opjose

Have you ever considered just using the "fuel tubing" trick?

That's a very small plane, and the "fuel tubing" trick is appropriate for it...

Fuel Tubing Trick:

Place a small washer onto the landing gear wire.

Next place a small piece of fuel tubing, then the wheel, (optionally another piece of tubing and yet another washer) then the wheel collar.

Adjust the wheel collar so that there is some pressure between the wheel and the tubing, providing some resistance to rolling.

The plane will still roll for takeoff but at landing it will stop far more quickly.

crasherboy

Rebuild the wing and install inboard flaps as the full scale has.

opjose

A bit of overkill with the .50. At worst you can dial in spoilerons and flaperons...

The 1.20 Falcon does come with the flaps though.

emeraude

the fuel tubing trick will make matters worse and the model will flip on its back on landing because of the momentum and unpaved landing strip ,what im looking for is a way to reduce the airspeed .

john

VeeAte

Scuse my ignorance, but isnt it stalling when it loses airspeed?

So anything that slows it down with the current configuration going to just do the same thing?

emeraude

veeate "stall is caused by the pilot attempting to fly the aircraft too slowly, or to pull up too quickly from a dive, or to turn too steeply. Each of these causes the nose to be lifted until the wing's critical angle of attack is exceeded" (wikipedia)http://en.wikipedia.org/wiki/Stall_(flight)

What it means is the boundry layer on top of the airfoil no longer sticks to its surface and the airfoil looses lift.so loosing airspeed does not necessarily always result in a stall provided it is above the minimum stall speed.what im looking for is a way to reduce the airspeed so that i can land slowly.My model is the same as the one in the image

opjose

That's not true...

It's how I get my plane down onto grass as well as pavement.

You should be coming in NOSE HIGH with spoilerons engaged.

This puts all of the stopping on the two wing wheels. No tubing is used on the nose wheel.

With the long nose, how on earth could the plane flip onto it's back?
You'd have to augur it in.

I've collapsed the nose wheel and landed on grass w/o ANY semblance of "flipping".

-

To slow the plane, spoilerons are a better bet than flaperons, because the spoilerons act to prevent wing tip stall.

Add a bit of elevator into the mix too, and if possible splay out the two rudders at the same time to dirty up the plane, and you'll kill airspeed quickly.

But remember engaging the rudders opposite each other, in EITHER direction tends to push the nose UP because of the design...

You need to counteract this with DOWN elevator when engaging the rudders as speed brakes.

emeraude

well i flipped mine twice .both times it was a straight forward landing .After rolling for several feet the plane flips over .Thanks for the info on spoilerons , ill mix in up elevator aswell and setup the flight condition switch to engage a few degrees up aielrons and elevator before landing on my Hitech eclipse 7 .One question though will the spoilerons induce a dive ?

VeeAte

Ok cool. Thanks for the info. I am still new to all this.

crasherboy

I still say rebuild the wing and install inboard flaps. I have around 100 hours of flight time in Cessna 150,152,172,and they all use flaps. A 152 Cessna with full down flaps can fly as slow as 40 mph. Without flaps 60 mph. With full down flaps you can safely land at 60 mph. Of course in a full scale one can feel how the craft is responding and take action [hopefully before you crash] to pick up a little speed or give it a little throttle ,or maybe a little of both. But in the RC world you don't have the luxury of being on-board to feel the pulse of the craft,which maks it hard sometimes to act before it is to late. The idea of crow looks to me like a great idea. That would be almost as good as a parachute being deployed. Back to the flaps. When coming in for a landing[full scale,Cessna 152] you slow the plane to around 80 mph ,then give it say 10% of flap ,you have to drop the nose a lot,at some point you put the flaps all the way down for the slowest landing speed. With out flaps you would have to fly 70 or 80 mph to avoid the posibility of a stall to close to mother earth. In short ,if the wind is calm you could land a 152 with full down flaps at 40 mph + a tad for mistakes. But with out flaps around 60 mph. See the difference? The model in question I am certain would respond in like manner.

gittarpikk

All of this brings to mind what the REAL problem is when landing a plane on a short strip. Yes, you can use flaperons (full length strip ailerons drooped for landing) or separate flaps/aileron with and preferably if your radio is a computer version then mix in some crow (where ailerons deflect up when flaps are downlike a crows-wing/tip feathers upon landing)...or....yes....OR learn to always fly the rudder as well, 100% of the time (yeah man, that left stick is very useful in more than just knifedge)

What I am driving at is I feel that if a person learned to fly "properly" then he will have flow at least one trainer early on that was 3 channel(rudder elev throttle) and if he took advantage of a small often overlooked segment of learning between the Rudder turned plane and the aileron turned plane, he could easily train both thumbs to track a turn simultaniously. As one progresses to more advanced manuevers, both thumbs are already moving to steer the plane and it is not hard task to just start thinking of what you want to do with the left thumb and not have to think what you are doing with the right one.. The "slip" is then nearly automatic and as full scale pilots have found since the beginning of time that that is the safest, cheapest, coolest and most controllable way to "slow er down" for short strips. Doesn't matter what/whose plane your flying then, it is easily done.

There is one observation about the slip manuever. Since I do those automatically (balancing the correct aileron amount with the correct rudder amount), my only thought is to automatically add just a bit of down elevator to counteract the ballooning effect the dihedral creates as one wing comes forward. No dihedral pretty much equals no ballooning effect but be ready for the sudden drop in speed which will tend to drop the nose a bit.

