Good to be back

Been playing DCS A-10C lately, and I want to get back into black shark. Haven't played BLack Shark since July of 2009. I started playing BS again with my X52, as my Warthog is due to come any day now, sort of as a tearful bye bye :) to my X52. So any way, I am picking up the Black Shark just fine, I am in fact, playing it better than I did in 2009. I can enter a hover just fine ( although it takes time and practice ) I can trim just fine ( using combination of discreet press/release and hold it down method ) but I always seem to sideslip to the left when I am in forward flight. I've tried using right rudder and left cyclic, but it doesn't seem to work. Am I doing it wrong or something? Overall great sim, but just one tiny little prick. Thanks!

Happy comback :)

My style is - conclusions first, then the BS ;) (if I'm wrong here, correct it ASAP)

 

• AC flies in a straight line, there is no lateral acceleration and yet the ball is off center - gravity and AC bank is to blame
  
• the "ball in the center" is not your goal. Coordinated flight is. The ball is just a flawed instrument which might help you achieving coordinated flight.
  
• coordinated flight prevents excessive drag and all of the bad things which follows higher drag
  

 

 

 

Now the BS:

 

Gravity is the only thing I can think of :) The ball channel is U-shaped so if it's tilted to a side (AC flying with slight bank angle) even by a little it will be off center even when there's no lateral acceleration.

 

Also recently I asked myself "WHAT'S THE WHOLE THING WITH KEEPING THE BALL CENTERED?!" - in any AC. Certainly not to have all the instruments looking symmetrical and nicely. Let's do this on a fixed wing AC. Let's also ignore the details of what's happening when you just started moving the control stick to side. Let's say you are already in a turn. Now when you don't fly by the book you are either in skidding turn or slipping turn. In both cases you are simply facing the airflow with much greater fuselage cross section than in coordinated flight thus suffering from increased drag compared to the drag value in coordinated flight.

 

You've observed yourself that the praised ball has its flaws. What I would recommend is to, after you explain to yourself all the aspects of using turn coordinator, do some reading on this little fella on the windshield (Wikipedia calls it "yaw string" ...:smartass:)

 

 

... and compare it to this slightly bigger fella (the vertical one *) ...

 

 

And now here

 

IMO these fellas show what's important in coordinated flight better than the ball.

 

Finally you don't realize how much you missed if you haven't read this book:

 

 

 

* which do its job for horizontal plane obviously :D

O.K I don't get much of what you said. the Ka-50 doesn't have a sideslip indicator. And you probably mean to tell me I'm turning wrong too ( I just crank the stick to the right and press down the trim). If so, can you just simply tell me what control inputs keep coordinated flight and good turns? thanks.

Ka-50 does have a turn and slip indicator as the quotation mentions. It also tells wheather it's possible to maintain 'everything straight' in med/high speed flight. Try to read it again. And again. Don't skip the appropriate chapter in the FAA goodie.

After your homework is done you may rest assured that I will answer every question you ask that refers to the sources.

You can't tell what control inputs to maintain to achieve reasonably coordinated flight because it all changes dynamically. I'll try to record a track for you. In the meantime you can watch an in-cockpit video on youtube titled GEORGIAN Mi-24. Observe how he maneuvers the heli and whatch the vain sensors (small plates in front of the windshield).

Edit:

Oh, it's embedded in the quotation I posted. How thoughtful of me :D

@ Bucic,

Sorry i can't agree with your statements of the turn and slip Co-ordinator or "ball".

Quite simply this, is a very important piece of equipment.

Having the ball centered means you are in co-ordinated flight.

I am a professional pilot and some of what you have said is incorrect or misleading at best.

@ Bucic,

 

Sorry i can't agree with your statements of the turn and slip Co-ordinator or "ball".

 

Quite simply this, is a very important piece of equipment.

 

Having the ball centered means you are in co-ordinated flight.

 

I am a professional pilot and some of what you have said is incorrect or misleading at best.

I agree with Bucic's assessment; it seems to me that in an A/C with asymmetric lift, flying coordinated (velocity vector is aligned with nose heading) means flying at a constant bank angle, which means that the ball will be pulled to the side by gravity. What's our error here?

I agree with Bucic's assessment; it seems to me that in an A/C with asymmetric lift, flying coordinated (velocity vector is aligned with nose heading) means flying at a constant bank angle, which means that the ball will be pulled to the side by gravity. What's our error here?

Not entirely accurate.

In a twin engine aircraft, and lets use a prop plane to emphasize. With one engine shut down the thrust of the remaining engine over its wing will cause "asymetric lift". More lift on the wing with the live engine.

