<p class="MsoNormal" style="margin: 0cm 0cm 0pt"><span lang="EN-US" style="font-size: 9pt; font-family: Arial; mso-ansi-language: EN-US">Hi all, I have the GPCherokee ARF that comes with flaps, and even when Iset the plane with functional flaps since the beginning, Ihave never used them for only one reason... IDON'T KNOWHOWTODOIT!!!!
Iknow that flaps suppose to make landings slower, but when should Ideploy them? When making the last turning before the approach? Just a few feet before touching ground? Besides that, at what speed should Itouch ground? Imean, when not using flaps, Ijust cut throttle and let the plane go down, but a guy at the field told me that with flaps Isuppose to approach faster, that doesn't make sense to me, but Iactually don't know how to do it...
Any advice? Thanks!</span><span lang="EN-US" style="font-size: 10pt; color: navy; font-family: Arial; mso-ansi-language: EN-US"><o></o></span></p>

If you have the flaps set correctly, you should not experience any super drastic change it flight characteristics. I ahve flaperons not acutal flaps on my planes. I usually deploy mine on the down wind leg before the final turn. You dont want to find out that something isn't right on the final approach. I take off with flaps down as well. As far as landing speed, alot depends on type of plane, stall speed and CG of the plane. What works for me is, once I taxi out to the runway I adjust the throttle trim just below allowing movement of the aircraft. This still allows me to fly slowly, but keeps the speed up a tad on landings, and prevents the engine from over loading with fuel if I happen to cruise at idle for any extended period of time. If I remember correctly your plane likes to be landed hot (with a little speed)

well actually when Ifirst got this plane, Iwas told that Ishould land with a little of trottle to avoid stall, but Iland it almost like it was a trainer, just cut throttle and let it go down.

Flaps do not MAKE a plane fly slower, the ALLOW a plane to fly slower.

In other words, if a plane normallt stalls at 25mph, you need to approach at about 30mph and let that last 5mph bleed off as you flair (These are just approximate numbers)

The same plae with flaps will lower the stall speed to... Let's say 15mph. Now, you can approach at 20mph instead of 30mph

As for deploying them, I generally do it on the base leg. Bleed off as much speed as possible or the extra lift will cause the plane to balloon. In any case, the plane will usually rise a bit when they are first deployed. Just accept the extra few feet of altitude, and then fly the plane like you normally would.

If you over shoot the landing, just power up and go around, but only use about 3/4 throttle or the extra lift will carry the plane up like a homesick angel

You can either retract the flaps at a safe altitude and try again, or just leave them down and make another approach

You will soon get the feel for how much slower you need to approach for a nice landing.

Flaps tend to create more DRAG and LIFT.

Because of the increase drag on the plane, you normally want to increase engine speed a bit to compensate.

Your best bet is to learn how to use them via direct experience.

Do this.

Take your plane high, and fly a circuit. As you enter into the closer part of the circuit, drop the throttle to the point the plane flies level without loosing altitude.

Then drop the flaps and observe the results.

Did the nose of the plane balloon up?

Did the plane fly level then slowed down and started nosing down in a decent?

Practice this several times.

Then do it again, but lower the engine to a very high idle.

Again observe the results on the plane.


Take your plane up and imagine the runway is about 20 - 30 feet above the ground, but exactly where it is now.

Shoot a few approaches to your high level invisible runway.

Then do the same, but this time dropping the flaps before you enter finals.


You need to get used to both the change in characteristics of the plane as the flaps move up and down, and the low speed handling during approaches with the flaps up and down.

With flaps the plane can get slower, but if it gets TOO slow, it may drop a wing and nose over.

However usually the latter occurs at speeds much much slower than a novice expects.


Do not be tempted to chop the throttle completely on landings with flaps.

Except for trainers, this is normally not a good idea. You typically want a small amount of thrust to keep the plane moving forward while decending. And in winds you may need more for control.

Not sure I ever seen a homesick angel

Relatively light models don't need as much flap travel to get the job done as a heavier full scale plane.

You can have too much of a good thing.

Better to err on the conservative side, because you aren't sitting in the seat of your model to react as quickly to the need for more engine speed before the critical momement.

Don't flaps actually slow the aircraft flight speed? The reason I am asking is I remember when my dad and I used to go flying in his Cessna and he would apply flaps it felt like brakes on a car and it seemed the plane slowed speed dramatically. However, I was only about 10 or 11 years old at the time (about 45 years ago) so I could be wrong

In a Cessna 172 or similar, the flaps both create lift and slow the airplane down. The first notch creates a lot of lift and just a little drag. The third notch creates a lot of drag and a little extra lift. You can easily feel this in a full size aircraft, and the same principles apply to model aeroplanes.

In addition to creating lift and drag, flaps also stabilize the plane. With the flaps down, the wing produces more lift near the center (because of higher angle of attack). This means that the plane is less likely to drop a wing if you go too slow or pull too hard on the elevator. Stalls will be softer and more straight forward with flaps. Using flaps on takeoff, climbout and landing is generally "safer", unless you go way too slow with full flaps. There might not be enough engine power to recover.

When I fly models, I use the same procedure as when flying a full size small aeroplane: 1/3 flaps for takeoff, to create more lift and stabilize the plane. When to apply flaps for landing depends on how high I am. If I need to lose a lot of altitude, I might apply the flaps on downwind or even before that, to increase the sink rate. If it looks like I'm going to be short, I'll use only 1/3 or no flaps until I'm on short final, to make the plane glide better.

My rule of thumb is: 1/3 flaps for extra lift, full flaps for extra lift and brakes.

