Andraxxus wrote: []Well his work seems thorough and accurate in method, I don't share his assumptions, and accuracy of calculations. Let me put a wall of text and some data to point out his mistakes or areas I don't agree.

F-15

F-15 doesn't have fixed 27% MAC stability, its limited between 22-29,9% and typical CG travel during a mission is as follows;

Its reasonable for any maneuvering is required in mid mission, so I assume CG distance is at 24% MAC, and working from wing area and Mean chord length, it translates to 3,632 feet, not 4.

At landing CG detrimental, so that aircraft will not roll back to its rear end, I assume 10 degree AOA at landing, working from wikipedia 3-view drawing and moving backwards from 22% MAC gives CG to be roughly at the 2/3 of the F-15%'s airbrake. (too lazy to draw it and upload it here)

This means distance from the center of the elevators to CG is 7,63 meters or 25,03 feet.

So for X amount of lift, 0,1451X or counter-lift from elevators is required, so roughly 85% of the lift is used.

F-15 Flight manual gives stall speed at 30000 lbs exactly at 110 knots. Calculating Clmax from these gives us Clmax=1,2028 .

Incedentally, F-15's maneuvering Clmax is given by Soviet booklet is 1,0. My calculation gave (1-0,147)*1,2028 = 1,02; not too bad.

F-16

He explains CAT-I limiter well, but its implacions not. We are looking for maneuvering conditions, not stall, so whatever Clmax he found from CFD is irrelevant. AOA@G limitation is there for structural reasons and will change the REAL Clmax of the maneuving aircraft. For example, we know F-16's turn rate, speed and altitude conditions is from its flight manual. F-16 Clmax for M0.4, M0.5 1,3991, 1,5687 respectively. For 9G at 10000 feet, its 1,1.

As for his CFD work; an F-16 blk50 at 36000lbs DI-0 stalls at exactly M0,2 at MIL thrust (according to flight manual). 78kN MIL thrust, 25 degree stall AOA, stall speed, altitude etc are all sufficent to calculate Clmax, which equates to 1,5827.

So F-16's clmax is ballpark around 1.6 for stall and around 1.3 when maneuvering due to CAT-I and 1.1 at 9G ITR turns. Of course that is if we are talking about subsonic only.

F-35

"I estimate clmax of F-35 to be 1.8" No offense to the author, thats utter nonsense, and clearly not good enough.

Typical 64A204 F-16 uses tops out at clmax = ~1,1. F-16 adds to that primarily with LERX vortices and LE flaps to delay the stall and as a result achieves Clmax = ~1,6

What if an aircraft didn't have LERX and LE flaps? Well F-15 uses very similar but thinner 64A203 airfoil. Despite wide body, and 64A006 wing roots, It barely manages to get around Clmax = 1,2

1.8?? Lets see the ONLY competitive aircraft: Su-27 has LERX, le flaps, and achieves Clmax = 1.85 with this THICK airfoil:

And remember, this airfoil more or less makes up the whole Su-27, from lerx to tail, excluding nacelles. Even area from nose to stinger is shaped as a supercritical airfoil, with nose look slightly downwards to improve lift in the "tunnel". As for F-35, such lifting body design is not present on F-35 to any degree (its more like F-15's body lift than Su-27 with lifting body), has no lerx to make airflow stick to wings, and my mk1 eyeball inspection tells it uses MUCH thinner wings than the profile above. (Abominal extensions below wing roots don't count as wings)

So for F-35, Clmax = 1.4 is most reasonable assumption to me, as its right between F-15 and F-16; with # of aerodynamic features is also 0 for F-15, 1 for F-35, and 2 F-16, i just take the middle: (1,6 + 1,2) / 2. This is also ballpark similar to MiG-29 and F-18, and I assume F-35 wont have AOA limitations of F-16, which is unique to that aircraft. So;

And by that, "CL*A" of these aircraft should be as follows (I am also writing in feet so that you can compare with his)

F-15E = 608*1,2*0,85 = 620 ft2 = 57,6m2

F-16C = 302*1,3 = 423 ft2 = 36,41 m2 and 332 ft2 =30,84m2 @9G

F-35A = 460*1,4 = 644 ft2 = 59,83 m2

With these Cl*A's known, we need weight to judge performance. Lets assume dogfight 500nm out take his range graph as accurate (I am also adding Su-27 as potential adversary, and just because I like Su-27)

F-15E = 58% fuel, = 18000kg

F-16C = 83% fuel. = 11735kg

F-35A = 57% fuel. = 18082kg

Su-27 = 40% fuel. = 20060kg (50% should easily reach

While all can pull 9Gs, their ITR will differ by speed;

F-15E = 17,17 deg/s @ 292 m/s,

F-16C = 16,07 deg/s @ 313 m/s,

F-35A = 17,6 deg/s @ 285 m/s,

Su-27 = 20,96 deg/s @ 240 m/s (Su-27's clmax @M0,75 = 1,51)

For STR we simply have insufficent data. Even we assume same Cd, we have to know exact Lift-drag to even make guesstimates about STR.

Lets go on with some other mistakes:

He is right about ANY payload attached to CFT limits F-15E to M1.4 but, again, his interpretion is wrong. To simplify, F-15E's CFT has 6 stations. Two rows are simply groupped as inboard and outboard in flight manual and these do limit to M1.4.

However, F-15 carries AIM-120s on stations 3C, 4C, 6C and 7C EVEN WITH CFT INSTALLED. (those stations extrude from inside CFT, between CT-1, CT-2 and CT-3 like this:

So they are NOT CFT stations, and still subjected to general CFT limit of M2.0:

As for the rest, he is making assumptions. This is his idea, I don't have a clue if they are correct or not.