Forum: F-16 versus XYZ

Can a jock jump in and explain what happens when in an engagement, the F-16 executes a nine "G" turn and you're down to 200knts? So we've turned into our opponent and may or may not have a shot. Trade potential for kinetic to get back up to velocity? Most engagements occur at a velocity below 300knts, are we still in good standing?

Fuel state, bugging out, all a consideration?

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Standard answer: it depends. If I were at 200Kts and didn't want to be there I would trade altitude and use the AB to get my energy back. If no altitude available (on the deck) then ease off the "G" and let the airspeed build.

What airspeed you want to be at during an engagement depends on what you want to do. 1 v 1, 300 kts and below is not where you want to be unless you are a) defensive and trying to create a closure problem or b) offensive and in a position to employ the gun (or missile).

Generally be between 330 and 380 whenever you can for smallest radius and best turn rate. Faster than that is for closing on the enemy or separating from the enemy. Slower is for a) & b) above.

One thing the USN's Ault Report by Cmd. Frank Ault and the USAF's Red Baron Report showed is that 80% of all dogfights in history have taken place between the altitudes of 15,000 feet and 30,000 feet and speeds of 250mph to 450mph, this is where the F-16 was designed to accel.
If the F-16 is facing a MiG.-29 or F/A-18, the F-16 should not allow its speed to fall below 325mph to 350mph. These two opposing aircraft have their best chance to defeat the F-16 below this speed range. They both have better control at high AoA at low speeds than the F-16.

Adrian

The problem there is convincing the other guy not to get slow. Otherwise you'll just soak up a missile as well

is that opinion based off of experience or just what you've heard?

The F-16s corner velocity (speed at which it turns best) is 450knts.

Dropping the nose and lighting the afterburner is not a good idea. Duke Cunningham and his RIO were about to get a free vacation in the Hanoi Hilton until the infamous "Col Tomb" made this mistake. Makes for an easy shot with a sidewinder.

Elite 1K Joined: Aug 19, 2004 - 09:19 AM Posts: 1092

FDiron wrote:

The F-16s corner velocity (speed at which it turns best) is 450knts.

Dropping the nose and lighting the afterburner is not a good idea. Duke Cunningham and his RIO were about to get a free vacation in the Hanoi Hilton until the infamous "Col Tomb" made this mistake. Makes for an easy shot with a sidewinder.

The F-16 has a "corner plateau" due to its blended AoA/G command system. That being said, the F-16's "corner velocity" is not constant with altitude and I don't think it's ever 450 KCAS (or almost never that high). It comes close at some altitudes near the right edge of the plateau, but to say that 450 KCAS is the F-16's corner velocity is not correct. At higher altitudes Vc for an F-16 might be as low as 300 KCAS. The idea of the corner plateau, however, really makes speaking of a single Vc misleading. There is usually a range of airspeeds that give nearly equal turn rate for ag iven altitude.

As for regaining energy, lowering the nose and lighting the afterburner and dropping flares while jinking about in the dive might sometimes be preferable to staying slow and close to a bandit engaged offensive on you. If you end up having to do that though, it's usually due to a mistake earlier on in the fight.

dropping the nose in burner isnt bad if you are denying a wez, if you are in a wez...then sucks to be you

From Pete Bonanni's book "Art of the Kill"

"For every fighter, there is an optimum airspeed for achieving the highest turn rate. There airspeed where the jet has the quickest turn rate with the smallest turn radius is called corner velocity. In most modern fighters, it is between 400 and 500 kcas. The F-16 has a corner velocity of about 450 kcas"

KCAS- knots, computed airspeed.

Bonanni was an instructor on the F-16.

Elite 1K Joined: Aug 19, 2004 - 09:19 AM Posts: 1092

Sorry, but he's simplifying things for the reader. Ask any F-16 driver here to look at his EM diagrams in his -1-1 and tell you whether or not they see "quickest turn" marked at a Mach number equivalent to 450 knots. Under most cirumstances, it will be significantly lower than 450 KCAS. I don't need to argue with anyone on this point though. Just go ask the resident F-16 pilots here whether or not Vc for their (or any other) F-16 is 450 KCAS.

Also, what I said about Vc not being constant with altitude still applies. A book like Art of the Kill is not a substitute for actual performance data. You have to dumb things down a bit to appeal to a wide audience such as the combat sim virtual pilots this book was aimed at. Not everyone wants to go through a textbook-like course on the F-16's flight performance. Perhaps you'd also like to check out the F-16 Multi-Command Handbook Volume 5. It talks about the corner plateau. That is official F-16 documentation there. Art of the Kill is not, despite its reputable author.

Raptor One is right, F-16 "corner plateau" is lower than 450. And KCAS is CALIBRATED airspeed

Elite 1K Joined: Aug 19, 2004 - 09:19 AM Posts: 1092

mach2 wrote:

Raptor One is right, F-16 "corner plateau" is lower than 450. And KCAS is CALIBRATED airspeed

Yeah... and just so no one gets more confused, even the -1 manuals will go between KCAS and KIAS (which are basically the same thing). Calibrated airspeed is just indicated airspeed corrected for installation errors due to placement of pitot probes on the aircraft. Another interesting tidbit is that the calculation of KIAS beyond the speed of sound is an iterative process. Smile

I don't think I have seen it mentioned that the only reason for a corner plateau is to decrease the loss of speed as it brings the lines for ITR and STR closer together. Does anyone here know if other AC such as the F/A-18 have a plateau?

Elite 1K Joined: Aug 19, 2004 - 09:19 AM Posts: 1092

Actually, the "reason" for the corner plateau is basically the AoA/G command system which prevents the F-16 from entering a deep stall under almost all circumstances. I've read tons technical reports about this command system and I don't remember ever reading that it was designed to decrease the loss of speed or bring ITR and STR together. Those are just side effects. The F-16 WILL overshoot the limits the command system places on both AoA and G, but usually not enough to enter into an unstable region of flight. The command system was designed to give the jet as much maneuverability as possible while still making it difficult to pitch out of control. This just happens to give you that corner plateau shape we're all refering to. Think of that corner plateau as a way to prevent overshoots that would definitely happen if a higher AoA was reached in those speed ranges.

I understand how the AOA/G limiter works, I have seen the charts. I also applied this information to the performance characteristics and it DRASTICALY lowered the maximum ITR, but resulted in the lowest "Max G" speed loss.

The result is that if, for example, and F/A-18 and an F-16 pass each other at 350 knt and pull into each other for 6 second (arbitrary time frame) the Flacon will have MUCH more speed left than the Hornet. According to my calculations the AOA/G limiter give the Falcon "better decceleration" than even the Eagle.

Of course I do see the benefits of the limiter to avoid avershoot, especially with the G onset rate of the Falcon. Entering a deep stall at 300+ knots would be very... unfortunate. This is likely the reason for the limiter as you said.

I am curious to know if the F-22 has any such limiter as it can fly at 60 degrees angle of attack, that would be a bad scenario for higher speeds. Oh well, I'll find out in about 90 years when they declassify it all.

Forum: F-16 versus XYZ

Energy Depletion/Turns in the F-16