Just kidding.
I have a .46 p-51 that's a little hot on the landing. I want to try using flaperons to slow the speed during landing. Anyone got any tips for these?
Here's the plane: http://www.nitroplanes.com/p51dmustang401.html
It's got a 57.5 inch WS.
I have the flaperons set to go to 40% down when I have the 'landing' mode set. I'm going to have the elevator stay where it is and adjust it accordingly after I get her up 2-3 mistakes high and switch to landing mode.
I made sure the flaperons move the same amount when the switch is flicked. Made sure the servos could still move to the full extent without binding. Anything else to check for?
How effective are flaperons on small models?
I'm going to try flaperons again tomorrow. Last time I tried it on this plane the model became wild looking. I think 1 flaperon went down while the other stayed put....
G

IMHO flaperons are really a waste of time. They actually make the plane more difficult to handle in some planes. When trying to use flaperons you are trying to get one control surface to do two seperate functions at the same time, flaps and ailerons, and unfortunately it winds up that neither function works well in this situation. I'd recommend forgetting about them. It's been my experience that people who say they are coming in hot and need the flaps to slow down usually just need to work on their landing approach to be able to slow the plane down on the approach.

Ken

I've tried many different type of approaches ranging from slowing the plane down and then bringing it in while maintaining that slow speed to bringing it and and slowing it down on final. I seem to have the best results when I slow to a little above stall speed while preparing for final and then slow to near stall speed. The whole time on final I have to keep a minimum of 10 feet AGL to stay out of plant obstacles up 5 feet from the the edge of the runway. Someday I'll have to go wack some weeds down...
I can easily land on the 1st half of the runway with even the smallest breeze. Calm days require the whole runway and find me screaming at it to stop before it hits some weeds.
Is that the best that I can expect from these types of models.

40 flaps on a hot approach and you're going to balloon up so high that you're apt to stall. the purpose of flaps is to increase lift at lower airspeeds. not act as an airbrake. Yes it is more drag, however it is alot more lift.
I'm afraid your going to find that flaps will make your aircraft hard to handle in the pitch axis.
Sounds like your too high on approach, the trade off for altitude is airspeed. perhaps a shallower approach, with some power on then cut power and flair at runway threshold.
Good Luck

It is if you continue to look for a crutch like flaperons. Please forgive me as I am not trying to be mean but the fact of the matter is this airplane is not a trainer and never will be one no matter what crutchs are applied (same goes for the PTS mustang) .

Using flaperons or for that matter even dedicated flaps in the learning evironment or a first warbird will result in disaster at some point virtually every time. Actually the real reduction in stall speed is perhaps one knot at best and what most people do is find theirselves flondering around around aimlessly too slow and behind the power curve. When they do stall (agine almost every time) its far worse.


I know that particular CMP airplane well and have both assembled a number of them and test flown many more for budding warbird pylon racers.


What you need to do is one or both of two things. First and most important 'do not set up flaperon' but instead adjust both ailerons clevis' so that with all aileron trims at neutral, both ailerons are reflexed up (up from in trail position) around a sixteenth to eighth inch. Now your approachs will be controllable with out diving at the runway which you are no doubt doing now.

Another helpful procedure is assuming your engine idles correctly is to use a larger diameter but flatter pitch prop.

John

I've found on any plane I had that was always landing "hot" that I had the CG to far forward.

I've put flaps on 2 planes I've had..

One was a Telemaster.. with the flaps out it wouldn't land. Just float forever.

The other is my cloud dancer with flaperons..
I tried them once and they made the plane a hand full to fly.

