I know there is a T-28 modification thread, but I thought I'd start this to get a little more detailed.

My intent for this thread is for those who have installed flaps to be kind enough to share tips, pictures, how-to's, or whatever else they are so inclined to do. I'd also like those people who are wanting to install flaps(like myself) can come and ask questions without clogging up the main t-28 thread.

I hope this is successful, I know many people have install flaps on their T's, and they work great. Personally I'm looking for info on size, servo position, and timing/adjustments.

I'll post this link in the other threads to hopefully draw attention to it. Maybe I'm just making an unnessasary thread, but it's worth a try, right!?

Thanks,

-D

Sounds good! I have flaps on mine and have used both the single servo in the fuselage method and the two servos mounted in the wing way of doing things. The single servo is cleaner and lighter, but somewhat cantakerous to adjust. How did you set up yours?

I haven't done mine yet, I wanted to get as much advise and see as many peoples set-ups as possible. I'm leaning toward the dual servo approach just for ease of setup and adjustment.

Yes, the dual servo way is best for simplicity, but I really hate having exposed linkages under the wing. I used a single servo center wing, with Dubro 1/2A aileron linkage hardware to actuate things. Flaps were installed with Robart Hinge Points, three to a side. The problem seemed to be the geometry of the whole set up. Rather than rotating, the actuating arms described a circle which ended up bending things and making life for the servo difficult, even after I replaced the generic 9 gram with a Hitec HS-81. Ball links all around didn't help much either. I went back to the two servo method which is probably the easiest. That, and Blenderm hinges work and seem to be the most effective way to go, I haven't given up on the internal linkage, though. Some have had great success with a single servo and bellcranks in the wing. I have to flap two more T-28's, so I will be experimenting.

Kinda wondering why put flaps on a T-28, mine are pretty easy landers. I would like to see how the mod turns out and what the results are from a landing standpoint. I would probably go with dual servos if I was going to do it.

Originally Posted by buracho

Kinda wondering why put flaps on a T-28, mine are pretty easy landers. I would like to see how the mod turns out and what the results are from a landing standpoint. I would probably go with dual servos if I was going to do it.

Its just a "fun" mod to do. A little more scale, some have done it because they have limited space for an approach, so it helps there. Plus when you start doing paint, retracts, lights, etc, the plane gets heavier and needs to land faster, so the flaps help there. Or like me, I just like to modify stuff

You can check my account for pictures on how i did mine. A dual servo setup that hinges at the bottom of the flaps.

P.s. flaps do make it harder to controll the plane, and will also point the nose further down. Also do not try to use them in the wind. Flaps in wind makes it a kite and it will easely blow over at landing speed.

It's a fun mod to do. I actualy stopped using the flaps on landing, since there is allways a little gust and the low crash, and prop strike rate went up like a rocket for me after i started using flaps. :P

Interesting. Harder to control in what respect, Coenraad? I have been quite happy with my Trojan with flaps. One thing that I do notice, when fully deployed (scale area and forty-five degrees), flying speed will decay at an alarming rate if you don't stay ahead of the aircraft. A fair degree of down elevator is all that is needed to maintain approach speed and is held all the way to the ground, with or without power. Round out and flare need to happen rather quickly, but the arrivals are usually acceptable or better. Roll outs are short, to say the least. Needless to say, with that much flap, the rate of decent can be borderline alarming, but it is nice to be able make a really steep approach, fast enough to maintain good control, yet without having to worry about building up excess airspeed. That is what having flaps is all about. In my case, that ability comes in really handy when the wind changes (180 degree swings are not uncommon at my field) and final involves avoiding flying over the street and staying clear of the trees. With everything down and dirty, it is much easier to fly a tight, close in, pattern without over shooting the landing zone. I agree, you don't need or want excessive flap when operating with high or cross winds and in gusty conditions.

How are you guys hinging your flaps, from the top or the bottom? What hinges do you prefer?

Yeah, I wouldn't think they would be too difficult to use.

I plan on using blenderm for hinge tape for the flaps. If you use ca hinges, you can cut the flap LE straight with the wing. If you use hinge tape, I believe you will need a bevel on the LE of the flap. Actually, the LE should have a fairly large surface, I might slot them and use ca hinges(actually the dubro pinned hinges, ca hinges never work right for me).

Originally Posted by Fravits

Interesting. Harder to control in what respect, Coenraad? I have been quite happy with my Trojan with flaps. One thing that I do notice, when fully deployed (scale area and forty-five degrees), flying speed will decay at an alarming rate if you don't stay ahead of the aircraft. A fair degree of down elevator is all that is needed to maintain approach speed and is held all the way to the ground, with or without power. Round out and flare need to happen rather quickly, but the arrivals are usually acceptable or better. Roll outs are short, to say the least. Needless to say, with that much flap, the rate of decent can be borderline alarming, but it is nice to be able make a really steep approach, fast enough to maintain good control, yet without having to worry about building up excess airspeed. That is what having flaps is all about. In my case, that ability comes in really handy when the wind changes (180 degree swings are not uncommon at my field) and final involves avoiding flying over the street and staying clear of the trees. With everything down and dirty, it is much easier to fly a tight, close in, pattern without over shooting the landing zone. I agree, you don't need or want excessive flap when operating with high or cross winds and in gusty conditions.

