Best way to turn??

[aledmb]

I thought I knew how to land or make turns, until i had to land

on a pad. Then I was screwed, or I thought I could circle an

objective, until I had to do it and maintain situational awareness.

Its tough. But practice, practice, practice.

 

you mean approaching something in spiral?

that sounds simple to say and try, but a pain to achieve.

i'm trying this to land the chopper every single day.

 

when i get it right, it rocks!

otherwise, the ka turns into 50 pieces...

[Jack57]

Due to the weather vane effect the helicopter should need little if any pedal input to keep it balanced during forward flight, including banking. In a single rotor helicopter with anti-torque (tail rotor) however you will need pedal input until the weather vane effect overcomes the need for it. Not so for tandom rotors. Chances are, many of you are in fact fighting the AP. Hit A-LAlt and see how much sweeter she flies :joystick:

 

In theory you shouldn't pull back on the cyclic during a level banked turn - you should maintain height and speed with collective. IRL, the fact is that is you will more often than not use cyclic, collective and pedals to acheive your turns, depending on the situation and what you are trying to acheive. Pedal turns are the order of the day for tight combat manouvering :pilotfly:

Try to think of the helo as a flying disc and the fuselage as being dragged along for the ride and don't be restricted by too much theory :smartass:

 

Jack. CPLH

[aledmb]

Try to think of the helo as a flying disc and the fuselage as being

dragged along for the ride and don't be restricted by too much

theory.

 

nice thought.

[EvilBivol-1]

From reading the comments of pilots on the Russian forum, I can confirm AirTito's instruction to use the pedals to keep the ball centered. Vortex didn't say "don't use pedals," he said you should use them to keep the helicopter balanced. Not being a pilot myself, perhaps Vortex should explain exactly what that means.

[Frederf]

This talk about not pitching up to turn makes no sense to me. If I just bank then my lift vector with just have a horizontal component and I will be dragged sideways with no heading change. There must be something to add some "behind me" lift vector component otherwise there's no reason for the heading to change.

[slug88]

This talk about not pitching up to turn makes no sense to me. If I just bank then my lift vector with just have a horizontal component and I will be dragged sideways with no heading change. There must be something to add some "behind me" lift vector component otherwise there's no reason for the heading to change.

 

That's where the rudder input comes in. By keeping the sideslip indicator centered, you're converting the horizontal slip into a heading change.

[Stingray]

Thanks for the link, going to try out these proper turns,

 

Stingray

[aledmb]

hey, i'm reading that canadian flight training manual, just to get

acquainted with the basics, and found this snippet on lesson 3:

 

TAIL ROTOR PEDALS

The purpose of the pedal controlled tail rotor is to counteract
the torque effect of the main rotor, to control the heading of
the helicopter during hovering flight, and to initiate turns while
in the hover. It is not, however, used to control the heading
while in cruise flight, but only to compensate for torque. This
puts the helicopter in longitudinal trim so as to maintain
co-ordinated flight (Figure 3-3 refers). Some helicopters have a
‘ball’ to assist you to keep in co-ordinated flight. This is a simple
spirit level device, if the ball is deflected to the right, apply right
pedal until the ball centres and vice versa.

[url]http://www.tc.gc.ca/civilaviation/general/flttrain/planes/Pubs/TP9982/Exercise3.htm[/url]

so, in single-rotor helicopters, the pedals should not be used

while at speed because they are, in reality, anti-torque pedals,

commanding an anti-torque rotor. but the ka-50 doesn't need

anti-torque pedals. it has a rudder like fixed-wing aircrafts do.

so, in my opinion:

 

1. if you apply the LEFT pedal, the chopper should turn LEFT.

 

2. you MAY use the pedals to control the heading while at speed

(keeping level flight, if desired), as in a fixed-wing aircraft.

 

i don't know if the discussion was already established for you guys,

but i would like to hear your opinions about that comparison.

[Frederf]

That's where the rudder input comes in. By keeping the sideslip indicator centered, you're converting the horizontal slip into a heading change.

 

Ah much thanks.

[arneh]

If I just bank then my lift vector with just have a horizontal component and I will be dragged sideways with no heading change. There must be something to add some "behind me" lift vector component otherwise there's no reason for the heading to change.

 

The helicopter will weather vane into the direction of flight as soon as you get some sideways velocity. And the faster you're going the stronger the effect.

[Vortex]

Okay obviously this has confused a lot people, so I have written up a simple (but long) explanation about turning in a conventional heli. Now for those wondering about the KA50, I have never flown a co-axial nor do I know the theory, that's why I stated my interest at the beginning of the thread.

 

Lets get back to why we think we need to use pedals to turn in. In a plane using the ailerons to initiate a bank creates a yawing moment, this is because the drag created from the aileron trying to lift a wing is greater than the one trying to lower the wing.

