Folding wings.

[George Wallace]

Has any builder working from plans thought about the possibility of folding wings for transportation on a trailer it sure would save a lot of money for me in hanger fees which in Europe are quite expensive.

[jaredyates]

Many have thought about it, and some have posted about it in years past. The consensus as I remember it is that if you could build a Bearhawk with folding wings, it probably wouldn't have many of the traits that you probably like the Bearhawk for, like good performance, light weight, simplicity, etc. There are other options that are designed from the ground up to meet that mission, and those are probably a better choice if that's a priority. It's sort of like going to a restaurant and ordering a BBQ sandwich without the bun instead of just ordering the BBQ plate.

[George Wallace]

That's a interesting opinion. If you happen to know of a aircraft that can be built from plans that has the same spec as the bearhalk 4 seater I would be interested to know. Im not to sure about the food comparison I think that for all intents and purposes the bearhalk should be the same with the option to fold back the wings. I simply thought about asking the question to see if someone had already made this modification and if so what they did and how was it done. I suppose the other option is has anyone else made a quickly De- riggable set of wings to help with transport and storage.? It's not a priority for me just thinking ahead it would make longtime ownership more simple.

[jaredyates]

What I was wanting to say was that you probably won't find a plane that can be built from plans with the same specs as the 4-place Bearhawk that also has folding wings. You might find one that is heavier, much smaller (thus having less structural demands, such as the Kitfox line), etc. Folding wings would be one of those design considerations that you'd want to include from the very beginning if you were designing a plane, since you'd have to consider keeping certain attaching points located in just the right spots, etc. When Bob located all of those pieces in his design, their location wasn't arbitrary- rather, they were located for optimum performance, strength, and weight reduction. Each designer must decide which capabilities he wants to include, and at what cost to other capabilities. His focus was on factors like performance, strength, and weight reduction, so that's why his design excels in those areas, and that's why it doesn't have folding wings, a nose wheel, a ballistic parachute, etc.
If you made the necessary design changes to give the Bearhawk folding wings, you would have a heavier and more complex structure, which means you wouldn't have a plane with the same specs and performance as the Bearhawk.

[Chris In Milwaukee]

It's an interesting thought. It would be an interesting accomplishment, for sure. The wing's current arrangement is the biggest obstacle. The attach point for the lift strut at the fuselage is oriented vertically, so it won't swing away. That would be the first thing to tend to. Up top, the fuel tank taps are on both the front and back of the fuel tank, with lines running fore and aft of the doors. So in that configuration, you'd have to disconnect fuel lines before folding the wings.

If you reconfigured the upper wing attachments so they allowed for a pivot, you've got a folded aircraft width of about 10.5 feet. In the US, max allowable trailer width on most roads is 8.5 feet, so trailering becomes impractical.

Removable wings would be a better option, but with an all-metal wing, you're looking at over 100 pounds apiece, so definitely not a one-person job. No problem for (semi) permanent transportation to a new location, but not practical for everyday ops.

Just a couple other thoughts :-)

[Battson]

There would need to be wholesale design changes to make this possible...

Strut is in the wrong place. Rear spar and attach-point aren't designed to take all that load. No turtle-deck, instead you've got the baggage area and structural tube in your way. Also the wings are so wide, it would still be wider than most cars with wings folded.
It would be a big job, and as Jared says you would likely add lots of weight, upset the balance (lose carrying capacity), and lose a lot of baggage space. After all that - you might as well have bought a different plane!

I can't think of any home-made aircraft of this size with easily folding wings, like you see on so many LSA. I guess it's harder to achieve as the structural strength requirements go up.

[Rollie]

Just my observation here, but from what I've seen with planes like the Kitfox that have folding wings, it seems that most people give up on that pretty quickly. They only take 10 minutes to fold. Then you load it on a trailer, then you take it home and unless you have a very tall garage door, you take it off the trailer to put the plane inside. So to go fly you must get the plane out of the garage, hook up the trailer, load the plane securely, then un load the plane at the airport, un fold the wings, which only takes 10 minutes (but seriously aren't you going to take a lot longer checking everything after unfolding the wings before you fly it?) Then after flying you do it all in reverse to get the plane home. That, from what I've seen, makes it not worth it to most people to take the plane out for a fun 30 minute flight. They usually realize that now a 30 minute flight takes over 2 hours by the time you get the plane out and get it back home safely. From the few I've seen, the planes usually spend most of the time shoved to the side in a garage and maybe fly 2-3 times a year or they end up getting a hangar after trailering it to the airport 2 or 3 times. Of course there are exceptions but I think a lot of the time when we see a neat feature like folding wings or anything else that can save us thousands of dollars with just a "small inconvenience" we fail to see the reality that accompanies it.

[JimParker256]

Yeah, I agree with Rollie. The hassles would really add up over the longer term, and render it impractical as a normal mode of operation.

The only plane I've seen where the folding wing design makes sense to me is the OneX (Sonex Aircraft's single-seater), where everything stays connected, and only a single lever has to be pulled to fold each wing. The wings fold inward, almost (but not quite) meeting over the cockpit. Looks rather like something you would see on an aircraft carrier... only WAY smaller! I can see the utility of THAT folding wing design for sharing space in a T-hangar with one or more other airplanes to save money.

Their website shows how you could fit two OneX into a hangar with a typical Cessna 172-sized airplane. It also shows that 5 of the OneX airplanes can fit into a single T-hangar with their wings folded.