Falling out of the turn... help!

[FlyingRadioWaves]

So, indoor flying Sunday nights...
And I've noticed a problem that I may have over looked when flying outside. I know it takes practice, but I am missing something here...

I will be in forward flight, life's good. I understand the mechanics and aerodynamics of the turn... I tilt my chopper over to the left, slight bit of elevator, rudder to swing tail over and a wee bit of collective. The chopper makes the turn, but then makes a bee line for the ground and usually I end up skid landing on my nose. This "action" is with all my choppers, so I believe it is me.

When I turn to the right, the chopper balloons, or skids to a crash. Left turn is almost always a skid crash. Yes, I can complete a circuit, but its far from level? Any suggestions? I don't really have a simulator, just my choppers. I have a basic FS One, but I need to know how and why this is happening. I hope I can out fly this issue.
Thanks for your time and thoughts. I know this is covered so many different ways.

[gitbse]

Practice.
Knowing how the mechanics of how a heli flies and how to actually control it are two different things. Circuits are all about the disc angle. Watching the disc is how you should learn to fly, rather than watching the body. It will unlock alot of things, and you will become a better pilot, but it will take a little getting used to at first.

Sounds like left turns you are simply over banking, and there's no lift left. Or at least not enough speed to make up for the downward disc angle. Going to the right seems like you are underbanking, and just pulling too much elevator. It's all about watching the disc angle.
There's a magical "slot" that helis will do very basic, and very extreme 3d at. It's roughly ~45 degrees. Anything from circuits, to tic tocs, and so on. You will only be able to find that slot effectively, however if you watch the disc while flying instead of the body.

[HeliSmith]

When you are flying in forward flight the disk is tilted forward. If you turn your tail slightly keeping the nose slightly down while keeping your aileron flat you will turn and the helicopter will take a new direction. So in fact you do not need to bank in order to turn. You need to bank in order to do hard turns, just like a race car does. Although I do bank slightly in slow turns also, this comes with practice and gives you a clean precise circuit.

Hard banking is for doing sharp turns, or high speed circuits. In these cases you would want to bank.. But if you do not exit the bank at the proper time your helicopter will slide sideways into the ground.. Properly referred to as sliding..

When I bank my helicopter I am using elevator to perform a hard bank. For example if I am in a tail first inverted hurricane, my favorite, I am using down cyclic or elevator back to actually steer. Aileron and collective are being used to keep from hitting the ground.

P.S. Get a sim

[Steve Graham]

Skidding, sliding, steering, banking, slipping and crashing oh my!

Sorry, couldn't help myself.

What this conversation needs is a glossary. Without it we will never communicate in any meaningful way.

Bank angle: The angle of the disc in relation to the horizon.

Heading: The direction that the nose is pointing.

Flight path: The direction that the aircraft is traveling in.

Level flight: The aircraft is neither climbing nor descending.

Straight flight: The aircraft is tracking a straight path through the air.

Rate of turn: The number of degrees per second that the heading is changing.

Turn radius: The size of the arc described through the air by the aircraft. In reality the distance between the center of the circle and the flight path.

Pedal Turn: A normally zero or very slow speed turn in which the rudder does most of the work of bringing the aircraft to a new heading. This is something our helis can do that normal aircraft can't. They can fly at any airspeed, even no airspeed at all.

Skid: A condition where too much rudder is used and causes the forward most, in terms of flight direction, part of the aircraft to move inside the track of the aircraft. This is analogous to a car on a track. The skid is the safer given a choice between a skid or a slip. A skid tends to drive the aircraft to the high side of the turn and hence into a climb.

Slip: The opposite of a skid in that not enough rudder is used to keep the heading in line with the flight path. The heli will tend to begin sliding inwards towards the center of the circle and therefore also lose altitude.

Coordinated Turn: A turn completed in forward flight where the bank angle and rudder are coordinated in order to achieve a dynamic balance. IOW's, The flight path and the heading are one and the same. The aircraft is neither slipping nor skidding and the G forces applied are directly in line with the main shaft. The occupants of the aircraft feel no sideways load components. At slow speeds the bank angle required for a constant rate of turn for arguments sake lets say 10 degrees per second is fairly low. As airspeed builds the bank angle required for the same rate of turn increases. This is simple physics and has been explained much better than I can in many basic texts on aerodynamics. I want you to just recognize the interplay between airspeed and bank angle as they control turn rate. When the airspeed is very low the turn rate is dictated largely by rudder and very little bank is required for a given rate of turn. I see this mistake all the time. The heli is moving fairly slowly which is good for a beginner and a turn is initiated with aileron. An obligatory small application of pedal is applied but nowhere near enough. The heli begins to slip and eventually starts to plummet earthward. The pilot in an attempt to save the day gives a big yank on the elevator which only serves to tighten the turn and increase the need for rudder even more. It is usually around this time that the pilot runs out of altitude and ideas at the same time with a resulting hit to the wallet. Remember this "the lower the airspeed the more rudder you will need"

