Could you build an airplane from a car?

Does a space shuttle count?

Ooh ooh, show of hands, how many people have seen 2 aerocars in the air at the same time and also parked next to each other? Me

If you put a fuel tank in it for tooling around, yes.

Okay. You might be right. Don’t really see why you need electrical instruments though. Save them for the Mark II!

I’d be a little concerned that the control surfaces are basically activated by on/off switches… unless you’re going to contrive actuators that have a response curve to the controller position. Don’t know how easy that is, or if such controllers are already present in a car. The solenoid’s a nice voltage-responsive actuator, and you might be able to fashion a voltage control from the stereo volume. If it’s a nice old stereo where everything’s controlled by potentiometers, that is.

Here’s a possibility. You have a rudder, an elevator, and two ailerons that are coupled - one goes up as the other goes down. I’d assume two brake pumps from a split circuit brake system, and each actuates two brake cylinders.

Use the four suspension springs, or the brake disc springs, as return springs on the four control surfaces. Then one brake pump actuates both ailerons via their individual brake cylinders, set up so they move in opposite directions. The other brake pump handles the elevator, and the brake cable and/or accelerator cable controls the rudder.The return spring system is a complete PITA of course, it means that you have to fight the stick to hold level, but there’s not enough tube or cable to do it otherwise…

Hmm. I wonder if you can get away with one aileron? Simplifies things a lot.

You don’t need any electrics really, or brakes. Flaps, instruments, and brakes would be luxuries in this context. You could even do away with ailerons but it wouldn’t be very manoeuverable.

Well… that’s an interesting question. I think the biggest problem would be getting sufficient wing area and lift to get it off the ground.

BTW - you don’t need aluminum to fly.

You might have a problem if you pick a car that has a lot of composite or plastic parts, as those can not be reformed into other shapes.

It’s actually more like a safety factor of 150%. And there’s no reason a steel airplane can’t fly - Beechcraft built at least one such model and we have one at my local airport. It’s heavy and drinks fuel like fish drinks water but it FLIES just fine.

Oh, please - the only way you’re going to get this off the ground is to make it as stripped-down as possible. First of all - you don’t need an electrical system. I have flown airplanes without one and they fly just fine. You don’t need instruments to fly, either - you’re talking about proof of concept here, not a commercial jet or something you’ll fly through a thunderstorm.

The essential controls you need are to the tail for rudder and elevator control. Forget ailerons - you don’t need them for what you’re doing. There have been many viable ultralight and homebuilt designs that dispensed with ailerons - you increase the wing dihedral to compensate and lend stability. My husband owned and flew such a 2-axis, no aileron airplane at one time. They are manuervable enough for standard flight, just don’t try anything fancy.

You’d want to choose a mostly-aluminium small car with a small 4-cylinder engine - such engines have been successfully used to power small aircraft. After that, you need to build two wings. To make this viable you’ll need to strip off as much weight as possible - that means ditch the windows, windshield, all but one seat, strip the seat down to bare upholstery and ditch the springs. The engine won’t need a radiator, or a cowling - air cooling is standard in small airplanes. Get rid of the muffler and catalytic converter. Use three wheels for the landing gear and dispense with brakes. Better yet, use two wheels and a landing skid on the tail. That’s another reason not to have an electrical system - it adds weight.

Have fun designing and building a prop for this thing.

The result won’t be pretty, but I think it is at least possible to do this.