Just kidding.
I have a .46 p-51 that's a little hot on the landing. I want to try using flaperons to slow the speed during landing. Anyone got any tips for these?
Here's the plane: http://www.nitroplanes.com/p51dmustang401.html
It's got a 57.5 inch WS.
I have the flaperons set to go to 40% down when I have the 'landing' mode set. I'm going to have the elevator stay where it is and adjust it accordingly after I get her up 2-3 mistakes high and switch to landing mode.
I made sure the flaperons move the same amount when the switch is flicked. Made sure the servos could still move to the full extent without binding. Anything else to check for?
How effective are flaperons on small models?
I'm going to try flaperons again tomorrow. Last time I tried it on this plane the model became wild looking. I think 1 flaperon went down while the other stayed put....
G
[/quote]

I Have used flaperons often for the same reason you wish to achieve, slow it down for landings. definitly it will require some down elev mix. I also suggest some aileron rudder mix as well. I set this up to be controlled by a switch but also by throttle position (you selec}. Then if you wish to abort landing just increase throttle, flaperons come back to normal and all is well. reason for rudder mix is ailerons become less effwctive at slow speeds. I can't tell how much down elev or rudder mix to use that you will have to experiment with.

What kind of prop do you have on the front end? A friend had a sporster that had the same problem and we changed the prop to a gruber that has more frontal area. Just that drastrically reduced the approach speed to create a really nice landing plane.

Some replies in this forum are a bit *pause to think* off.
Thanks for the tipe Tedmo!
She was my first warbird. Got her beginning of last year. She isn't my last.
JB: The best way to reduce the landing speed (and most importantly the rollout) is provide basically 'negative' flaps that will change the airflow around the wing so that there's less lift? Seems counterproductive to me. I don't dive at the runway. U just got to angle it so that when/where you come out of the turn on final and the point you touch, you'll fly over the bush midway. You'll come close to the bush though.
I think my engine idles right. It won't move the plane forward at idle on an almost concrete surface. A little higher idle then what's required to keep running. I think I'll try reducing the idle.
Once I got the throttle stuck and she flew for 25 minutes. The deadstick was still pretty fast. Much easier then deadsticking my trainer.
I have a, umm, grey 10x8 prop. I was thinking of trying a 10x9 to get more speed. Grubber? What's a grubber?
I was looking for some setup tips, preflight tips on that subject. Most here say not to use them. I understand well the use of flaps. I've never used them on a model.
I think I'll reduce the trottle a little and the flaperons to half what they are and see how she handles.
I've only used flaperons a few times. The first time I hardly noticed a change in flight characteristics. The second time I think was messed up cuz of a setup error. Hopefully I get it right this time.
Cheers all!
G

May sound counter productive but its the most effective method to improve final approach speed and sink rate control on that particular ARF and many like it.

Enjoy

the problem you hsve adding flaperons on the plane in question os that they are out at the tips and when you lower them you are basically adding washin at the tips.while they will generate more lift it is only at the outboard end of the wing and if you do stall there will be no way to recover.you have been given good advice from those thar know but accept the advice from someone still experminting with them because it is whjat you want to hear.check the warbird or arf forum for flight problems and tips.

The idea is to get the sink rate up? I think I understand. Thanx.
This model has ailerons that extend the length. Or is that width?
Never try any thing new when landing.
G

ger87410 I've been around aircraft a long time what are negative flaps? do you mean spoilers or perhaps speed brakes.
you have got to be careful deploying wing mounted speed brakes. not only do they increase drag. but they kill lift right now.

'Negative' flaps would be spoilers. I'm not very good remembering all these terms.
I'm extremely hesitant to apply spoilers on landing. Every piece of me screams that you do not ever want to decrease the lift from your wings during landing. Luckily my radio has a knob that will let me apply either flaps or spoilers depending on which way I turn it. I'll experiment with both ways this morning and see how she handles at slow speed and high altitude.
My understanding with the full size airframes is that you apply spoilers after touchdown so that more weight is transfered from the wings to the wheels to make braking easier and is totally undesirable on an approach because it reduces lift without affecting drag.
Too bad she doesn't come equipped with decelerons or some other airbrake. Maybe I need to rig a little parachute like the space shuttle.
G

or maybe try practicing slow flight at just above stall speed.elevator controls airspeed and throtle controls altitude.these principles apply more so on landing approaches.lift the nose to slow down and add a feww rpm to slow or stop the sink rate.

Warbirds in general land fast and stall at a higher airspeed. Lowering flaperons is the same as washin; a bad situation at low speed.