Steps for performing a coordinated turn: The aircraft is in forward flight at some given airspeed. The pilot must choose a turn radius that meets his needs. Once again turn radius is determined by bank angle and airspeed. If he wants a nice big arc than he will choose a relatively small bank angle. For a sharp turn a relatively larger bank angle is needed. The higher the airspeed the higher the bank angle required for a given turn radius. The pilot rolls the aircraft into the turn using aileron. Now we must talk about lift vectors. When the aircraft is level all of the lift acts vertically. When the disc is tilted so as to bank or pitch the aircraft a small portion of this total lift component begins to provide translational or sideways thrust which begins to move the aircraft forwards, backwards or sideways. At the same time a bit of the vertical lift component is lost. In forwards turning flight this small sideways force is what begins moving the flight path into the turn. The slight loss of vertical lift is countered with a compensatory bit of back pressure on the cyclic stick. In aircraft with a vertical fin or a heli for that matter with it's gyro set in rate mode the tail will tend to weather vane into the turn. The rudder can be left largely alone and the aircraft will turn nicely with no rudder input. I know this oversimplifies things and doesn't account for things like adverse yaw but it works for the purposes of our discussion. The problem is our helis are generally operated in heading hold mode. This means that as the aircraft begins to bank and naturally flow into a turn with rudder the gyro will sense this and apply opposite input in an attempt to hold the heading that the aircraft was initially on. This induces a slip. Unintentional slips are bad for the reasons I previously explained. So any time the heli is brought into a turn in forward flight your must 1. Bank the heli. 2. Apply enough back pressure on cyclic to prevent a descent and 3. Use coordinated rudder to keep the tail behind the nose.

Rudder is a fundamental skill in flying helis and especially important for folks transitioning from airplanes. I was doing some training a while back with a friend who has been flying planes for years. Shortly after beginning I looked over at his TX and he was resting his left thumb on the side of the radio. I landed and we had a "come to Jesus" moment about the simple fact that if you want to fly helis you WILL become intimate with the left stick.

These terms may seem academic and unnecessarily long winded but without them our conversation may as well be babel.

I disagree on anything magical about bank angle or heli flying in general. What's needed is a fundamental understanding of the physics of flight and the ability to predict the need for inputs and watch the aircraft and give it what it needs in any given situation.

[FlyingRadioWaves]

Thanks Steve! Your reply was not too technical or long winded and it makes sense. I can almost feel my transmitter (tx) and sticks, trying to emulate the flight at my desk.

Thanks also to the others for their suggestions. I will keep this in mind when I fly next time. Yeah, a simulator (more modern than mine) would be an asset, but I keep spending my coin on choppers...lol... yeah, I know!

[ozsteel]

As Steve said...

1. Bank the heli,
2. Apply enough back pressure on cyclic to prevent a descent, and
3. Use coordinated rudder to keep the tail behind the nose.

Simple...? But only with lots of practice.

[newhelliguy]

Graham

Do you have an audio version. Great write up

[rojack]

You know, even knowing all the rules of how to do a banked turn, having it memorized and understood, and even being very good at turning a plane in FFF, I still used to find myself in the same situation as the O.P. when flying helis fast in tight turns.

Once I started practicing slow piros, I started to figure out that what I was doing wrong all along with helis was correcting the wrong way while in a tight, fast, banked turn, like when working on hurricanes. Typically this would happen once I was heading towards myself.

When moving fast enough, you don't have time to think of what the rules are and which way you should move depending on what part of the heli is facing where. Your fingers have to know what to do, and react properly, or "pre-act" (anticipate) in fractions of second, and this of course comes through lots of practice.

I know it's been said, many times, many ways...
practice those slow piros!

Your mind has got to know which way to correct for drift, instinctively, in any orientation.
Well that's my take on it anyway!

[newhelliguy]

One thing that came to me with time is when I make a wrong input I dont panic and watch it crash I just reverse the input.
We had a guy that got really good and you could see him put in a small input then correct if it it was wrong

[whitehedr]

Nicely stated Steve. I wonder what pilot ratings you hold.

RWW

[nu66ie]

Just wanted to toss this into the discussion as it has gotten me twice now.