I can still fly this aircraft in balance (wings level).

Depending on the aircraft, angle of attack and amount of thrust used, this can have trade offs. (i can go into more depth here if you would like)

For navigation with asymetric thrust (simulated engine failure), we are required to fly balanced, wings level in order to minimize drift that can occur flying out of balance.

On a different note, from the first picture, i beleive Bucic may be confusing a turn and slip indicator with a turn co-ordinator.

We are mentioning turn co-ordinators and indicators. with respect of the KA-50, unfortunately it has neither. It is only an ADI with slip ball. On the right front panel its a standby ADI with slip ball.

There was this statement "You can't tell what control inputs to maintain to achieve reasonably coordinated flight because it all changes dynamically"

The first part is not true however the control inputs changing dynamically is. And this IS what the instrument is used for, for you to acurately judge the inputs needed for balanced flight and trim for such. Of course, constant speed and heading changes will necessitate constant different deflections of the controls.

Anyway, its all a moot point as the KA-50 does not have either an indicator or co-ordinator. It does have a slip ball and it is there for a reason.

And food for thought.

The KA-50 has contra rotating blades. therefore does it suffer from large amounts of asymetric lift?

Does the KA-50 in reality hover "one skid low" (with bank), is it designed to fly at cruise with bank?

My point is, the ball is not a flawed insturment, it is a very useful tool in both asymetric and non asymentric flight (provided you understand how they work)

@bogusheadbox:

Haven't you noticed that my quotation is specifically on Ka-50 case, with references to fixed wings only for theoretical basis purposes? And 2-engine ficed wing? Please, let's keep it simple and heli-only (at least in the conclusions department). I created that piece of info specifically for those who do not realize what's the whole thing with coordinated flight is about / newbies, it does not contain any factual errors AFAIK and I believe it served the purpose well because I don't recall much cases of a newbie asking additional questions after reading that ;)

There was this statement "You can't tell what control inputs to maintain to achieve reasonably coordinated flight because it all changes dynamically"

 

The first part is not true however the control inputs changing dynamically is.

Erm... that sentence was one-part :) If you have found some incorrect bit in it, please rephrase and highlight what you don't agree with exactly.

The only thing I agree with you on is the naming convention. But then the quotation contains no naming convention errors, so it appears :) Only my last post. The right naming convention is

turn-and-slip indicator and turn coordinator:

slip indicator = "ball"

And they are all: turn indicators, so I'll use that last one in all my posts in the future not to cause any confusion.

.

Seeing you askin questions about Ka-50's flying qualities makes me wonder are you even experienced enough with the Ka-50 to be discussing the specifically heli part of my posts. I don't mean to look down upon you (as I have few flight hours on my account either).

The ball IS a flawed instrument. You can only argue how much flawed (obviously more falwed for the application on helicopters). What you fail to understand is the solid logic that a statement 'ball is flawed' does not imply 'ball is useless' and certainly it does not imply 'ball is equally useless everywhere'.

So you mean that in some cases, the KA-50 cannot mantain perfect level flight?

So you mean that in some cases, the KA-50 cannot mantain perfect level flight?

If by "perfect level flight" you mean wings level with no slip, then in no cases can the Ka-50 maintain perfect level flight. You always have to choose between either bank or sideslip.

Sure it can. It can maintain level attitude. It can also fly coordinated. It can even fly in a straight line.

The big assumption here is that it can do all 3 at once.

First and foremost i am not trying to start a war or a "holier than thou " tug of war. So forgive me if my reply insinuated such.

And they are all: turn indicators

This is incorrect. Both perform differently. A co-ordinator is not an indicator. They can both portray the same information in certain parameters. You can clearly see from the pictures you have posted that they are different designs. Both have advantages over the others. I will let you delve into it a bit more.

Haven't you noticed that my quotation is specifically on Ka-50 case, with references to fixed wings only for theoretical basis purposes? And 2-engine ficed wing? Please, let's keep it simple and heli-only (at least in the conclusions department).

I do understand that you are referring to the KA-50. However Slug mentioned Asymetric lift and i gave an example of asymetric lift. The same principles apply to rotor as fixed wing in forward flight and hence i used that example to show that you can fly in balance even with asymetric lift.

I have no problem with the publications from the FAA that you have posted. I was (and probably being a little finicky) pointing out some misgivings in the way you portrayed that info. Maybe it was the way i read your post perhaps ???

 

If you have found some incorrect bit in it, please rephrase and highlight what you don't agree with exactly.

