Need help on a flight basic

[myshoeistoobig]

Hello FT community,
I hace been learning on a Ft Cub and just started my 5 yo on a WMPF Tuff Cub. I have a similar issue on both planes and I am trying to solve it. I am currently flying a channel on both.
When I go to make a turn the nose will tend to dip down and will put me into a dive. I am not sure if this is a common problem. The main issue is that if I am too low I nose dive and wreck.
Any help would be greatly appreciated.

 

[mrjdstewart]

did you mean flying 3-channel on both?

how does the plane fly when level? do you still have to give the transmitter input to keep it level? can you take hands off controller and it will fly "hands off?"

if not i would look at your CG and trim settings. no matter what the plane, if you have it set up properly you should be able to take your hands off the controls without panic. the plane should continue nice and level.

you also need to remember that when in a turn you lose lift, make sure that once you initiate the turn that you then return to center stick and then give up elevator input to compensate for the loss of lift.

hope this helps,

me

 

[evranch]

This is an issue that happens to the real Cub as well in an uncoordinated turn. Adverse yaw - your high wing is dragging you into a slip and then one of your wings is beginning to stall. If you watch closely, you'll see your nose is first going up, out of the turn, before it begins to drop. You should add rudder into the turn if you have it. If you are flying a rudder/elevator 3ch setup I'm no help as I've never flown that style.

All planes tend to lose altitude in a turn so you want to pull up gently on your elevators through the turn. If you have no rudder or don't feel comfortable with the left stick, pulling a bit harder will compensate and keep your nose up. "Bank and yank" is a legitimate 3 channel control scheme.

I suspect you might be trying to fly slowly as you are learning. Flying slow is actually hard. Going into a turn with too little airspeed can easily result in a stall. Don't try to turn too sharply. Make some big gentle circles. I don't know the FT Cub in particular, but Cub trainers tend to be slow, draggy and underpowered. Don't be afraid to throw some throttle at it.

Stall recovery:
The Cub should not go into an unrecoverable "dive" but your nose may drop and you might lose altitude. If you are falling and have no control, you are in a stall. You want to level your wings and actually give down elevator to pick up airspeed. Then you can increase throttle and pull up. If you are too low, you will meet the ground before you get that airspeed - so they always say that beginners should fly "two mistakes high".

In a low altitude panic in an RC plane you can often do what you should never do in a real airplane - max throttle, yard up elevator and let the prop drag you up. RC planes are vastly overpowered compared to their real counterparts and the prop wash will give you enough airflow to pull up. Try to avoid doing this unless you think you are going to hit the ground, it's bad practice.

 

[Flying Monkey fab]

Okay, this is an easy one for me even though I'm new to RC.

I don't know your plane but yes, this is almost universal. Most of the time unless you have execs power or lift and are using gyros you will have to move more than one control at a time.

In the case of a turn, (( oh I see @mrjdstewart is fast!)) you lose lift so you will need to come back with the elevator a bit and in some cases add a bit of power.
I tend to lead with the elevator just a bit that way you are not ever recovering from a nose down situation.
Damn, just lost the interwebs, finishing up on the phone. I'll come by later and provide a diagram.

 

[myshoeistoobig]

So on a 3 channel setup, (motor, elevator, rudder) should I program a mix in the rudder to include elevator? Or as flying monkey suggested, give a little up before turning?

 

[evranch]

No, don't program a mix. This is a piloting skill that you need to learn, as you will be operating all three surfaces independently later on.

If you want more practice and less crashing, I would recommend trying out one of the many simulators out there. Picasim is free, runs on a phone or tablet, and uses the touchscreen as the controller so you don't have to worry about hooking anything up. You can see exactly the effects that rudder, elevator and ailerons have on the airplane. Give it a shot!

 

[mrjdstewart]

don't mess with mixes yet, just know in your head that this is going to happen, be prepared, give some throttle or elevator (your choice), and fly through it.

you didn't answer my question on how the plane flies "hands off" so i worry you have never taken your hands off to find out? if that is the case then you need to go back to the plane setup. get someone to help you while you fly, they can see what inputs you are putting in and even help click trim for you as needed. this allows you to focus on plane and be able to give verbal commands on what you need for trim. let them do the work while you fly.

let us know,

me

 

[Hai-Lee]

So on a 3 channel setup, (motor, elevator, rudder) should I program a mix in the rudder to include elevator? Or as flying monkey suggested, give a little up before turning?

Avoid mixes at this time. Your problem appears to be that you are trying to turn tightly one a 3 channel, (rudder/Elevator), setup. If this is done at too low a speed a phenomena called, (Dutch Roll), will cause the plane to quickly roll hard and head towards the ground. With a 3 Channel setup with dihedral you should operate the rudder gently at slow speeds when close to the ground. Experience is the best guide in this but do not use coarse rudder at low level and speed.

Have fun!

 

[Flying Monkey fab]

There is a time and place for mixes (I'm not there yet) but this is not one of them. You just have to fly the airplane,, that means moving whatever control needs moving at any point. The only control of the primary four that can sometimes sit is power but overall you need to be ready to adjust any of the four at any point.

 

[Merv]

I agree with the above, adding a bit of up elevator in a turn is normal pilot skill to learn.

Air speed may also be a factor. It’s normal to lose speed in a turn. The sharper the turn the more speed you will lose. If you are flying slowly, just above stall speed. Your turn is doomed from the start. If you are low you will crash, no chance for recovery.

A stall (not enough air moving over the wings to create lift) can also happen in wind. If you are flying into a 10 mph wind with a ground speed of 5 mph your air speed is 15 mph. When you turn your ground speed will drop a little say to 4 mph BUT your air speed drops from 15 to 4 mph almost instantly.

Yes try some up elevator, also try flying a bit faster and a bit higher. A wing stall at 150 feet is no big deal, a stall at 15 feet is doomed to crash.

 

[myshoeistoobig]

Thank you all so much for the help.
Sorry MrJd, it flies fine when I am hands off. I always check the CG before I launch, the control surfaces are in line with the surfaces.The main issue is when I go to make a turn.
The two main points I am seeing is I need more speed before I turn and I need more altitude so that I can recover.

 

[buzzbomb]

Thank you all so much for the help.
Sorry MrJd, it flies fine when I am hands off. I always check the CG before I launch, the control surfaces are in line with the surfaces.The main issue is when I go to make a turn.
The two main points I am seeing is I need more speed before I turn and I need more altitude so that I can recover.

I just read through the thread and they are also saying that you might need to add some up elevator on a 3ch set up. It'll help keep the nose up in a turn. Maybe no need to recover. I've been practicing that quite a bit with a TinyTrainer in Phoenix RC.