Foam Wings

[Allen Eshleman]

I have a question about foam core wings.  If they are involved in a crash, are they more likely to break?  Are they more sturdy?  Are they heavier?   I am interested in knowing how they are compared to ones built with ribs etc.  Are they easy to repair?  Thanks in advance.

[Scott Richlen]

If you build them correctly you build them to fly, not to crash.  They pretty much splatter just like a built-up balsa wing.

Here's the good news: if you build them correctly they last a long time and are a lot less susceptible to the hanger rash that can really beat up a built-up balsa wing. 

For example: I built this plane in the last century.  I rebuilt it this year.  Actually, I rebuilt the fuselage and replaced the tail this year.  I didn't touch the wing which is a balsa covered foam-core wing.  Wing is Sig dope, fuselage and tail are base-coat clear-coat.

[frank williams]

Allen
Foam wings for a large stunter are about 4 ox per panel, at best.  A builtup  wing willl be a schosh lighter, if open bay construction is used.  If the built up wing is fully sheeted, the weight will be about the same as the foam wing.  The foam wing and the all sheeted built-up will be much sturdier iin  torsion than the open bay.  Easier to repair?  ... builtup IMHO
Frank

[Curare]

Foam wings in my opinion are a bit more reisilient to day-to-day hangar rash and use/abuse. I've even had foam winged stunters go in straight down and the wing has been fine.

With that said, hitting something with the wing - like a flight box or a height marker will absolutely destroy the wing. I hit a height marker with my last foamy and the outboard third of the wing exploded into a pile of white confetti!

[PJ Rowland]

I think the question is valid, albeit unusual.

"If they are involved in a crash;

are they more likely to break? 
Will depend on impact velocity, under normal flight conditions 5sec laps will suffice to destroy most wings.


Are they more sturdy? 
Again under most flight conditions,  ground impact will destroy it.

Are they heavier? 

True, to increase kinetic energy a heavier wing will be a more spectacular crash.


 I am interested in knowing how they are compared to ones built with ribs etc.  Are they easy to repair?   

Not impossibleto rebuild, but if the purpose of the airframe is to explore impact with ground forces, foam wings can be made faster.

Goodluck with your impact testing. Confetti away!! My advice, use tarmac.

[John Lindberg]

I think foam wings are easier to build, and faster to build. Bob Hunt has excellent foam wing cores, as did Johnny Duncan, but he is no longer in business. 

[phil c]

Take a look at "The Corehouse" down below in the vendors section.  We've got or can cut just about any wing to fit any need.

Foam wings are faster and easier to build.  The simplest wing is a foam panel with top and bottom spars covered with silkspan and then plastic film.  A 48in. stunt trainer built this way will survive a straight in crash into moderate turf without breaking anything.

Larger planes, balsa sheeting, etc take more time and preparation.  In the end they can be very close to the best built up airframes.

The most recent wing I cut was for a Windy Urtnowski Cardinal.  It was cut from somewhat denser foam but hollowed out about 60%.  That saves just about all the weight of the covering and finishing.

Another approach to building a bigger PA plane is the capstrip method.  One of our local flyers, Dave Noll, built a series of capstrip winged planes in the 1980's that were fully competition capable.   This procedure uses top and bottom spars, sheeting on the leading edge at least part way to the spars, and sheets top and bottom on the trailing edge with a rear capstrip.  Balsa blocks for the hinges are buried in the trailing edge. 1/4-3/8 wide capstrips run between the leading edge sheeting and the trailing edge sheeting. The final covering can be done by any covering method desired.
 
It was too bad Dave just couldn't develop the skills to get into the top placings in Open class, or Expert.

Pic is a flapless stunter, 750 squares, 49ounces. 60in. span  with a hollow foam wing.