I am graduating to my first low wing after 6 months on a trainer. I have built a cherokee (great planes) 60" ARF. I have read that the flaps help the transition to a low wing on landings. I assume it slows the plane down some. could someone help with the proper use of the flaps. there are two stages of deployment. I have done all the reading the plane has to offer but would like some experianced advice before my first flight. any and all help is greatly appreciated!! thanks

I've got the same plane (reviewed it for RCU) and it really doesn't need the flaps. But they can be fun too!!!!! The best thing to use them for is making slower approaches on your landings. The best advice I can give you is to simply get up about 2 mistakes high and start making landing approaches and practice deploying the flaps so you get the feel for how the plane is going to respond. Once you start pulling the throttle back and the plane starts slowing is when you deploy them. If the plane is moving too fast when you use the flaps it will balloon up and climb. But keep the plane up high while you practice and you'll get the hang of using them. Once your are comfortable with how the plane responds with the flaps down then you can start trying them on a landing.

Hope this helps

Ken</p>

So I understand.... flaps don't slow the plane down per say but give the wing additional lift allowing you to fly slower than w/out flaps.Is that right?

That is correct. When you extent the flaps it increases the surface area of the wing which causes the wing to produce more lift at a given speed.

Ken

They do slow the plane down some too though with the increased drag they create. If you get used to landing without them and then add them in you'll find yourself way short on approach speed.

thanks guys.
Ken you said you have one and did the review. Very nice review, hope you get residuals; prob. the biggest reason i purchased it. It dose have a bigger tank than im used to. I am mounting a .46ax. Around how long dose that tank last. the tank is 420cc with a .46ax. the only experiance i have is with a 275cc with a .46LA.. im sure i will find out but was just wondering. thanks again and im sure ill have more questions later.. Im building it using your review. working on the cowl now...

Just remember that with flaps or without flaps..altitude on approach is controlled by the throttle and speed is controlled by the elevator......with that said get a good flyer to stand on the spot with you....shoot several approaches without flaps...if you like the way the plane handles without flaps fly it that way.....add the flaps later when you are used to the aiplane.
Just because you have flaps doesn't mean you have to use them.....I bearly use flaps on my P-47, and make real nice landings...
Good Luck

Hi!
Flaps should not be considered at all when landing or starting!
It's just a gizmo thing to play with when you really are good att flying... not for a newbie!

No, flaps are a tool to make slower landings and takeoffs if you want to. On that particular plane they are a luxury from a sport flying standpoint, but if a pilot wants to fly it scalelike and do takeoffs and landings like the real plane then the flaps are necessary for that.

I had that same plane, I never used the flaps, it flies almost like a trainer it is a little faster but I think that's the only difference, you better use those two servos in somenthing else cause I really doubt you'll use the flaps. and for the fuel tank, I had an Evolution .46 engine on it and I used to make like 20 minutes flights with no problem.

IMHO the advantage of using flaps on the on an aircraft such as the GP Cherokee is not the lowering of the landing speed but the increased drag, which allows a steeper landing approach without speed buildup.

Hi!
Flaps changes the way the plane behaves and "sits " in the air and it is my 35 year experience that landings nor taking off is not easier using flaps on most airplanes.

jaka, I must disagree with you and I do have 3 more years expierence than you. Dropping the flaps increases the wing's camber thereby increasing lift and drag and decreasing speed without increasing the likehood of a tip stall. I have the same Cherokee and I like to use flaps if there is little or no head wind. It makes the plane even easier to land more smoothly than it normally is. I find with the Cherokee I need about 8% down elevator mixed in with with the flaps for a perfect landing configuration. I have three other planes (Pawnee, Trojan T-28, and an RV-4) that also have flaps and provide similar results. I also see no reason a beginner should not use flaps if it makes him feel more confortable with a given plane.

Bruce

I again disagree with a beginner using flaps.....flaps function is to increase lift at lower airspeeds.....because flaps change the wing you also get an increase in drag....
Ok we all agree...with added drag you run the risk of a stall, because flaps increse lift at lower airspeed you might not recoginze the stall until it's too late......
Throttle management is paramount....as this is a beginners forum I have assumed (you what happens) that cgibbo might not have the experence....
That's why I say at first to have 1 a good flyer stand with you on the spot and 2 shoot approaches with no flaps and see hoe the airplane is......You can do flaps after you've gotten used to the airplane

To think that flaps increases lift and drag by increasing the wings camber is ignoring what is really causing the increase in lift and drag. When flaps are deployed the angle of attack goes up on that section of wing (usually the inward section) because lowering the trailing edge of the wing lowers the reference point where the cord line is measured. Because this section of wing has a higher angle of attack than the outward section it is the first to stall leaving the outward section still flying. And because this outward section has ailerons control is maintained. Just like you said it reduces tip stall. When you decide to land you don’t need extra lift but the ability to fly slow and still maintain control will come in handy.

