Corner Velocity for AH planes

[Furious]

Maybe the its not the pilot dying, but catostophic damage to the airframe.



F.

[Innominate]

Originally posted by Furious
Maybe the its not the pilot dying, but catostophic damage to the airframe.
F.

The screen flashes red, the same as when the pilot dies from a pilot wound.

[Widewing]

Originally posted by Furious
Maybe the its not the pilot dying, but catostophic damage to the airframe.



F.

No damage to the airframe is evident. Moreover, the levels and duration of input are far below that required to exceed the modulus of elasticity of any metal employed in aircraft construction. Structures require time to fail, especially when the level of force is only marginally greater than the rated limit for sustain loading. Time is a key component in the force equation.

We are seeing instant failures, not of the airplane, but of the far more compliant human.

It's a strange bug....

My regards,

Widewing

[phaetn]

Innominatem you are quite correct.  True corner speed is the lowest velocity at which max Gs can be held.

For the uninitiated, there are two things to be considered when considering corner speed: velocity and G load.  

Naturally, the slower the velocity, the harder it is to maintain high Gs, and the smaller the radius of a turn.  While carving a tight turn sounds good, what's actually more important in aerial combat than the turn radius is the rate of turn (measured in degrees per second) and is the rate at which the nose changes heading.  This is vital since it determines how quickly the forward aspect can be brought to bear on a target, and smaller radius turns by the enemy can be countered by such techniques as offset circles, high and low yo-yos, etc.  Being able to get the nose around faster is definitely a big advantage over carving a smaller circle.

True corner speed is the point at which an aircraft achieves its highest rate of turn in dps.  This is the lowest speed at which maximum Gs can be attained, and results in the highest instantaneous turn rate.  It is very pilot dependent, and any speed above that is effectively "wasted" in so far as turn rate is concerned (since it is effectively G limited).

This true corner speed will definitely vary from plane to plane.  To say that everyone blacks out at 6Gs in AH is not the same as to ascertain what the lowest velocity is in a given plane at which one blacks out.

Of course, energy is bled very quickly when holding max Gs, and as this load can no longer be held, then the turn rate decays (and the radius of the turn will also decrease).   This bring up a second important figure, sustained  corner speed.

This is the highest speed that can be maintained while holding the highest constant G load -- and results in a constant rate of turn that can effectively be held indefinitely.   This is important when a fight degenerates into a spiralling circle fight.  Again, this will vary from plane to plane.

One of the reasons that energy management is critical in a dogfight [thinking T&B here, not boom&zoom] is that one wants to be as close as possible to true corner speed (instantateous turn rate) as often as possible, knowing that it can only be approached momentarily, but never held.  It is a constant struggle trying to achieve it.  It may require losing speed in a high energy situation, while much more often than not it's about exceeding sustained corner velocity to try and get as close as one can to the true corner speed.

Energy management has other vital concerns, too, like trading velocity for alt and vice versa, but that's another matter.

Cheers,
phaetn

[Elysian]

Originally posted by hitech
Pilot G limits do not effect pulling g's on the plane, you just black out more.

Pilot g's do not kill the pilot.

Btw Connering speed should be IAS not TAS.


HiTech

Oops, that's right, I meant IAS.

[LoneStarBuckeye]

I posted a while ago, wondering whether planes were limited to pulling the g-load (i.e., centripetal acceleration) that caused the pilot to black out (6 g, I think).  I had been flying as if they were, and had found myself losing angles on merges without understanding why.  

As Lephturn pointed out in that thread, an easy way to convince yourself that AH's planes are not articially limited to generating 6g of centripetal acceleration is to go offline and take a P-51 (or any other plane) up to a comfortable height.  Dive until you reach terminal velocity and abruptly pull full back on your stick.  You will black out, of course, but you will also likely rip the wings off the plane, due to the high (i.e., more than 6g) g-load you forced the plane to generate and endure.  (If you watch the g-meter closely, you can see the needle swing past 6-g before you black out.  I think that the black-out effect is not instanteous, but it is pretty quick.)  In contrast, when you enter a horizontal 6g blackout turn at 300 IAS in a P-51, you won't rip the wings off the plane.  

It is worth noting that if you pull too hard for too long in the blackout region (i.e., the region above the 6g line in a "doghouse plot") of the flight envelope, you will experience some sort of "blackout lock" that persists for a while after you unload.

Badboy has some very nice doghouse plots (i.e., "energy maneuverability diagrams") for various AH planes (e.g., Spit V, Spit IX, P-51D, F6F) in an article he has published at http://www.simhq.com/simhq3/sims/air_combat/energymgmt/.  If I recall correctly, his plots all assume the following parameters:  sea level, 25% fuel, full military power.  (I suspect that the plots would be more or less accurate at different altitudes if IAS is used to measure velocity.)  In these plots, the "corner" velocity is readily apparent, as it lies at the intersection (corner) of the 6g and stall curves.  The plots also include the useful "sustained turn" line (Ps=0 curve?), which relates the maximum g one can pull at various speeds without losing energy.  Fly below that curve (i.e., pull a smaller g-load) and you gain energy; fly above it (i.e., pull a higher g-load) and you lose energy.

It would be nice to see plots like this for the entire AH plane set, but I imagine it would be a real chore to put them all together.  It would take a much steadier hand and a much clearer eye than mine to garner the needed data by testing the planes offline.  If we had precise digital readouts (for offline use) of IAS and g-load,  it would be much easier.  I just can't read the gauges well enough (particularly at the onset of blackout) to get the needed information.  

- JNOV