F-16C, F-16E vs F-14D

[magnum4469]

Years ago flying the "A" blk 15 against F-14D doing BFM and ACM sorties. We were flying with centerline and 2 bag jets, the F-14s were clean. In fights with the 2 bag jets it was about an even match with slight advantage to F-14s. Centerline jets had huge advantage vs F-14. Clean vs clean jets the F-14 would be no match for the F-16. You can't just compare the turn rate you also have to look at the radius. The setups were all standard, 20k, 350kts, line abreast 1.5nm split, check away 30 degrees, at approx 2nm separation turn in and fights on. Meet 180 degrees out, the F-14 would go into horizontal break two circle turn, Vipers would pull vertical and roll and pull to 6 oclock. Employing either AIM-9 or gun. The F-14 provided a huge target compared to Viper for putting the pipper on. The tail stab of the F-14 (33' wide, compared to 32' wide of the F-16 wing) had almost the same area as the entire wing of the Viper. As soon as you saw the wings sweeping forward you knew he was out of energy and went in for the gun shot. Not to take anything away from the F-14, it was a great platform for what it was designed for, keeping Bear bombers away from carrier air group and shooting down cruise missiles but as far as a knife fighting dog fighter it came up short, even with the "D" model upgrades.

[tailgate]

I think someone once told or I read maybe, that getting "low' or "slow" or both in ACM was a sure fire way to end up on someone's sill as a kill marking.......

[F-16ADF]

I just spoke with an F-22 Raptor pilot who prior flew all the GE powered Vipers. And as he put it, 'the big mouth Block 30 is the best BFM jet of that group (Block 30,40,50).'

So this initial comparison, from other site, is rendered superfluous and incorrect.

[garrya]

I was curious about F-14 lift curve relative to its wing sweep and its ITR performance so i decided to ask Spurt about that,





i found his reply very informative so i put it here as well

[madrat]

So without some evolution, like Su-27 gaining a canard to become Su-30, the F-14 design was basically maxxed out for WVR combat. And with its big RCS, you had the nail in the coffin.

[F-16ADF]

Garrya and Spurts,

Here is the F-14B, 35k chart with maneuvering devices on auto:


http://imgur.com/a/UcFmW

[F-16ADF]

After .8 Mach, everything basically goes down the toilet.

[F-16ADF]

A good comparison on the ability of the "lifting body" of the F-14 is to compare the Mirage 2000 15K chart (remember to include 6AAM vs 2AAM loadout) against the 15K Tomcat chart. Even with 6AAM, the Mirage 2000 still has a superior ITR, smaller turn radius.

[madrat]

In all fairness, fighting at such high speeds in a turning fight wasn't real ideal until WVA and LOAL became possible. Honestly, the most likely opponents for F-14D were not exactly modern.

[sprstdlyscottsmn]

f-16adf, thanks for the chart. It confirms my calculations well.

These are the sheets garrya sent me and the data lines I used in them.

The following picture is the "raw data" I pulled from the sheets garrya sent me.

CL data 1.JPG (35.97 KiB) Viewed 7646 times

I included the formula I used to calculate CL and all the variable data. When I started pulling data from the charts I did not know the results. I then wanted to plot the CLmax against wing sweep and Mach. The Mach is more telling of the two, honestly, because you can see the sweep effects and pressure change effects combined more easily. I then took these CLmax values and plotted ITR to 6.5G using the (G^2-1)^.5 method to account for needing to not lose altitude and to be consistent with my F-16 and F-15 data.

The F-16 has a reducing AoAmax and thus a reducing CLmax as speed increases from the CAT-I limiter. The FBW control system has lots of tricks to keep the center of pressure in the right place. In full disclosure, the F-15 data is under the assumption that it can hit its max CL of 1.64 (which occurs at ~40 aoa) all the way up to 9G. I then corrected the Gmax for the OWS which did not have an impact until over 1.1M. As an FYI, the "Stall Speeds" chart in the F-15-1 gives a much lower CLmax than the "Lift Limit" lines in the flight envelope diagram. I make the assumption that the "stall speed" charts use ~20 AoA as the stall limit. The text of the -1, as well as the DCS flight model, both indicate that stalling begins well before maximum AoA.

AoA 1.1.JPG (23.05 KiB) Viewed 7646 times

AoA 1.2.JPG (29.19 KiB) Viewed 7646 times

AoA 2.JPG (27.23 KiB) Viewed 7646 times

Before Garrya brought this up I assumed CLmax was constant on the F-14. Flight test data tells me otherwise. For performance modeling purposes I can modify my F-16 CAT-I system to give a similar end result, or I can just get to work on my more complex spreadsheet I have been kicking around.

