Greetings,

I'm a newbie to the group and the R/C hobby, and have enjoyed reading the massive amount of advice/debate/hearsay available on RCUniverse. For what it is worth, I need to say "thank you" to basically everyone for sharing the knowledge and experience each one of you has accumulated over the years. It has been a tremendous help thus far.

Now that the sappy stuff is over with, on to my question...

I recently completed a Great Planes PT-40, and to the best of my knowledge I think I have done a satisfactory job with the kit. Definately a learning experience! All control surfaces are lined up straight, with the exception of the right aileron, it appears to have a slight "twist" along the length of the flap. If I center the servos and look at the aileron from the rear, it dips below the wing TE about 1/16" near the fuselage, and is raised above the TE of the wing about 1/16" near the wingtip. Forgive my misuse of R/C jargon, I haven't been around long enough to fully pick up on the lingo.

My concern is that this twist will create drag on that side of the plane, and whether or not I will be able to correct it with trim settings elsewhere. I know a 16th of an inch is not much, but it is just enough to be noticeble when up close to the plane.

Any thoughts on this? I don't know for sure if the wood was warped before I installed it on the plane, but I don't think it was. This is possibly the result of some binding when installing the hinges. Note: the aileron itself moves freely, and has good throw both up and down, and meets the recommended specs provided within the manual with no problem.

I haven't flown the PT-40 yet, but if the weather holds out this weekend then I'm looking to make it happen. Thanks in advance for any advice anyone may have.

Sounds like you have split the difference so go fly!

hmmm there is two ways to go about this.

a:
try to fix the warp either with the aileron still on the plane or off it and risk damaging either the plane or the aileron,

or

b:
fly it like it is. 1/8" total warp on a trainer shouldnt make a real diffrence in flight... at worst you would just need a touch of rudder to trim it out. if this was a high performance speed plane then yeah you would want to fix it, but a trainer is alot more forgiving in minor descrepencies like this.


my advice.. go for it.. you probably wont even notice.

Hi Tex-Deck, go fly,probably most planes in the air are flying good with a lot worse misalignments,now time to start the second plane?

I had the same identical problem with my PT 40,and after a slight
trim I put over 70 flights with no problems.

tex-deck, hello and welcome , my alpha has a slight warp also and it doesn't hurt anythang. and i hope you have an instructor(sounds like you would) to have them trim it out for you...good luck spooner

Heck,
I have the same on one of my trainers on the stab.
It's so bad even non flyers notice it.
It was a RTF trainer and one of the stab hinges was insered to low on the left side.
Plus the elevator has some warp in it.
When I trim for a nice level right side,the left side is down a good 1/8 "
It flies like a dream so go enjoy yourself.
BTW,
Even on dead stick landings it has no affect.

The first plane I put together, a trainer, was far from perfect. It still flew just fine and I soloed on it. It's still around with skies for flying off snow.

I built my first trainer, and the right aileron is slightly lower (1/16"-1/8") with the servo centered.. it flys alright, but always wants to roll very slow, couldnt trim it enough to fly strait and level...

You could twist it back into position and use a heat gun or a covering iron on it to take the twist out of it... you may have to remove the aileron to do this. On the other hand, you could leave it alone... like stated above... it may not make any diffrence.

Welcome to the hobby

I have the same thing on my PT-40. If built per the plans, the wings have quite a bit of twist designed into them (washout). The washout (tip twisted downward) aids in stall resistance. Even if the aileron is perfectly straight, it will not seem to be parallel to the trailing edge of the wing. Just fly it man, the PT-40 is a gentle plane that is very capable of basic aerobatics. Inverted flight can be tough, but is doable.

Good Luck!

Hey gang,

Thanks for the awesome response!

Well it looks like the consensus is to get my plane in the air, so I have moved forward with the project. I've contacted some guys from a local field, and made an appointment with an instructor for Sunday morning. Weather permitting, we'll be flying!

Terrell, I've been thinking about the next plane even before my PT-40 was finished, just didn't feel it was right to start work on something else having not even seen my first lift off yet. I suspect within the next few weeks I'll begin work on another. Hopefully the trainer won't explode on impact and I'll have the luxury of owning two working planes at one time when the next one is completed.

I'll keep y'all updated, thanks again for the support and advice. Wish me luck!

TX-Deck out.

Hi Tx-Deck,the PT 40 is such a great trainer,you'll have a blast Sunday,have fun.

Well gang, everyone's advice held fast, the plane is flightworthy!

I tried to have it checked out on Saturday morning, but by the time I got to the airfield the winds here in Houston had kicked up to around 20-25mph STEADY. Most everyone had left, so I had no choice but to try again the next day.

Sunday morning looked really promising, with clear blue skies, a crisp chill in the air, and virtually no wind at my house. Well, that didn't last long. As soon as I got to the field and out of the car, 20mph winds AGAIN!!

Regardless I met with the instructer and we checked out the plane, most everything passed the test and he decided to take it up for a few minutes. I agreed with him when he told me that it was probly not a good idea to train with the current wind.

We addressed the airleron issue and just as everyone here mentioned, it was basically a non-issue. He reiterated the fact that most trainers have small flaws such as mine, and most of the time can easily be trimmed out on the radio.

Even though I didn't get any stick time, it was still a thrill to see my project take to the air and survive on such a windy day. Now I just have to labor thru the week and get back out there ASAP!!

Thanks again everyone for the advice and feedback.

If you think that was exiting wait till you get the sticks in hand and the plane in the air.Fun isn't it? Let us know when you get to fly,thanks.

Just curious,what engine do you have?
With a 20 mph wind and the dihedral on the PT 40 IT's
a tricky flight.

Running a TT .46, with a 10x6 prop, plenty of power so it seems.

Really the only comments during flight the instructor made were "you notice how bad the wind is today?"

Literally, as soon as he would make a downwind turn it took quite a while for the airframe to turn back into the wind. I guess it didn't actually take a long time, just seemed to carry the plane a long ways. Pleasant surprise to find that it didn't have much trouble coming back to us before making another turn.

TX-Deck - Congratulations on your flight success. I've noticed the PT trainer is kind of sluggish making a turn into the wind as well. Since you are aware of it, then you just have to keep in mind that you have to start making the turn earlier than you would otherwise.

Also, you may want to consider putting an 11-5 prop on your .46. It will give you a better climb and reduce the top speed. Also, it will accelerate a little better. Just my 2 cents worth.

Congrats again. Bet you feel a lot better now that it's flown.

I must add here....

The instructor made this maiden flight look REALLY easy. We are going to hook up again soon and give it another run so we can trim it out under less severe conditions.

TX-DECK,
Congrats on your planes first flight. I was also at the field this weekend and did not even consider taking my LT40 out of the truck in Houston. It sounds as though you will have many fun flights on your plane even in the wind.

Aggie_Grad

P.S. Which field are you flying at?

LOL, we digress.....

Aggie_grad, I was out at Scobee before noon on Sunday.

It really makes me happy when I hear the enthusiasm expressed by you in your previous posts. It reminds me of the butterflies I used to get in anticipation of my next opportunity to fly.

I've been in the hobby now for about a year, and I still get that good feeling before flying.........But we all must admit those first few flights were really something....


CDSMITH...