First, when learning FF, don't forget to become proficient in CW and CCW equally. It is easy to get into one direction and master it and then try the other direction and be lost.

Second, I spend most of my flights flying inverted, backwards, short FF bursts, or just twisting through the sky. On two occasions I decided to fly some FF circuits and I about crashed because I no longer had that orientation locked in. It was the funniest / most frustrated feeling I've had while flying. Now I spend sim time daily doing just FF. It comes back very quickly, but having to think about it in the middle of a banked turn and the heli is going somewhere else is a recipe for disaster.

Just my .2

[FlyingRadioWaves]

I've had a good few flights now, keeping in mind the tips shared here, without falling out of my turn.
I needed a little more back pressure on the cyclic (elevator), way less bank angle (for the given speeds, that's where practice comes in) and of course, rudder control. But, being aware of what to look for goes a long way when you are practicing.

The slow piro's are my Christmas break project. I can do those in my living room. When I get to fly indoors (at the indoor soccer pitch), I'm stretching my legs!

[ChitownMatt]

I am an intermidiate flyer myself, and my suggestion would be to just slow down and stop using the bank alltogether.
Practise flying side-in back and forth right in front of you using rudder only to rotate the bheli at each end. (you will need to make corrections on the cyclic to keep it flat, of course.) As you get faster and faster, the bank and elev control will start to happen naturally.
Learn to turn slowly with the rudder first and the banking will take care of itself.

[bladesr]

Just practice on sims a thousand times and it will suddenly "click" !!

[gitbse]

Originally Posted by bladesr

Just practice on sims a thousand times and it will suddenly "click" !!

+1
Sometimes it can be like that. Learning comes in two ways with flying these things.

1. Lots of practice, over time your are able to execute something gradually better. Every time you try it it gets a little better. Different orientation circuits were like that with me. Took quite awhile to get them all down.

2. "AHA!!" All of a sudden something will click. You will be either practicing something, and it will hit you all of a sudden, or something else will squeak out that you couldn't do before, and bam, there it is.

Also, it's kinda wierd and doesn't always happen, but sometimes when you give it a little break, something you've been trying will actually get better when you come back to it. It happens to me every once and a while, when I take a few days off from flying. It's almost like there's a skill inside of you "stewing" and when you come back to it, it's done. Too many days off goes the other way though.

[navigator2011]

I've totally had something like this happen to me! But I don't recall having the heli skid or slip as discussed above. When I had it happen, it was kind of like all of a sudden there was no lift, and the heli would just drop straight downward, no pitching forward or sideways, or anything like that. My natural response was to give a lot more throttle, the blades would bark just above the ground, and the heli would then rocket straight upwards, again. I just thought it was the breeze shifting across the disc as I began banking.

[HeliSmith]

navigator if the heli was falling straight down but while the heli is at an angle that means you were at 0 pitch or you didn't have enough headspeed. To say it another way if you have the disk of the blades tilted in a direction with sufficient pitch it will pull to that direction. It takes extra energy so if you do not increase pitch when you tilt your heli it will fall at an angle we refer to as a slide. We call it a slide because it increases speed on the way down becoming harder to correct by the second. Flattening out and applying adequate pitch is the answer for almost everything.

[navigator2011]

Hi Helismith, thank you for your reply. I am not quite sure how I could get into a 0-pitch situation. Are you saying that if I am flying forward casually (not fast or anything) and then I begin to bank and rudder into a turn without giving extra pitch, then it will slide as you described? I have noticed that flattening out and applying more pitch seems to help, and does ruddering harder so that the heli's nose is pointing in the direction of the blade disc tilt. But when something like this suddenly happens, it seems it's always second nature to just freeze the sticks in position.

[HeliSmith]

Yeah I think somehow you are not adding the pitch but I am afraid to advise you without seeing your sticks. It is hard to synchronize all three actions of a circuit also so maybe you are specifically having trouble there. The three you manage Bank=Aileron, add pitch and use elevator to actually turn. One thing you can do is make a recording of your sim session. Phoenix lets me do this and see my stick movements so I can see if I am doing weird things.

But imagine this. You tilt forward to cruise your heli forward but you forget to add more pitch. Does your heli fall straight down or does it go forward at an angle toward the ground? Using that basic knowledge it sounds like not enough pitch or too much tilt for that amount of pitch.

[navigator2011]

Hi HeliSmith, so I've flown a bit while being aware of your advice. I didn't encounter any situation where I felt I had to concentrate to follow your instructions, nor did the heli try to fall out of the sky. So, maybe I'm already doing things better, I don't know. At any rate, I never had any problem in the simulator, which is what led me to assume that the shifting breeze is the source.