This is by no means the only way to use flaps, but it could be a good starting point. Different airplanes require different technique.

ok, I'll give it a try the next session, Thanks a lot for all your replies.

sandal said it best so far. One thing to remember is the main reason for flaps is to increase the angle of descent without increasing speed. The main thing to remeber is that if you retract the flaps to quickly without increasing airspeed you WILL stall. Remember this if you have a go-around, the plane will fly and climb with full flaps (R/C aircraft are overpowered.)

<p style="MARGIN: 0cm 0cm 0pt" class="MsoNormal"><span style="FONT-SIZE: 9pt; FONT-FAMILY: Arial; mso-ansi-language: EN-US" lang="EN-US">well guys, yesterday suppose to be test for the flaps but it didn't happen... my club was invited to a motorcycles event so we went, when we first got to the place, I told my friends "that signal is too dangerous for us, someone could hit it" and guess what?.. Yes! I was the dumb who hit that **** signal!!!!
my plane is now just 1/2 plane lol </span><span style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial; mso-ansi-language: EN-US" lang="EN-US">

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Hi ya'll

I don't wanna steal this forum but is there any advantage of flaps or not? are they good for low winger or for high winger?

Pros and Cons of flaps

I've had one plane with flaps. Actual flaps. The one thing that they were good for is doing some interesting loops.. full flaps, full pull on the elevator and it will just about loop in it's own length!! That was on a Goldberg Wildstick 40.

CGr.

I have flaps on a TF P51 mustang. They seem to work well when used. Half flaps for take off and full flaps for landing. I would land with half flaps to start with. When landing with flaps for the first time watch for getting the plane too slow on landing. Flaps I find also allows me to keep some power on which adds increased air flow over the flight surfaces. Takes away a little of the sluggishness of the controls when landing. I would also like to mention that if I'm landing in a stronger wind I will only use half flaps for landing, if the winds are very light then I go with full flaps. Makes for a little more even feel when landing in different wind conditions.

There are plenty of cons especially in the beginers context. They do increase drag as well as lift and the that ratio is dependant upon deflection. They will reduce the stall speed (slightly) and they will make the stall departure when it does occur much more dramatic.

This increased drag and lift will allow (cause) a much steeper final approach if the speed is kept low near the stalling speed and therefore your runway requirements will be slightly less. Now back to the real world Since when used in this way you are closer to a stall and a stall that will be more pronounced when it does happen therefore you will tend to use more power in the final approach and this power management unless done well, often results in no advantage with flaps using more runway and increasing the pilot workload during approach. This increased workload often when especially beginners are involved results in lots of approach accidents.

Flaps are the most desired thing the guys first want when learning how to fly because it sounds like a magic crutch, well its nothing of the sort and cause a lot of bad approachs and even accidents when you first start playing with them.

I am not talking about some overweight warbird or jet that sure may bennefit from their use and certain assumptions can be made about the pilot skills who will be flying them and not talking about some hot dog 3D plane where flaps are for an entirely differant purpose with an 'elevator to flap' mix. That is a very different mix from 'flap to elevator' for a very different purpose.

What made worse from every one just having to have flaps when their piloting skills are very much in the formative stage is what most are talking about is using flaperons because its so easy to do with modern radios and two aileron servos. Well the problem is flaperons are not as effective, cannot acheve sufficient deflections and will cause an even deeper departure when it does stall when compared to coventional dedicated flaps. Those are the simple facts and that always reads as a more difficult pilot challange.


John

Only just my opinion

I've had several models with flaps and I confess that none of them have been improved by them. Usually, the handling just goes to pieces with them down.
I'd guess that larger scale (1/4 and bigger) might get benefit from flaps, but it would depend upon the type.
The Robin DR400 had terrible flaps in the full size, so I can't see a model being improved! The Cherokee's flaps are tremendous on the full size, going from lift producing magic things to dangly barn doors that act like sky anchors. A Cherokee short field landing in a strong breeze is hair-raising for passengers because of the steepness of attitude and descent angle.

For me, the purpose of using flaps was to play at scale flying. So the flaps were used as per full-size practice. Intermediate flap at the start of the cross wind leg followed by full flap on final.
Fighter style flap selection would be at the start of the downwind leg, with a further stage at the start of the constant radius final turn with final stage flap as the turn is rolled out just before touchdown. Ideally, the throttle would not be touched after the start of downwind leg, using flap along with G for speed control. 'Hard to do in the plane, let alone on the ground!

Flaps allow you to make a steeper approach without increasing airspeed- all things remaining the same. Just fly around and deploy your flaps to see what happens. Use good judgement. Don't go screaming by at low level and drop full flaps into the breeze, now! Most model airplanes with props on the nose don't need flaps but are for 'fun'. Big props turning slowly can actually act as a speed brake. Sailplane folks use flaps more than others. The sailplane wings are very efficient and the designs so 'clean' that landing can be problematic at short fields and you only get one attempt! If you want to really learn to fly then get a sailplane. Have fun!

Thank ya'll for your deep insight and perception on flaps.

I have Hangar 9's P51 Mustang PTS which comes with fixed flaps. Either you can push them down to the last position so they would stay same at all times like fixed. That is the purpose of training as it was designed as a trainer. But I have been flying planes for the last 5 years and I think I'm beyond training flyer. I never used those flaps when I first got my Mustang PTS, now it's my second Mustang MKII so I don't use these flaps either. I was told by a flyer back in my home town that this flap would cause your plane fly with a nose up and he is a very senior flyer and back in 2005 I did not believe him then, and don't believe him now. Main purpose of fixed flaps to the down position is to make this plane fly slow, but as I did not use it before, I m not gonna use it now. I have been interested in flaps, but never used it and in near future I don't have any plane which may have flaps. Flaps I have left it to the future.

Mody