Help me understand corner speed please

[promitheas]

Ok, so any of the few videos I watch on youtube about corner speed go into some complicated physics equations to explain corner speed, whereas I just need to get the watered down simple version so I can understand it.

 

:helpsmilie:

Q: What exactly is corner speed? (remember, keep it simple)

 

Q: How can I use it effectively regardless of what aircraft I am flying at that moment, in a fight?

 

Thank you very much guys :thumbup:

[Aginor]

Ok, my try at explaining it simple:

 

Corner speed is the minimum speed that still allows you to pull maximum G.

 

So at corner speed you have your maximum turn rate. That's why it is so important.

 

EDIT:

So if you know the corner speed of your aircraft, you know you can pull max Gs and turn at your best rate, without buffeting.

EDIT2:

I think it is somewhere around 400 knots in the F-15C, but don't quote me on that. Depends on altitude also.

 

EDIT3:

Just remembered there was a rather cool publication that explains all that stuff quite understandable:

http://navyflightmanuals.tpub.com/P-821/Corner-Speed-200.htm

Edited August 1, 2016 by Aginor

[promitheas]

Ok, my try at explaining it simple:

 

Corner speed is the minimum speed that still allows you to pull maximum G.

 

So at corner speed you have your maximum turn rate. That's why it is so important.

 

EDIT:

So if you know the corner speed of your aircraft, you know you can pull max Gs and turn at your best rate, without buffeting.

EDIT2:

I think it is somewhere around 400 knots in the F-15C, but don't quote me on that. Depends on altitude also.

 

EDIT3:

Just remembered there was a rather cool publication that explains all that stuff quite understandable:

http://navyflightmanuals.tpub.com/P-821/Corner-Speed-200.htm

 

Thats it. I undestood it with your first line. Min speed while maintaining max G. So now, is there a magic chart or something that give me corner speeds, or corner speed range of different aircraft? Where can I find out corner speed for a plane I want to fly?

 

Thanks!

 

Edit 1: Here is a link to a chart for sustained turn rate of some US Navy aircraft:

http://www.rdrop.com/users/hoofj/corner.htm

Anyone know of anything like this for russian planes?

Edited August 1, 2016 by promitheas

[Aginor]

Well, just to make sure we are on the same page here: Flying at corner speed won't win the fight for you. It is just one of several interesting numbers that can tell you about your possible performance (and that of your enemy).

 

That being said: If you want to know the corner speed the best approach may be just googling your plane's name and the word "corner speed". It is likely that was discussed here and on other forums already.

IIRC the MiG-29 with a few R-73 and fuel has a corner speed around 700km/h, which is slower than the F-15C's. The Su-27 probably has the lowest one, but I don't know it.

[promitheas]

Yeah, google let me down unfortunately xD I couldn't find it anywhere. Also, I know corner speed won't make me the king kong of the air, but in a fight it could end up helping if I use it effectively

[Bushmanni]

Important note: Corner speed gives you the best instantaneous turn rate. The best sustained turn rate usually occurs at different speed (higher than corner speed for fighter jets). EM chart is the usual source for corner speed and best sustained turn speed. These speeds also depend on your weight so there's no magical single speed that fits all scenarios.

 

Besides performance related optimum speed being weight dependent, the turn rate curve where you find that speed might indicate that the optimum speed might not be optimal for your tactical needs. For example you might get lots of extra degrees by starting slightly faster than corner speed without serious drawbacks (depends on the plane). Or you might notice that you get almost optimum sustained turning performance in a larger speed zone so overly optimizing you speed isn't worth the effort (depends on the plane).

 

Unfortunately there's no simple answer for the OPs second question as all simple answers would be invalid and useless. The practical answer is to learn few optimums speeds for different typical scenarios and then interpolate in your head for the situations in between.

 

The use of optimum speeds comes down to two types of BFM flows, nose-to-nose and nose-to-tail. When both fighters turn in the same direction you have nose-to-tail flow where turn rate is important (sustained turn speed more specifically as you need to pull a long turn). When fighters turn in opposite directions you have nose-to-nose flow where turn radius is important (generally achieved by starting with max performance turn and slowing down to minimum radius speed which is typically relatively close to minimum level flight speed).

 

You want to optimize your flying speed for each flow to get more performance out of your planer than the bandit. Getting into the bandits six is all down to your management of the flow geometry and getting more flow relevant performance out of your plane than the bandit. Often you need to anticipate the change in flow (initiated by the bandit or you) to get a jump start to beat the bandit. When you throw in energy management you also need to understand optimum speeds for vertical maneuvers and climbing.

 

BVR fights can take a long time and your fuel is usually just as important as your missiles for staying relevant for the fight. So in BVR you also need to consider fuel economy and different climb profiles for attaining altitude, range, speed or energy in efficient or quick fashion. These profiles are also weight and drag dependent. If you look in a real flight manual of a fighter plane you will see it's filled with performance charts and they are there for a reason. Fortunately you don't need to memorize all of them for combat but you need to look through them and figure out some rules of thumb for your own use.

 

You can make your own EM charts if you learn lua scripting and some elementary physics required to do the calculations for extracting the turn performance data from flight test. Besides that your options are real world data from the internet or someone doing the flight test for you.

[promitheas]

Ok, that helps

[AJaromir]

Officially the corner speed is the speed when you have the fastest angular speed in turn. (deg/s)

It's very important for close combat in every plane, WWII planes included.

 

BTW: here is very good video from Falcon 3.0 about air combat:

Edited August 3, 2016 by AJaromir

[Bushmanni]

Officially the corner speed is the speed when you have the fastest angular speed in turn. (deg/s)

 

I'd like to see the official documentation describing it like that.

[Sryan]

You can find EM or Energy-Maneuverability diagrams online for many different aircraft online

 

 

In case you can't read these diagrams. There's a great step by step guide to read these over on simHQ. http://www.simhq.com/_air/air_011a.html

 

Remember that the diagrams are usually only valid for a certain loadout, fuel quantity and altitude. But they're good at giving you a general idea.