 

 

In this scenario the nose of the plane will yaw left.

 

To compensate for this yawing motion, right rudder pedal is applied.

 

Now this is where people get things wrong. The rudder pedal is not used to "tip" the plane into a turn, but simply provide an equal and opposite yawing moment to the ailerons. More aileron = more rudder input needed, it's directly proportional.

 

In theory the nose should stay where it is and balanced flight occurs.

 

Now lets look at the conventional helicopter side of thing (important, governor imployed to keep things from getting confusing). When initiating a bank you apply cyclic, this does not create a yawing moment (very minimal and effectively nothing). Easy, we don't need to go compensating for it with anything!

 

Hence no torque pedal is required for turn in.

 

BUT now we now have a problem! Lets look at the vector diagram from a link already posted by JHepburn

 

 

 

 

As the disk is tilted it is creating less "vertical" lift, to maintain height we need to increase the component of lift. To do this we raise the collective. PROBLEM, we have now creating a yawing moment, thus we NOW need to use the pedals, specifically the antitorque pedal. This is the left pedal for a conventional heli.

 

Now lets turn left. We put a left input into the cyclic, start raising the collective to compensate for the loss of "Vertical" lift and input left pedal to correct the yawing moment created from increasing engine torque. Seems simple enough and almost just like a plane.

 

So lets turn right then. Input right cyclic, raise the collective and input left pedal. YES I meant left pedal, this is where fixed wing pilots struggle at first. If you input right pedal here you invoke an out of balance turn and things go pear shaped.

 

Right, I hope everyone understood that.

 

 

Let's move onto why you do not pull back on the cyclic in a turn if you want to exit it at the same height and speed.

 

Getting back to the Vector diagram above you can see that to maintain height you need to raise total lift somehow. Starting already in a turn, lets pull back on the cyclic then. Up goes the nose and so does our lift, great problem solved! But wait, our speeds going down. And if you look at our tracking our turn is not O shaped but infact has a radius that is ever decreasing. We are in effect flaring, just at a banked angle.

 

Lets try that again, but lets raise the collective instead. Up goes our lift, and providing we maintain the same attitude, our speed remains the same. Our track remains a perfect circle and we can maintain this height, angle of bank and speed as long as we want.

 

For those wondering why

 

If I just bank then my lift vector with just have a horizontal component and I will be dragged sideways with no heading change. There must be something to add some "behind me" lift vector component otherwise there's no reason for the heading to change.

If you maintain balance then the nose will lead into the turn. If you don't you will be skidding (like a car skidding straight ahead in a turn). This is what confuse people again, as obviously you need to input into turn pedal right? Wrong see above about the right turn, that's why when talking about pedals in a conventional helicopter (conventional in the sense of a single disk, not main rotor turn direction), they are used simply to keep balance, you make whatever input is needed to maintain it.

 

 

Now obviously I have simplified things, but I hope it helps some people understand what I am talking about.

[JHepburn]

Very interesting, thanks Vortex! So should the increase in collective cause attitude to remain constant, or should we plan on giving a little pull to compensate for a falling nose during the turn?

 

Thanks!

 

Jeff

[Vortex]

Yep that's part of the more advanced description. Your nose will not drop during the turn simply because you have banked. It will drop when you increase collective, so only a little cyclic is needed to counter this effect and keep the nose at the same attitude.

Edited January 3, 2009 by Vortex

[Stingray]

wow, this thread had a huge impact on my flying ability in the game, even after only playing for 30 minutes today after reading this thread. Thanks everyone

 

Stingray

[RvETito]

That's all good and well known but how do you counter side slip when you bank the helicopter? Because typicaly pilots train (well at least flying russian helicopters, regardless coax or classic) to turn with the velocity vector being in the plane of symmetry or in two words with zero side slip. In coaxial helicopter you have independance of the controls- change of collective doesn't require pedal input for balance. So when you bank the Ka-50 and raise to collective to increase lift (component opposing gravity) you don't need the pedals to balance torque. They are rather used to counter the inevitable side slip caused by the bank. Again, this is only for coordinated turn. You can fly with no problems with 90 degrees angle of side slip if you wish. The word is about standart requirements for flying tecniques. Having the velocity vector in the plane of symetry is crucial for weapons employment, that's why it's so important for combat helicopters.

[Reticuli]

 

So lets turn right then. Input right cyclic, raise the collective and input left pedal. YES I meant left pedal, this is where fixed wing pilots struggle at first. If you input right pedal here you invoke an out of balance turn and things go pear shaped.

 

 

That's only if you don't want the collective increase to assist the turn in a conventional western helicopter. Otherwise, it's helping coordinate it.