I agree with alot of the responses that flaperons on a P-51 are bad. Did just that, set up a P-51 with flaperons, came in to land with them down and the plane did in fact slow. So slow that the wing stalled at 25 feet above the ground and tip to the left and nosed in. I had straight flaperons on the flap dial (no mixing), seen that it looked like the plane was going to stall (sight and very mushy controls), added power and then it just tipped wing and fell. Ihave the plane ready for new covering now and when i get it into the air again i think i will just land it hot and NOT touch that dial.

I have to admit that I chickened out. I know I'm a *kittykat* but I was too afraid to screw with the flaperons or the spoilerons. A gentleman at the field who's been flying for ump-teen years recommended no ailerons or anything that could increase the washout on those types of airplanes. (p-40, p-47, etc)
I did find something that worked though.
I reduced my idle and changed my approach.
Now when I pull out of that last leg on final I'm a bit lower AGL, but closer to scraping weeds. I also reduced the throttle by 2-5%.
I think what helped the most was reducing the throttle. I'm afraid of a flame out during final, so I kept the idle just low enough so the plane won't roll on concrete. I think you wanna keep the idle at 2-5% above idle... Not sure on that though.

you want to have you throttle set to whatever it needs to be to maintain a safe sink rate.control your air speed with the elevator.as you bring the nose up with an engine at idle you will at first climb a little till the airspeed bleeds off then you will begin to sink,also as the nose raises you have also increased the angle of attack of the wing which will in itself add lift.what you have to do is ballance the engine rpm to the amount of elevater you are holding to maintain either a safe sink rate[glide slope] or maintain altitude till you reach the threshold of the runway.all without stalling.practice at altitude first but you will learn that you can make your final at just above stall speed,one word of advice,if a wing tip drops it is a sign of a stall,immediately correct with rudder and increase your throtle,do not try to level the wings with airlerons until your airspeed increases as this could cause a nasty snap.while your airplane looks like a warbird it is really a sport type plane and alot easier to fly than a true warbird that has a wing loading over 30 oz/sq ft

Something else to try would be a lower pitch prop.

And something that was mention, but glossed over, is to add a little tail weight. If the plane is even slightly nose heavy it will land faster.

If you can safely add a few ounces to the tail, you'll find that it will slow down considerably on landing.

Minn: I saw that about the CG, but didn't think anything of it cuz I didn't/don't think CG effects aerodynamics. I don't want to put a lower pitch prop cuz that would sacrifice speed. I want this bird as fast as she'll go.
Aerowoof: Here's my calculations, please let me know if I'm wrong.
Here's the stats:
Wing Span: 57.5 in / 1460 mm
Wing Area: 601 sq in / 38.8 sq dm
Flying Weight: 6.0 lbs / 2750 g

To figure out the sq/ft of the wing, I divide 601 by 244 and get 2.463114754.
Then I take the weight (6.0 lb) and divide it by the sq/ft and get 2.4359401.
That's 2.4359401 lbs per sq/ft.
I then convert 2.4359401 lb to ounces and get 38.4.

Aerowoof, according to my calculations I do have a 'true warbird'.
I even added a wireless cam to it. So my wing load is even higher, I think. It also made the plane very slightly tail heavy.
I'll weight it and post on this thread what she weights.

the only problem in your calculation is a sq ft is 12 x 12 = 144 NOT 244

Believe me, CG has a LOT to do with landing speed. Empty your tank and re-check the CG.

If it's nose heavy, shift the battery, or add tail weight until it is correct.

You'll be amazed at how much it can affect landing speed.

I have no idea where I came up with 244. That's what happens when you do this stuff at work and pay only half attention. [:-]
I thought I might be wrong which is why I asked.
Recalculating with 144 instead of 244 results in 29.22 oz/sq ft
That's bloody close enough to 30.
All of this is estimates until I get the thing weighed.
Thanks person with the long name!
G

PS: I always balance with the tank empty.

dont know where you came up with 29 i come up with 23 oz/sq ft.6 lbs =96 oz,600 sq in =4.17
96/4.17=23 oz/sq ft.so like I stated before that puts it in sport aircraft wing loading.for a 390 oz/sq ft wing loading your plane would have to weigh 7 .75 pounds.that would even make take offs very tricky.