I'm about done with an ultra stick 40 except for radio gear. There is a ton of posts on here about people reinforcing just about everything you can imagine on this plane. The most common are landing gear block, firewall, tail wheel, verticle fin, wing hold down blocks, and wing dowels. Some of the things make since such as the wing hold down plates and verticle fin. Wouldn't it be better to pop out a landing gear block that rip out the bottom of the fuse or pop out a firewall rather than tear the nose clean off? The only thing I've done was to put tubing over the dowels and put triangular stock on the sides of the verticle fin in front (it did look pretty flimsy there). Why would a tail wheel be a problem? Don't they lift quickly after the plane gains speed? I had planned on just putting a 46 engine in it which is toward the bottom of the recommended size range so it's not like it's going to be overpowered. Do I need to worry about the firewall or tail wheel modification? I won't be flying it for some time since I only recently soloed my avistar but wanted some input on this.

Zetor I agree with you. Many people over reinforce. However The ultra stick is an ARF if I am remembering properly. there have been a number of threads about poor glue joints and weak structures. i would seriously give creedence to what people here are saying about the model you have. If only 1 or 2 people are griping about a particular problem I would disregard it. However if you see a particular problem repetedly brought up. I would act on it. What you did is fine. I would put some triangular stock behind the firewall and on top of the gear block. The firewalls I hear lots of complaints of poor gluing. Lots of luck.

Mark Shuman

My Ultra Stick went through a couple of owners before the upper wing mount broke loose in flight. The only thing I reinforced prior to it's first flight was the landing gear plate. Looking back, I should probably have added a little triangle stock under the wing hold down plate. Everything else was fine. Then again, there must have been 300 flights on that plane before it packed it in. And I KNOW I flew it hard. I had a 2 stroke 78 in it.

If it's supposed to weigh 5 pounds and it now weighs around 12, you have likely gone just about far enough, I think.

Reinforcing things like gear blocks and firewalls and wing mounts are not done for crashing, they are done to avoid them breaking in flight. If there is no triangle stock on the wing bolt blocks and they are not put on perfect, they have force on them every time you pull up or push down and will eventually let go. Gear blocks that are just kind of glued in will rip out on a rough landing instead of staying in. Firewalls coming out when you are starting the plane are really dangerous. If you put in the triangle stock, it will make that not as much a possibility.

If you crash and it takes a bigger chunk out of the fuse because of it, so be it. Don't plan for better destruction in a crash, plan for it staying together and chances of it coming apart in a light crash will not be as high either. If you under build, you will be fixing more. If you over build, you won't. If you crash, you have to fix either way, so fixing an over built plane may have less to fix than an under built plane.

About gear blocks, it seems a lot of ARFs are designed with the assumption that you'll be flying off of a paved runway, and that you always grease your landings perfectly. But when you fly off of a rough grass field, it's not uncommon for the gear mounts to take more abuse on take-off runs than they ever would on pavement. I've seen several different kits that suffered from this.

On firewalls, first, there is the issue of glue joints not being right from the factory. Better safe than sorry here, and it's not that much weight. Second, on trikes, the nosewheel mounts to the firewall, and all the above about landing gear applies double to the firewall now. Lots and lots of trike trainers loose their firewalls from the kanagroo "landings" the plane encounters. Third, a lot of guys don't bother to balance their props, spinners, etc. So the firewall is subjected to a LOT of vibration, and that eventually works the firewall loose. A bit of extra strength means a longer airframe lifespan. (for comparison, get a look at a well designed electric planes front end compared to a glow plane. Electrics have much much lighter construction in the firewall area just because of the vibration. Fourth, guys have a tendancy to put oversized engines in our planes. When you do that, the #3 becomes even more of an issue.

As for tail surfaces, reinforcement helps keep things attached when the over-sized engine from #3 above winds up. It also helps with hangar rash.

Things like wing holddowns are frequently reinforced because guys frequently put those kinds of planes though higher G's than they were designed for. I cringe when I see guys at the field doing full power loops (as in, full power all the way around) and such like that. Many of these planes just aren't built for that kind of thing.

and lastly, sometimes a design really does have a weak point. Something that always fails if you fly past a certain G loading, but is easy to fix. Sure, something else will give instead, but it might fail quite a bit later, and give you that much more freedom to not worry about it.