 

Ok i have read and re-read this part of your post trying to think of all permeatations towards interpretation that i may have missed your meaning.

If you are referring to how turn co-ordinators work then.....

Flight characteristics will change with respect to pitch and power datums as well as speed changes. For a change in any of these you will need a different input on the controls to maintain balanced flight.

A turn co-ordinator will advise you of the INPUTS NEEDED to gain co-ordinated flight level and in the turn.

However, if you are referring solely to the the KA-50, then it does not have either a TURN CO-ORDINATOR or TURN INDICATOR so i therefore don't understand why we are mentioning it.

Are we discussing how an Turn co-ordinator or indiciator works, or are we talking about the the ADI with slip ball? (though you can work out a co-ordinated turn approx with a bit of mental calc using the ADI and slip ball).

Seeing you askin questions about Ka-50's flying qualities makes me wonder are you even experienced enough with the Ka-50 to be discussing the specifically heli part of my posts. I don't mean to look down upon you (as I have few flight hours on my account either).

I have no problem with you trying to talk down on me. But at what area are you referring to. My knowledge of the black shark that i have utilised since its release or my real life knowledge (professional pilot)?

You have not understood the point i was trying to make with my food for thought questions.

The ball IS a flawed instrument. You can only argue how much flawed (obviously more falwed for the application on helicopters). What you fail to understand is the solid logic that a statement 'ball is flawed' does not imply 'ball is useless' and certainly it does not imply 'ball is equally useless everywhere'.

I totally understand what you have writen, however you do not understand the ball fully. It is not a flawed instrument. It is a callibrated instrument that will show deviations in the flight regimes outside of "balanced flight". If it is not central, you are either

1. Not level in flight

2. Skidding

3. Slipping.

This is what it does, it works perfectly. If you choose to fly with the ball not centered, fine, it is telling you that the aicraft is performing one or more of the 3 items above. This does not make it flawed, this makes it useful.

Lets face it, a helicopter does what a fixed wing can't. It can move sideways, vertically and backwards. Any compbination of these to the smallest extreme will deviate the ball from centre.

Like i said, there if no TURN CO-ORDINATOR or TURN INDICATOR (either of the two instruments in the picture you provided in your previousl post) in the ka-50 so i am unsure why you have referenced it in you post at all.

Unless i am a twit and missed this instrument in the cockpit.

Sure it can. It can maintain level attitude. It can also fly coordinated. It can even fly in a straight line.

 

The big assumption here is that it can do all 3 at once.

Hmm, you're right. The Shark can fly coordinated and wings level, it's just that in doing so it'll be flying a circular loop rather than a straight line.

However Slug mentioned Asymetric lift and i gave an example of asymetric lift. The same principles apply to rotor as fixed wing in forward flight and hence i used that example to show that you can fly in balance even with asymetric lift.

You're right, my statement was too vague. The Ka-50 not only has asymmetric lift, but the asymmetry is coupled to its yaw moment, which makes it much it different than traditional fixed wing A/C.

I totally understand what you have writen, however you do not understand the ball fully. It is not a flawed instrument. It is a callibrated instrument that will show deviations in the flight regimes outside of "balanced flight". If it is not central, you are either

 

1. Not level in flight

2. Skidding

3. Slipping.

 

This is what it does, it works perfectly.

I think we can all agree with the above. Where our opinions seem to differ is, the Ka-50 isn't capable of flying without doing one of the above. And as such, flying "coordinated" in a Ka-50 means picking one of the above three in order to minimize the other two, whereas in a fixed wing aircraft you fly coordinated by minimizing all three.

Where our opinions seem to differ is, the Ka-50 isn't capable of flying without doing one of the above. And as such, flying "coordinated" in a Ka-50 means picking one of the above three in order to minimize the other two, whereas in a fixed wing aircraft you fly coordinated by minimizing all three.

I am not at any point debating whether the KA-50 can do that or not. I am just referring to inferences towards what a turn-co-ordinator, turn indicator and balance ball are, what they are used for and how useful they are. Also i am wondering why these are being referenced as the KA-50 does not have either aside from balance ball

Sorry, but I'm not going to respond to essays as they are not needed here. As far as I'm concerned we can continue the discussion starting from what was incorrect in my long quotation with pictures.

Well, considering that humans are crooked, not symmetrical and will walk in circles if blind folded cause one leg is shorter than the other, are imperfect making mistakes all the time, using imperfect materials to make components for the KA50 that was designed by imperfect people and then are using an imperfect person to assemble the flawed, imperfect parts into a complete helicopter.

