Well, I have been flying sport aerobatics for about a year, so I decided that on the first clear day out (its was raining here for about two weeks), I would take out my good old faithful trainer (Hobbico Avistar MKII) for its first flight in about a year. Well, I was combating a 15MPH crosswind on the runway doing touch and go's, and on the 9th one, the wind picked up right when I was at full throttle moments from takeoff, and the plane flipped over into the embankment off the side of the runway (first crash in 10 months). I go to retrieve the plane, and there is a hole in the wing and the fuselage directly above where the landing gear is bolted on is cracked (I converted the plane to tail dragger). I take it back to the pits, remove the wing, and assess the damage more closely. I found out that when I converted the plane to tail dragger, I did not epoxy the landing gear block into the bottom of the fuse, so the only part holding the landing gear block to the plane were the bolts that fastened the gear to the plane. Well, most everyone that walked by said that the landing gear shifted just enough to only cause a crack in the bottom of the fuselage. So, now I am wondering if I should go ahead and epoxy in the new landing gear block, or just bolt it down? If anyone wants to see, I may have pictures of the damaged wing still on my camera, as well as the repair I made, but the landing gear I am still working on.

Also, I still have to cut my new landing gear block, but would it be better if the grain of the wood was parallel to the sides of the fuselage or perpendicular? Or does it not matter that much? Thanks in advance.

If it were up to me I'd epoxy them in. Landing gear blocks take quite a beating out there and the extra bit of epoxy's holding power will help you out.

Ken

definitely epoxy it in. If you're not using them already, I'd use nylon gear bolts also. Using metal ones is just asking to get your gear block (and maybe more) torn out on a botched landing. With the nylon bolts your gear will just shear off the bolt heads and not damage the mounting block.

Definitely epoxy. With the nylon bolts, make sure that when you tighten them in, go at least 1/8-1/4 turn past the point where the bolt is feeling tension. This is necessary to preload the bolt. If you don't, they won't shear off properly when they need to.

Brad

Definitely glue the block in.

And go with the nylon bolts. They'll save you in the long run.

And when using nylon bolts, get yourself a tap to match the bolt size. Then thread the wood block. Treat the hole with CA and when thoroughly dry, thread the holes in the wood again. You'll have done a couple of "better" things. You'll save yourself the time and money that T-bolts would have cost you. And you will be building a measurably lighter model.

And some day, when your models are living through the winter and you're getting them ready for the next season of flying..... Swap out the old nylon bolts. Nylon dries out and get a touch brittle. If you don't remember, don't sweat it.

And, oh yeah, please, when you're doing this nylon bolt retrofit........ take a minute to measure the nylon bolts and cut them suckers off so they don't reach so far into the airplane. Excess bolts sticking out look so tacky and well.... so sloppy. They're so easy to trim. Now, about those sloppy looking tiny little elevator/rudder horn bolts that're sticking through.......

I'm gonna let you guys in on a little info a very wise moderator who's name will remain anonymous gave me concerning the nylon landing gear bolts, just a little something to think about. Here it is. If you look at your landings on a scale of 1 to 10 with 10 being the worst in terms of impact, hard landings. While it will require an 8 to 10 type of landing to rip out the landing gear with the regular steel bolts, it may only require like a 6 or 7 type landing to shear off the Nylons bolts. Now where does that landing gear go as the nylon bolts shear off? That's right they tumble underneath your plane & tear the H*&^ out of the bottom of your plane as it goes skidding down the runway. Where as that same 6 or 7 type of landing with steel bolts would have held up & done zero damage to your plane.

The more I thought about what he had said, the more it made perfect sense to me. Both of my Trainers suffered some pretty hard landings in some of my early flights & they are both still in perfect tact.

I know longer buy into the nylon bolts on the landing gear philosiphy. The whole idea behind it is that you won't rip out the landing gear block, but either way if your landing gear comes off you are going to cause some damage to your plane & need to repair it. So the only thing we acomplish by using nylon bolts is putting ourself in a situation where we end up in that have to repair it mode, on landings that might not have been that bad to begin with.

Epoxy the LG block in and don't forget to add some tri stock bracing from the top of the block to the fuselage sides.

As others have stated, the LG block takes a good amount of abuse. Ideally you want to distribute the force along the fuselage also to help dissapate it.

As for the nylon LG bolts - there is pro and con. I know how they are supposed to work, however, with the "unschedualed" landings I have made, I have not had a nylon bolt shear off before the LG block let go. This is just my experience.

unscheduled landings lol, yeah I like that. I don't crash, I just have some unscheduled landings.[sm=idea.gif]

I agree for the most part, but, it's when you do have the category 8-10 landing that the nylon bolts come in to play. Such as a half out of control dead stick crash/landing. However, I play the odds and use metal bolts for the landing gear. I Have ripped the bottom of the plane out once (metal bolts) and broken the gear block but for most of the time it just holds as designed. BTW, when I did have the 10 landing, the wheel pants went through to bottom of both wings. It's one of those "matter of Choice" decisions. Either way you are rolling the dice depending on how well you land.

Install the block with the grain perpendicular to the Fuse sides.