I used the flaps(first time I've ever used them) on the maiden (of the GP Cherokee) because I have a short runway. I did a take off attempt without the flaps and found that the flaps were necessary for take off and landing For landing fly a few approaches without the flaps and see if they are needed.( For a 2 position switch) drop the the flaps on about half way down the downwind leg and use for landing.( For a 3 position switch) About half way down the downwind leg drop the first set of flaps and then when on just on final, drop the last of the flaps. Have an experience pilot beside ya and just relax. For landing fly a few approaches without the flaps and see if they are needed. I love using them, they make the landing look very cool. One more thing, take a video and pictures and post them.

If a beginner were learning a full scale plane would they ignore the flaps?
Flaps are a part of flying, if you have them then use them if you want.
Good Luck,
KW_Counter

cgibbo,

I would follow the manual directions very carefully and would practice all situations as described by Ken in post #2.

1) "Full flaps make the Cherokee .40 ARF very steady in the landing pattern, but just carry a little extra power to make up for the extra drag. The extra drag of the flaps also allows you to make shorter, steeper approaches.

2) The Cherokee .40 ARF needs to touch down with a nose high attitude to avoid whacking the nose gear and skipping back into the air. For this reason, landings with flaps require a deliberate flare with high rate elevator to raise the nose.

3) Touch and go’s and go-around’s can be accomplished with full flaps. Just use the elevator to establish a shallow climb.

4) It is preferred to have the flaps up or at “half� setting for takeoffs and climb-outs because the plane will accelerate and climb much better."

The reasons behind the above bold text:

1) You are used to the rate of deceleration of your trainer when the power is reduced. The schematic shows that the section of the wings that is covered by the flaps will increase the lift force that is a produced for certain velocity and AOA (higher coefficient of lift or CL). Drag will increase as well, because drag is always associated to lift. For the second stage of the flaps (full deflection), the drag increases more than the lift, because the area facing the airstream increases much, and the flap acts more like an air break. The only force that opposes drag is thrust; hence, keep that engine pulling the plane, and avoid too low airspeed over the wing.

2) Flaps deflection may introduce a nose down (more frequently) or nose up pitch. The elevator is the only thing that can counteract that pitch and keep the plane in a horizontal or slightly nose up attitude (for landing). The elevator must have enough authority to do that compensation job. Flaps-elevator mix may be good to have. If no mix, then steady elevator input with deployed flaps may necessary.

3) When flaps are retracted, the wing loses the extra lift that had been gained after they were deployed. That may become dangerous if the airspeed is not increased accordingly and progressively and if the plane is too low.

4) Half setting = More lift than drag (Just what we want for any accelerating take-off).

Also, check this article out:

http://www.modelairplanenews.com/Med...ager/flaps.pdf

Best luck and good landings!!

Good, powerful flaps ... the most fun you can have with your clothes on!

Hi!
Why I think a newbie should stay away from flaps (and all other gizmo things) is because he (or she) should have all his focus on flying/landing the plane, and not be bothered with how much flap angle is needed (how should he know) when landing.To much angle and the plane requires more power to retain flying speed. Controlling throttle power is mandatory when using flaps. So is knowing your plane fully! It's just too many factors to bother with for a new comer.
But afer some years practicing. Go ahead!

Would a full scale student ignore flaps????? A full scale doesn't have near the thrust to weight ratio we have....

Hi!
A full scale plane is much more stable than our models...A newbie would be lost if he/she would have to controll throttle AND flaps!

Elevator and aileron is enough for a human brain at that stage!

Following that logic, a newbie shouldn't do anything new with a plane.

There is a kernel of truth there though. If you are used to shooting landings with a trainer and have developed a feel for how the plane slows down and changes in its control response, using flaps means learning it again. The changes are more abrupt and the glide drops its nose much quicker. But to apply that knowledge by saying that beginners should just stay away from flaps doesn't make sense. If you can shoot good landing approaches and set a trainer down gently on the mains, then there's no reason not to set up the flaps and use them. Do you first few approaches 20 feet high or so to get a feel for the new stall speed and glide characteristics, and then enjoy the slower landings.