Then an imperfect pilot gets in and reads an imperfect gauge and trys to fly a perfectly straight line or make a perfect turn:lol::lol::lol:

That's just too rich, heck they are lucky the thing even gets off the ground without coming apart:megalol::megalol::megalol:

If you want to get pedantic (and who doesn't around the Holidays), the turn coordinator and the turn indicator are both indicators in the sense they are indicating instruments. It's what they are indicating that differs. One indicates yaw angular velocity while the other indicates combined yaw and roll angular velocity.

The yaw-only gyro instrument is known as the "turn indicator."

The lateral accelerometer is known as the "inclinometer."

If combined into one instrument together they are known as the "turn and slip indicator."

The term "turn coordinator" is the name for the combined instrument consisting of both a turn indicator and the inclinometer where the turn indicator has some bank rate coupling to its gyro.

There is no common name for for the coupled-axis turn indicator without an inclinometer.

As far as I can figure the coupled-axis nature of the turn indicator's gryo is simply to make the instrument more responsive and "ADI-like" to bank inputs when starting and stopping a turn for the pilot's benefit. The angle is probably chosen such that the bank sensing tendency reaches the standard rate mark just as that amount of bank which (when coordinated) results in a standard rate level turn.

The goof is in calling the inclinometer a "slip indicator" since it doesn't necessarily show slip. That's an approximation of what it can show in most fixed-wing aircraft. It's an accelerometer and all it does is show you acceleration and in only one dimension at that. You could be flying sideways at right angles while doing loops but as long as you weren't accelerating laterally the ball would be centered.

==========

The nutty thing about the off-the-shelf inclinometer is that it's marked with the assumption that straight, non-slipped flight is done with the ball centered. It took me a lot of head pounding to wrap my brain around the idea that this assumption isn't always true when it comes to the Ka-50 or any helicopter.

It took a lot of looking but this is by far the best description of what's been going on I've seen: http://www.verticalmag.com/control/news/templates/?z=0&a=14170

@ Frederf,

You have got the basic idea.

However, let me define the two.

A turn indicator will show rate of turn however this needs to be established at a given tas and given angle of bank. Usually requiring the use of more than one instrument to perform the task. Away from the set datums of TAS and angle of bank the turn indicator will not correctly show rate of turn.

A turn co-ordinator will show you a rate one trun at any given TAS and you can use this instrument solely to perform the task.

I am not sure of you term inclinometer and no where through my studies has the term inclinometer been used. Basically the turn co-ordinator has its gimbal raised at the front by 30 degrees which through precession will make it sensitive to roll and yaw.

@ Bucic

So as i said, they are two different instrument that can show the same information. However, they perform differently, are different and that is why they are not the same.

To call them both indicators, well yes, we can in the loose sense of the word call them indicators. Just like i can call an FMS an indicator as it will indicate various parameters of the aircraft for me (if correctly set).

 

Sorry, but I'm not going to respond to essays as they are not needed here. As far as I'm concerned we can continue the discussion starting from what was incorrect in my long quotation with pictures.

I am not after a response from you. However i have replied to the innacuracies you have portrayed. The information you have copied and pasted is correct. The way you described it is not. For the benefit of people who do not know better, i thought it would be good to let them know.

In any event and the main point that sparked my discussion is....

The KA-50 does not have either a turn co-ordinator nor a turn indicator where you said it does.

I have also clarified the differences between a turn co-ordinator and a turn indicator which you seemed to not know.

I have also explained that the balance ball is not a flawed instrument and is quite useful.

-----------

Just as an addendum, as it was late last night. I mentioned that the KA-50 only has an ADI with slip ball..... That should read AHI with slip ball.

Jazer, I didn't record a track for you yesterday. Please use one of the tracks shipped with BS, in the Demos folder, Area Defense. Other tracks from that folder are good too. You can also use one of the tracks posted here (not by me) http://forums.eagle.ru/showthread.php?t=58145&page=2

When you play them, one thing you should do at one point would be to zoom in on the hud, so that you can clearly see the vain sensors and how they behave during turns. For high speed forward flight prefer to fly with slight bank angle but no sideslip.

Let me know how it went and post a track of you doing some S-es and high speed level flight.

alright, I will post a track, but sometime next week, I won't be able to post anything this week.

Just for confirmation Jazjar,

You can fly wings level, and have the balance ball centered.

I have done some indepth testing and as follows.

In "wings" level flight with the ball centred and at speeds tested between 210 and 250 klm/hr the difference between track and heading can be minimuzed to about 6 degrees.

Here are some some videos or helicopters in flight (both different types) with the ball nicely centred.

