Hi I crashed my spad the other day. (I was flying the kind built using PVC gutter pipe for the fuselage) I cracked the front part of the gutter pipe where the engine mounts, and was wondering if i just cut off the the bad section of pipe and moved my wing back the same distance how the plane would fly. I'm only 15 and don't understand all the physics of flight so any advice on what i should do would be greatly appreciated.

Thanks

As long as there's enough room for the ailerons to work, and not interfere with the horizontal stab, it should work fine. However, moving the wing back the same amount that you cut off, probably won't have the desired effect, it'll make the plane noseheavy, because you have in effect shortened the tail moment.
Cut the bad part off, then reinstall everything except the wing hold down dowels, and rubberband the wing to the fuse, by laying the dowels under the fuse, (so the wing is banded on, but still movable), then slide the wing until it balances on, or just ahead of the spar, then mark the leading and trailing edge of the wing on the fuselage, remove the wing, and drill the wing dowel holes 1/2" ahead of, and 1/2" behind the edges of the wing. Your cg should be just right then.

Yup, what he said. Or make a new nose for the plane with smaller or larger diameter pvc square pipe. I have started making all of my fuz's out of canadian and using 3 inches of american for the nose piece, if it breaks I only have to replace the 3 inch nose piece.

My suggestion might be a little tough, but build a new fuse. Most of the tough parts should be done. All you really need to do is trim up a new fuse!
Again, this may be more work than you are up to, but if you have to cut too much off, moving the wing back to re-balance would reduce the distance between the wing and tail feathers too much, thus reducing your pitch/yaw sensitivity too much. That was all kind of a mouthful, so if you need it explained better, let me know. Good luck.

TY

Here's a pic of a short coupled plane i built some time back


It was 074 sized, with a 24" wingspan. There was a whopping 1/4" between the ailerons and the horizontal stab. It wasn't pitch sensitive at all, the cg needed to be moved a bit forward, though. As long as the tail feathers are adequately sized,and the cg isn't too far back, the plane won't be pitch sensitive. You've got little to lose by trying cutting the fuse off. Try it and see. If it doesn't work, then build a whole new fuse.

Just my 02.

That spad still ranks No. 1 in cuteness! You almost want to pet it!

This depends how bad it cracked. If it cracked bad enough that chuncks are missing...yep...time to to modify or build a new fuselage...but hey, this is Spadland If it just "split"...and you don't mind your plane looking battle worn, there is nothing wrong with a little duct tape or packing tape.

In the summer of 2001 at the NATS I was in a mid-air with a Dogfighter...and the dirtnap split the fuselage at the front wing hold down dowel and front of the fuselage and knocked the firewall loose. Being in combat competition, I had to get it ready for the next round. I cleaned the area real good, spread the cracks open, used medium CA in the crack, and then wrapped clear packing tape around the fuselage several times closing and covering the cracks with the tape. I drilled some new holes next to the old holes and remounted the firewall. The field repair took several minutes, and the plane continued to fight...that day...the next day...the next month...into the next year! I continued to use that plane as is...still flyable! It even flew again at the 2002 NATS! That one repair actually lasted a year and a half until the plane finally met it's end in a rather infamous match with Wes "Sheepy" Parmenter and his Sheepzilla...but that is another story (not worth repeating).

Thanks guys i really appreciate all of your advice, i would be lost without all of your knowledge. Luke