[eloise]

You are one of the most knowledgeable about aerodynamic in here. But I think there could be a mistake in your estimate. F-14 in your diagram only has ITR = 5.8 at Mach 0.5, equal to F-16?. But in the 10k ft EM diagram from garryA in page1, F-14 ITR at Mach 0.5 is much better than F-16 (23 deg/sec vs 17 deg/sec) . What close the gap at 35k ft?

[sprstdlyscottsmn]

F-14 in your diagram only has ITR = 5.8 at Mach 0.5, equal to F-16?. But in the 10k ft EM diagram from garryA in page1, F-14 ITR at Mach 0.5 is much better than F-16 (23 deg/sec vs 17 deg/sec) . What close the gap at 35k ft?

The F-16 is always under the effects of the CAT-I limiter for A-A loads. Look at the chart f-16adf posted for 35kft with that same F-14D. It looks like my chart. The sweep system being different at higher altitude may be to blame. Maybe the high AR wing of the Tomcat is less effective at higher altitudes? It can, however, be empirically seen even within the official F-14D charts that at 35kft the Tomcat has poor turning ability with a decreasing Clmax as speed increases.

[F-16ADF]

Everything that the Block 50 is doing as far as turning is happening at a higher speed than the lighter Vipers. That was confirmed by some of Gums posts from years back. And even the F-22 pilot whom I spoke with yesterday attested to that. The Block 50 is around 1400lbs heavier than the Block 30, and generally 3300-3800lbs heavier than the A models, notably the early small tails.


Block 30 with MCID aka Big Mouth:

http://imgur.com/a/XKW5c


Block 50:

http://imgur.com/a/ARjoV




Since everyone has the HAF supplement, compare the Block 50/52 at 5K CLEAN vs the -220 Block 15 at 5K with 2 AAM and half internal fuel.



Now I really don't know the validity of this chart (I do not have the USAF T.O. Block 15 -1-1). However, if you do the comparison (a -220 Block 15 vs a Clean Block 50/52 all at 5K) you will see that even though the Block 15 has a weaker engine and it has more internal fuel + 2 Aim-9's; it has basically a smaller turn radius and better ITR than either or them and is hardly behind in STR. And if you were going to equalize the charts (Block 50/52 with 2 Aim-9 + 1/2 internal fuel) their numbers get even worse against a similarly equipped light A model. And some F-16A guys have said that it has a "lighter nose" than the heavier C models.


Block 15 F-16A at 5K (1/2 internal fuel + 2Aim-9):
http://imgur.com/a/bVSUI

Block 52 F-16C at 5K CLEAN:
http://imgur.com/a/4cZJT

Block 50 F-16C at 5K CLEAN:
http://imgur.com/a/7BMnt


So even though the Block 50/52 have tons of power, that power doesn't always translate into better performance metrics; Because they also gained a significant amount of weight that many people generally seem to forget. If someone actually has the USAF T.O. -1-1 for the Block 10/15 please post the 5K Clean chart (if my calculations are in error).

The small tail Block 10 and the MCID Block 30 seem to be the best at BFM (with maybe the latter having a slight edge).



So once again, why would you want to compare the best fighter version of the Tomcat (in this case the B) against the heavier Block 50 which is NOT the best BFM version of the F-16? It is just a nonsensical, illogical juxtaposition.

[garrya]

Everything that the Block 50 is doing as far as turning is happening at a higher speed than the lighter Vipers. That was confirmed by some of Gums posts from years back. And even the F-22 pilot whom I spoke with yesterday attested to that. The Block 50 is around 1400lbs heavier than the Block 30, and generally 3300-3800lbs heavier than the A models, notably the early small tails.
Block 30 with MCID aka Big Mouth:

Block 50:

From what i heard block 30 has always been the best F-16 for dogfight according to pilot.

[garrya]

In full disclosure, the F-15 data is under the assumption that it can hit its max CL of 1.64 (which occurs at ~40 aoa) all the way up to 9G

It is certainly not my expectation that F-15 turn out to have the best ITR, i have always thought F-14 has the best ITR since F-16 is AoA limited and F-15 doesn't have high lift devices.
Btw, isn't it a bit far fetch to assume F-15 can be at AoA of 40 degrees at 9G?