Volume off for first one.

The second shows the ball remaining centered during light manouvres.

Sorry, but could you post a track of the KA-50 please? Coast Guard pit is sexy, but I want to see the coaxial rotor dynamics.

A turn indicator will show rate of turn however this needs to be established at a given tas and given angle of bank.

False and true in that order. The gyroscopic instrument is not dependent on linear speed at all. It shows the same rate of turn at 300 knots as it does on an oversize turn table on the ground. All motion is relative. There is no such thing as absolute speed. As for bank, that is true because the rate at which the gyroscope is turned in the yaw axis is only the same as the heading change rate when there is no bank. At 45° bank the rate of heading change is 70.7% the yaw rate of the instrument due to the misalignment of these axes.

I am not sure of you term inclinometer and no where through my studies has the term inclinometer been used. Basically the turn co-ordinator has its gimbal raised at the front by 30 degrees which through precession will make it sensitive to roll and yaw.

The term "turn indicator" refers to the gyroscopic instrument only. It is rare to find the gyroscopic portion without the inclinometer, but they do exist. The combination of the gyroscopic instrument plus the inclinometer is termed a "turn and slip indicator." The term "turn coordinator" is the name for the combined canted-gyro turn indicator and an inclinometer.

The KA-50 does not have either a turn co-ordinator nor a turn indicator where you said it does.

This is true. The Ka-50 has neither of these. It has an ADI with an inclinometer.

I have also explained that the balance ball is not a flawed instrument and is quite useful.

The instrument is not flawed but the general assumption of what the instrument shows is not correct. The "slip ball" doesn't necessarily indicate slip. You can be slipping the aircraft and have a centered ball and you can similarly have no slip condition and have the ball not centered.

Just as an addendum, as it was late last night. I mentioned that the KA-50 only has an ADI with slip ball..... That should read AHI with slip ball.

The line between ADI and AH are semi-hazy but I believe the fact that the instrument receives INS information exterior to itself places it squarely in the ADI category.

False and true in that order. The gyroscopic instrument is not dependent on linear speed at all. It shows the same rate of turn at 300 knots as it does on an oversize turn table on the ground. All motion is relative. There is no such thing as absolute speed. As for bank, that is true because the rate at which the gyroscope is turned in the yaw axis is only the same as the heading change rate when there is no bank. At 45° bank the rate of heading change is 70.7% the yaw rate of the instrument due to the misalignment of these axes.

 

I am sorry frederf, i think you have misread some of my post and possibly not understand what is meant by a rated turn.

A rated turn is also referenced as a rate 1, 2 or 3 turns, most notably rate one turns as they are most common.

A rate 1 turn will show show a change of 3 degrees per second. Therefore a rate 1 turn will take 2 minutes for 360 degrees and 1 minute for 180 degrees, no matter what speed you are going. This is what is defined by a rated turn.

For simplicity i will use definition of rate 1 turns now to avoid further confusion.

Forward velocity will have an impact on the bank angle needed to attain a rate 1 turn. That is why my previous statement was 100% correct.

Just to prove to you that I was correct, i will qoute directly from commercial pilot study material.

Listed under errors for turn indicators

"...the indicators are calibrated to show rates of turn correctly in balanced turns for Rate 1, 2 and 3 turns at specific angles of bank and TAS. Although the indicated rate of turn will be incorrect at speeds away from these datums..."

The term "turn indicator" refers to the gyroscopic instrument only. It is rare to find the gyroscopic portion without the inclinometer, but they do exist. The combination of the gyroscopic instrument plus the inclinometer is termed a "turn and slip indicator." The term "turn coordinator" is the name for the combined canted-gyro turn indicator and an inclinometer.

 

Nowhere in the JAR ATPL theory is the term inclinometer used (well not when i studied for it anyway). however, through a little research, i now know you are referencing the slip ball. If you obtained the term inclinometer from wikipedia then you should not be referencing this material for aeronatuical purposes. For one wikipedia mentions "inclinometer-like".

Just to prove a point with wikipedia. Even though it says the author has used FAA material for his article, it has a picture of a turn co-ordinator but it is listed as a turn indicator. However, on the instrument it clearly says turn co-ordinator. LOL Ohh dear. The two instuments are not the same.

For simplicity and as the european commercial text does not refer to inclinometers, i will make reference solely to slip ball.

Aside from my mis-interpretation of the term inclinometer, what is the point of the above qoute?

The line between ADI and AH are semi-hazy but I believe the fact that the instrument receives INS information exterior to itself places it squarely in the ADI category.

You are correct, I agree on this.