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Old 05-10-2006, 07:47 PM   #11
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Also, do just like full scale (at least the full scale I fly)... don't go straight from landing flaps to flaps up... first bring them to a take-off setting, accelerate some more (while retracting the gear if applicable), then bring them up.

When I said elevator like climb, I meant climbing without having the nose in the sky... just like an elevator... flat. This is good.
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Old 05-10-2006, 08:00 PM   #12
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Hi Wayne;

Couple comments. It depends on the plane!!! I have set up all my planes with flaperons, something you can't do on the aerofly Deluxe simulator. You have a 9303 JR like myself so you have a 2 position flap switch. I set mine up with a 1.5 second delay so I don't get any sudden surprises.

i have spent the last month setting up all my planes from a Cub to a Spacewalker, Bipe and a Paddy Wagstaff Extra. They are all different.

Heres what I am doing. Starting at 20% position 1 and 40% position 2. With lots of altitude and going direct into the wind deploy position 1 and watch the plane. Some pitch up and some pitch down. After you know which is which, land and add in a little of up or down elevator in the flap set up, as required, until the deployment of the swith has no attitude change with the plane. It should just slow down.

PS The JR flaperon set up instructions are incorrect. Won't work the way they say. Took me a while to figure it out. Easy fix. Call me if you want some help.

Play with it until you like what you get. With flaperons deployed on landing keep more throttle than usual because it will slow down and stall. Keep practising your set up 2 mistakes high. When you are comfortable with what's happening and feel you are in control start making lower and lower flybys. Your plane will tell you what it is doing.

Taking off is similar once you have the mix in. Use a little more horsepower than usual.

Only thing I have figured out for sure is that there is no pat answer.

I expect to be working on stuff all summer with my planes to get them how I really like them. Be cautious on a windy day.....they can fool you real fast.
John Kovats

aka Johnny Versatile

MAAC 65460

Hespeler Model Aviators Inc.
Cambridge Float Flyers

I don't have the answers, but I have a personal relationship with the Guy that does.
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Old 05-10-2006, 08:06 PM   #13
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Typical flap angle for takeoff is only 10 degrees.

On landing you could be using from 10 to 40 degrees of flap depending on what you have dialed in. On landing as you add more flap the nose of the aircraft will pitchup so you will have to add down trim.

If on a go around you knock off all of the flap you had, say 40 degree, the aircraft still has all that down trim dialed in so unchecked will dive. This is a common mistake made by many low time full scale pilots and causes many accidents.

The correct procedure is to use full power and retract flaps only 10 degrees at a time. This way you can compensate for the change in pitch attitude.
Jim Daly
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Old 05-11-2006, 11:09 AM   #14
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I have a 40 size UltrStick with quad flaps. This is a really fun plane to play with. I also have a Unionville Beaver with flaps.

I bought this Beaver off fellow modeler. He had maximum deflection set at around 25-30 degrees. I wanted to make some changes to a few things, one of them being the amount of deflection in the flaps. I had been flying the plane for a couple of years with the setup as purchased then I made my changes. I changed the maximum deflection to around 40-45 degrees. I went and flew the plane first deploying the flaps at altitude. All was well and pretty much the same, not exactly but close to the flight characteristics before the changes. I came in for a landing as usual. I was used to landing this plane from altitude, full flaps, nose down and at idle. That is exactly what I did with the new flap setup and all did not go well. Everything was fine until I started to bring the nose out of the sharp down attitude in preparation for touch down. The plane lost airspeed VERY quickly and stalled shortly there after. I immediately went to full power but as this is a Beaver designed for scale flight and not an Extra designed for 3D, I did not have the power required to yank the plane out of the stall. The plane was rocking from one wingtip stall to the other as I tried to correct with rudder, kinda got into a tail wagging situation at 10' off the ground. The end result was a mild crash, which has been repaired. Take note of the lessons I learned here as this was an easy beginners (inexperienced with large flap deflection) mistake.