Well, stalls are way more dramatic and they occur faster. It's also very easy to get too slow, due to the braking effect when deploying allot of flaps (say 45deg or more).
When flying with flaps you just need to think more about the speed, the controlls need more input and the nose is down quite a bit so you must be carefull to not strike the prop, or try and go so slow the nose comes up too much and you nearly stall.
The max flap deflection i tried was probably around 75deg, and i used around 60% throttle just to maintain speed :P

It is probably my skill, but i flind landing with flaps a fair deal harder. Mind my T28 is quite a bit heavier in the nose due to the P15 and a deal of glue after i nosed it in one time(in stock form :P the tree jumped in the way). Without flaps it responds quicker and stalls are less predictable, so you get more feedback of when you start to fly a litttle slow. Mine started to woble with the wings when using flaps, and going very slow.
I also blew off track a few times with sidewind and even though i used full rudder and power she was just blown sideways.


@Fravits: I used hinghe tape at the bottom. This allows you to simply make straight cuts. Put on the tape and done.


Here is how i did mine. Some pictures are worth more then words

http://www.rcgroups.com/forums/showt...9#post18776284

^^^^Thanks for sharing!!

btw, your link just goes to the main t-28 thread

Haha, Coenraad. I have that same tree at my flying field, too. Don't feel bad.

Two things that you might do to calm things down with your Trojan is to remedy the nose heavy condition. T-28's like to be a little down at the bow, but too much of a good thing causes problems, like no flair at lower approach speeds. another thing that you might try is limiting your flaps to no more than 45% down travel. 75% produces a stupendous amount of drag, far more than is really useful for our purposes. With my Trojan, 45% of flaps produces about a 15/20 % glide slope, without gaining any speed, yet is fast enough to provide plenty of aileron control. Typically, this is done all the way to the ground with round out happening at grass-top level followed by a smooth but rapid flare. The high angle of attack in the flair produces a lot of drag and prevents ballooning, planting the mains nicely and sparing your nose wheel and prop from undue abuse. Beware of a timid flare, though, which will pop the plane back into the air, stall, and thud. this can be done with or without power, but I tend to land power off. Needless to say, as the wind increases, you can back off to half flaps or none at all, depending on conditions.

You have a pretty nice looking Trojan there. i haven't tried the bottom hinge yet, but I think I might like that better than having the big divot under the wing to enable the flaps to drop fully. Blenderm is basic, but very good. i have been using Robart Hinge Points mounted about a third of the way down from the top of the wing. works far better than using flat hinges which i haven't had much luck with when used on flaps.

Don't doubt your piloting skills. You are probably just fine, but keep in mind that flaps don't necessarily make an aircraft land better automatically. They are useful tools that help the pilot deal with varying conditions, but they require practice in order to use them correctly. Use them in varying degrees on all landings and it will become second nature. I can't begin to count all the touch and goes I have done, but I am getting the hang of it.

Again, try those carrier approaches and short landings. You won't believe how sharp your landing skills will get and it is a lot of fun!

Reid

Srt8madness: It should go to page 1419, post 21278. Pics are there, works for me.

Fravits, i think it is allot due to my skills. I reduced flap movement to around 40% not long after. But still i find landing without flaps easier. At the end of last years flying season i put the flaps back to large deflection and used them for slow fly-by's only. Oh and takeoffs with flaps are awesome. Flaps are a nice adition to play with and it is a really fun experience putting them on. For me it was the first mod i ever did (and have done so far) besides painting.

The CG was spot on. but the flaps lower the nose wich means the prop is more likely to strike. The landing stip is also sloped. So landing downslope with flaps is a no-no, as it will bounce. Upslope the prop just is likely to hit, especialy since i have to fly inn over a 6-7 feet fence and allmost slamdunk her down.
I had allot of nice landings with the flaps as well, but also allot of silly accidents becourse i went too slow, or used them in too much (side) wind.
I just need to train allot more with my flaps.

Good thing there is allways this season. The T28 has a new temporalily white paint job and is ready to fly after covering the wings with newspaper and WPBU to prevent paint ripping. The flaps are tightened so they move around less. Exited to fly her again

I allways use flaps on my Radian Pro. Very fun plane to fly as well.

Newspaper and WBPU? Are you using the newspaper for masking or fastening it on the wing with the WBPU?