be carried while driving on the ground - this means
you'd be dragging the wings and tail all over the place. You would
probably not be carrying fuel in the (detachable) wings, so the fuel
tank would be in the empenage, which has weight and balance consequences.

The tradeoffs would make the engineering much more difficult than you
suspect, and the result would be sub-optimal in all motion regemes.
Put another way, for the same performance, you'd spend lots more
money, and you'd be better off having a cab waiting for you.

Further, every time you wanted to take off, you'd have to reassemble
the airplane - at the very least, you'd have to put the wings back on.
The fasteners would be a weak point, and the time spent doing that
would reduce the time savings of commuting by air this way. Looking
(cynically) into the future, with all the TSA stuff coming down, such
a vehicle would probably be seen as a threat to security, and you
might end up on the receiving end of hours of security questioning
every time you wanted to take off or drive away, especially at a new
airport.

If you are thinking of doing this for commuting, you'd be better off
leaving a car in Reno for your commute, and flying in a regular plane
from Minden. If you are thinking of it for the coolness factor,
what's wrong ith Moller's aircar?

Jose
--
Nothing is more powerful than a commercial interest.
for Email, make the obvious change in the address.

[A flying car] doesn't sound that complex.

Here's a link to the history of flying cars which you might find
informative.
http://www.haynes-aero.com/Netscape/frames.html
Jose
--
Nothing is more powerful than a commercial interest.
for Email, make the obvious change in the address.

All the stuff you'll need to carry around in order to be able to safely
drive the vehicle on roads after landing would need to be carried as part
of the airplane, making it heavier and lowering its payload. This
includes the extra weight used to make the vehicle crashworthy (assuming
you would like to survive a battle between you and a Toyota). And all the
stuff you need to fly with would need to be carried while driving on the
ground - this means you'd be dragging the wings and tail all over the
place. You would probably not be carrying fuel in the (detachable) wings,
so the fuel tank would be in the empenage, which has weight and balance
consequences.


I don't think those electric vehicles made for surface streets (basically
golf carts) have any safety features.
Maybe this aircraft could find a similar loop hole.


The tradeoffs would make the engineering much more difficult than you
suspect, and the result would be sub-optimal in all motion regemes. Put
another way, for the same performance, you'd spend lots more money, and
you'd be better off having a cab waiting for you.

I agree that the result would be less than optimal in both aspects.
I think that would be a minor price to pay.
Start with something simple...single seat, perhaps.
I'd be looking for something that could carry me (175lbs) 100nm @ 70mph,
then scoot me along another 30mi on the ground at 45mph.
I don't think you need much to achieve that kind of performance.

Let's not give up the dream yet!

What is the difference between the skycar and what you describe?

I'm not talking about VTOL.
Just extending what airplanes are already doing.
They fly...
They taxi...
A lot of homebuilts have wings that remove in 5 minutes.

"mindenpilot" wrote

OK, you have to humor me on this.
I'm not talking about anything unrealistic (like Moller's skycar, etc).

***Unfortunately, it is unrealistic.

But what would prevent a design (even low performance/ultra light to
start)
that would allow a pilot to fly into an airport, then fold up his wings
and
cruise down surface streets at 45mph?

***Weight.

It doesn't sound that complex. I bet a homebuilder could do it with parts
laying around his garage.

***If it was not complex, it would have been done by now, by someone much
more brilliant than you and me.

The only serious issue I can think of is having a spinning prop on a city
street.
Even so, couldn't you "disengage" the prop and then couple the engine to
the
mains somehow?
I realize that is a bit more complex and would mean some kind of
transmission.

***Weight AND complexity, and lots of it.

I'm just throwing out ideas here.

It sure would be nice not to rent a car or get a taxi!
It also seems that there would be a MUCH larger interest in GA if people
could potentially commute this way.
For example, I would consider working in Reno and living in Minden if I
could fly into Reno, then commute to my work.

I'm serious about this, but I'm ready for the flames ;-)

Adam

No flames from me, but the problems are great, and the solutions are few.
In a world of building airplanes, you work to save ounces, and all the
things needed for your idea adds tens and fifties of pounds, for each extra
item needed.

A plane is said to be a system of compromises, flying in loose formation.
When you add all the extra stuff needed for an airplane car, it is way *too
* much of a compromise, and likely not be a good airplane, or car.
--
Jim in NC

***If it was not complex, it would have been done by now, by someone much
more brilliant than you and me.

I understand the point you're making, but I'm an optimist.
It doesn't take a genious to be an entrepreneur (thank goodness), otherwise
there would be a lot fewer businesses!
There are all kinds of high-tech approaches out there (as have been pointed
out to me).
While admirable, they may be making the problem (my specific application)
more complicated than it needs to be.


I propose a simple airframe, like a C-152, or heck, even a mini-MAX, whose
wings come off quickly.
For ground transportation, remove the wings, and add a cage around the prop
(like on powered parachutes).
Add some turn signals, brake lights, etc, and that's it.
Nothing more.
What more do you need?
Then you just taxi it.
It doesn't need to go on the freeway, just surface streets.



No flames from me, but the problems are great, and the solutions are few.
In a world of building airplanes, you work to save ounces, and all the
things needed for your idea adds tens and fifties of pounds, for each
extra
item needed.


For the added weight, is the solution as simple as adding power?
In the example I listed above, couldn't you put a 200HP engine (as an
example) onto the smaller airframe to make up for any added weight?



A plane is said to be a system of compromises, flying in loose formation.
When you add all the extra stuff needed for an airplane car, it is way
*too
* much of a compromise, and likely not be a good airplane, or car.
--
Jim in NC


Again, I don't think (at first), the design needs to be particularly good at
either flying or driving.
Proof of concept is all I would be looking for initially.
If it flew reasonably well for short commuter trips, and was able to
negotiate the surface streets, that would be great.

I bet more than one reader of this group (maybe the homebuilt group) could
hack something together in no time.
It would then be reasonably easy to get it certified as experimental.
What about certified to drive on the road?
Keep in mind the golf carts that are road legal...

Adam
N7966L
Beech Super III

"mindenpilot" wrote

For the added weight, is the solution as simple as adding power?
In the example I listed above, couldn't you put a 200HP engine (as an
example) onto the smaller airframe to make up for any added weight?

Now I have to flame.

For you to ask a question, like the one above, shows you have little
understanding of engineering or design. You are clueless. You don't have
a chance of making your proposal working, or even a chance of understanding
enough to discuss it in a rational manner.

Stick to flying, and forget the designing. Bye.
--
Jim in NC