The above example is complicated by which mode/ transmitter setup you learn to fly on.To really take advantage of this system requires your first Rudder-elev-throttle trainer to have the rudder on the left stick with he throttle and the elevator on the right. When you "pick up" ailerons, you will automatically be using your right thumb and not have to reteach your right thumb to fly ailerons instead of rudder.

More advantages to this method is that you really don't have to concern yourself with engine right thrust as you can automatically think of adding the correct amount of right rudder stick to offset the torque.

Its a bit more elaborate to learn to fly this way and is kinda like flying helis with no heli radio nor gyro (which I have done as well but is a LOT harder) but you learn how to REALLY fly a plane and all the computer does is make you lazy. Crow though , is pretty much ENTIRELY a computer option.

jrpav1

My Feedback: (17)

One thing you guys are overlooking: Weight. If you can make the airplane lighter your landing speed can be slower with less risk of stalling. Also C.G. A "nose heavy" plane typically lands hotter than a properly balanced one. One last thing to consider is your landing technique. I have a G.P. SU-31 that weighs almost 15 lbs. (heavy as far as I'm concerned) and I can still bring it down in a fairly tight area with proper throttle management and by paying close attention to the attitude and speed. I don't use flaps or spoilers of any kind. Just skill.

John Pavlick
Team Black Magic, Tech-Aero Designs

mjfrederick

Agreed John. However, I got a Big Stick 60 ARF for Christmas, and I programmed flaperons (pretty good amount too, probably 15 - 20 degrees) into it just to play around with and it's quite fun what I've been able to do. Last weekend I was doing touch-n-go's, diving the plane to the deck with the flaps down, and settling it right in. Another fun thing was with them down on takeoff, all I had to do was advance throttle and steer with rudder. The plane took off and climbed out by itself. I don't need the flaps by any stretch of the imagination, but they sure are fun!

griesel

I just set up my Twist 60 with spoilerons to see if bouncing on landing can be cured. I tried 1/4 inch and 1/2 inch up on
the ailerons. 1/2 inch worked best. What this does is decrease the wing incidence which then requires the fuselage angle
of attack to increase on landing. On either a tail dragger or a tri-cycle gear plane if the rear wheel(s) touch first then the
angle of attack decreases reducing lift and the plane stays planted. Note the Maule ( an STOL light plane ) has flap
settings of -7 degrees ( flaps are high ) which are used to increase cruise speed. The setting of 1/2 inch is just under -7
degrees. I did a bunch of touch and goes alternating spoileron / no spoileron and the gallery had kind words on most of
the spoileron landings with no comment on the no spoileron landings. Some words of caution, take it up high when trying
this out and check out the stall characteristics. I did not find any major pitch changes like when flaps are lowered. Also
this technique requires more thottle on landing so be careful. This plane is also set up with CG @ 25% of MAC which some
consider nose heavy.

opjose

Yeah, spoilerons DO help... as does slipping into the landing as indicated above.... however the latter requires a very delicate touch and is not always doable.

A bit of spoilerons helps cure those hot landings.

buzzard bait

V8, the club member is right. Washout is extremely common on full scale aircraft, and models of those planes benefit from incorporating that scale feature. Mustangs, Zlins and even Piper Cubs all have washout. I'm about 99% sure Cessnas do too. Washout will allow you to slow down more before the plane stalls.

But this is no help for the original question because washout would compromise the inverted performance of a Stick or Sukoi. It's really for planes that usually fly right side up.

Jim

AA5BY

Changing the prop to a size larger and a lower pitch might help as well. Some smaller engines do not idle low enough and a higher pitch prop on a fast idler will keep speed up.

jay1st

Hi all,

I'm digging out this topic as I am willing to mod one of my airplanes.
It's a low wing trainer (lots if fun with it) with full span ailerons.

What I'd like to do is split them to have some flaps (or spoilers), so using 4 servos in total.

It has a 56" WS and the ailerons are like 3/4" wide.


So, what ratio should I use, 1/2 or 1/3 for the ailerons ?

Tnx

AA5BY

The quads on the Ultra Stick are about equal size. However, they are a lot wider than 3/4 inch and how much crow function is achieved by those narrow flaps is questionable. I'd think that the 3/4 inch needs to be expanded so that aileron effect is not lost by reducing them by half. Perhaps double the width and give it a try but set it up with considerable exponential for the first test flight so if more roll is needed, it is there but if not needed, then it wont be squirrelly around center stick.

BMatthews

Yep, not a good idea to split strip ailerons that are that narrow. It's far too narrow to get a really significant flap effect from the inboard portions and it'll slightly reduce the aileron response.

The best way around this would be to cut away and install new control surfaces so the new ailerons and flaps could be more along the line of 1.5 inches wide. Then you'll get enough effect to make the work worthwhile. At that point split the flap and aileron spans so they are equal on each side.

For just adding some lift for takeoffs and drag for landings you can drive both flaps with one servo. However if you want to play with coupling the flaps and elevator or play with crow and other options then a full 4 servo wing with all the mixing bells and whistles will be needed.

jay1st

Tnx,

I was already thinking of using the 4 servo solution, using full span ailerons while flying and the flaps for landing at lower speeds.
In fact it's becaus I am putting an OS 70 Ultimate in the plane supposing to have a 40-46 size in it.
But adding a bomb bay and some external pylons for extra bombs.