 

The biggest weirdness in all this for most people I think is usually the thing you mention about not pulling back on the cyclic, unless you just want a very small, decelerating turn...or that pushing the cyclic allows you to increase speed in a turn, though it widens it. Very counterintuitive.

 

Some weird, wild stuff.

[ThunderChief]

You all left out the most important question:

 

Why does the heading change (the turning start) when you bank the helicopter (or plane)?

 

I mean you could expect it simply starts moving sideward right? But obvisouly banking will induce some "forces" causing a turn. And here we are: Those "forces" are not exactly what you need. They are too weak. You need to add some yaw to keep the turn coordinated.

 

Its easy to explain why:

 

When you are flying a coordinated turn, those "forces" will be zero, they only exist when you turn is not coordinated. This is because in a not coordinated turn, the airstream (?) will NOT "hit" your helicopter / plane directly from the side, and this actually causes the turn. But you don't want this to happen, and thats why you use your rudder.

 

BUT

 

On airplanes sideslip will reduce the lift of the wings, and can cause a stall even if you are well above the stall speed. This of course won't happen to a helicopter. So you can very well fly an uncoordinated turn if you like it. I like coordinated turns. In fact I like to use even much more rudder than needed, because you will point the nose faster into the new direction, and thus you have SA faster.

[Vortex]

That's all good and well known but how do you counter side slip when you bank the helicopter? Because typicaly pilots train (well at least flying russian helicopters, regardless coax or classic) to turn with the velocity vector being in the plane of symmetry or in two words with zero side slip. In coaxial helicopter you have independance of the controls- change of collective doesn't require pedal input for balance. So when you bank the Ka-50 and raise to collective to increase lift (component opposing gravity) you don't need the pedals to balance torque. They are rather used to counter the inevitable side slip caused by the bank. Again, this is only for coordinated turn. You can fly with no problems with 90 degrees angle of side slip if you wish. The word is about standart requirements for flying tecniques. Having the velocity vector in the plane of symetry is crucial for weapons employment, that's why it's so important for combat helicopters.

 

That's when you use the pedals to keep in "balance". But by the very nature of a helicopter you will not always need to apply pedal when initiating a turn. It's not at all like with fixed wing where you always apply pedal while applying aileron.

 

It took me a long time to stop automatically putting pedal in when initiating turns, and until that time my turn-in was sloppy and unbalanced. Once I started leaving the pedal alone until it was required for balance, turn-ins became crisp.

 

As my instructor always said when referring to pedal movement during any training excerise "I cannot tell you how much pedal, or even which direction" "You just put in whatever is necessary, as it's always different".

 

Regarding the KA50, it's interesting that it's very similar to fixed wing. Also I wonder how much that enormous mast and centrifugal forces effects things.

[d0ppler]

Thanks Vortex. That cleared up a few things for me!

[RvETito]

Yes, coaxial helicopters are much more "natural" for flying. Once a pilot put his hands on coax he would never think about single rotor anymore. At least I don't know such person. The mast mostly affects drag, nothing extraordinary with the centrifugial forces.

 

You still didn't answer me how you counter the side slip caused by the bank..

Edited January 3, 2009 by =RvE=Tito

[Vortex]

Okay. When I look that mast I always feel for the engineers, two times everything to maintain.

[RvETito]

You feel that right ;) It's a pain in the a.. to remove and install it but once properly adjusted all it takes is grease. A lot of it ;)

[d0ppler]

Okay. When I look that mast I always feel for the engineers, two times everything to maintain.

 

However, the engineers don't need to worry about the tailrotor ;) But I guess it's "worse" being an engineer for a coaxial helicopter than a conventional chopper with tail rotor. :)

[RvETito]

You guess wrong, big time :P

[r-unit]

I dunno about the rest of you, but i've pulled off some very crazy manouvers in the KA-50. Blade collisons are rare these days but i'd like to give you some examples of manouvers that have worked for me with great ....... courage ?? muhh ahhaha. Here we go.

 

#1 Dive and Reverse direction, Hi speed.

Say your at 800p, you being pursued....... Drop collective and roll the shark upside down and slowly pull back on the stick, keep it nose down untill you get your overspeed warning and start pulling up. If you don't pull up to hard, you will pull it off and not have a blade collision or damage.

 

#2 Hard Turn right or left when being chased.

Ok one of my personal favorites when i'm being chased or need to change directions ASAP. Drop collective and roll the shark almost 90 degrees right or left... the forward airspeed and low pitch of the blades will allow you to pull very hard on the controls with out a blade collision. once you've turned around you airspeed will be low and you will surely get a low Rotor RPM warning, give it not even half collective to recover. Your generators may kick off line when you get a low RPM warning but hey, if you in combat it's not going to matter.

 

These are not textbook Black Shark moves, these are my moves, and have worked for me.

 

Happy Hunting.