Also, with the same plane after I made the repairs I was flying on a day with a lot of wind, a day that I probably shouldn't have been flying this particular plane and again I came in with full flap deflection on landing, this time with some power on as I had gotten the feel for landing with this much flap. I was straight into the wind and a large gust hit the plane head on which was not a big deal but the moment the gust was gone the plane wanted to drop like a rock. I managed to flare right before contact with the ground but it was a hard landing. I found out later, here on RCC, that the full flap deflection when hit by the gust caused the plane to slow considerably, despite having some power on and once the gust was gone the plan no longer had sufficient air speed to continue flying. It was explained to me that landing on windy days should be done at take off flap position or even no flaps at all. The purpose of flaps on landing is to allow the plane to slow down while still maintaining flight, on a windy day if you are landing into the wind, the ground speed of the plane will be quite slow while the airspeed could be quite high depending on the wind, therefore accomplishing the same task as flaps on a calm day. Another valuable lesson.

On both of the planes I mentioned the nose pitched up slightly at the deployment of flaps. More dramatic with the Beaver as the wing is farther above the thrust line than with the UltraStick. On the Beaver I have slowed the servo travel speed as well to the maximum time that the 9303 allows. This gives a nice and smooth transition. I also have mixed in down elevator with flaps to control the pitching tendency. I have done this on both take off and landing modes as I want to control the angle of departure or descent myself and not let the flaps do it for me.
Ted LeBlanc
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Old 05-11-2006, 01:08 PM   #15
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Anything more than about 12 to 15 degrees becomes drag. It retains the same lift but the drag goes up proportionally. My old Yellow Cap 10 B, with a very Aerodynamically clean fuse. and flaps up, would come across the threshhold at about 10 ft. 200 ft. down the field it was only down to 5 ft. so flaps were really necessary on a calm day. A little anectdote. Spitfires with flaps down were at about 80 degrees, no in between. When the had to take Spitfires to Malta on aircraft carriers, they put the flaps down while still on the carrier, put a 2 by 4 under the wing and put the flaps back up. Automatic 10 degrees down flaps. When the got to Gibralter, didn't want to get any closer for obvious reasons. they would tae off, drop the flaps, 2by 4 would drop out, up flaps and carry on the Malta.
Tried for my kamikazi pilots licence. Flunked the test.
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Old 05-12-2006, 12:19 PM   #16
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I found out later, here on RCC, that the full flap deflection when hit by the gust caused the plane to slow considerably, despite having some power on and once the gust was gone the plan no longer had sufficient air speed to continue flying.
This has killed several airliners... not so much from gust because of the scale, but from micro-bursts. A plane landing toward a storm that is micro-bursting will suddenly encounter a very large airspeed increase (similar to your gust) while descending on final. The wind itself doesn't slow the plane (due to large amount of momentum) but the first reaction of the pilot is pull back power to get the airspeed back down... doing just what your draggy plane did for you. Then... suddenly the headwind dissipates and/or the decceleration rate is great and the engines are spooled all the back to idle (NOT GOOD in a big jet... takes time to get power again) and you are low and slow without enough power to accelerate to a good flying airspeed... smash. Not good. Funny how aero can apply to everything from models to Jumbos.
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Old 05-12-2006, 06:59 PM   #17
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Look and Learn


Sorry, I haven't been able to keep up with the thread, we put our house up for sale Monday morning and it sold Wednesday so it has been a little crazy around here.

I've read all the posts and see that deploying flaps will need a lot of trial and error, with a lot of learning on my part.

I think I'm going to contact the people close to my area and perhaps visit their fields to "look and learn" from their experience. Then it will be trial, with hopefully very little error.

This is a great web site, with great people and I thank everyone for their input.


Wayne Miller
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Old 05-12-2006, 08:07 PM   #18
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Didn't mean to scare you... just experiment 2 mistakes high.
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Old 02-14-2007, 07:59 PM   #19
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More Flap Talk

When you lower the flaps two things happen. One the Center of Pressure moves aft, causing a nose down effect. The second is they create a downdraft behind the wing. On the piston engine full size Otter they had to move the stab up to get it out of the downdraft. I worked on both the Beaver and the Otter and they have 70 deg. of flap and 45 deg of aileron droop. CRS
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