F-14 low speed prowess vs Other Aircraft

[Hummingbird]

I can understand what the fuss is all about, but it wouldn't be the first time such a thing happened. If you look at the F-18/C Clmax-Ps=0 relations, you can see another such case. The 4AAM F-18's Ps=0 seams to ride the Clmax from 0 to 180KIAS or mach 0.27 ASL. And accordingly it states over 3g sustained at that point. What method was used to generate it? Is the data 100% accurate? I have no idea, to be honest. But does it matter?

 

It's very simple really, the F-15 won't be able to sustain a higher dps turn at a speed where it can hardly fly as compared to the F-14. It's a physical impossibility.

 

Oh no, you are not getting me into an argument about what is the best ACM platform out there ;)

 

Out there? Too many aircraft to choose from :P

 

No, I was talking about the aircraft we have ingame atm.

[lunaticfringe]

Simply not worth the time.

Edited March 31, 2015 by lunaticfringe

[DGC338]

Why the 30 degree bank line? What account of max thrust v mil power?

Edited March 31, 2015 by DGC338

[Hummingbird]

Here are some hard figures direct from the manuals;

 

Stalling speeds at SL, power off, speed brakes retracted, gear & flaps down:

 

F-14 (50,000 lbs) = 114 kts @ level flight / 122.5 kts @ 30 deg bank / 136 kts @ 45 deg bank / 161 kts @ 60 deg bank

F-15 (39,000 lbs) = 123 kts @ level flight / 132.5 kts @ 30 deg bank / 148 kts @ 45 deg bank / 176 kts @ 60 deg bank

 

Gear & flaps up you can add about 5 kts to those figures, a small number but maneuver flaps & slats are still working when needed, explaining the small difference.

 

Note: The difference becomes greater in favor of the F-14 the greater the bank angle, which I assume is because of the lifting body design beginning to take more effect as the AoA increases.

Edited March 31, 2015 by Hummingbird

[GGTharos]

Try a 35000lbs eagle ... you know, more or less max-landing weight configuration (not that you can't land with anything above that, but above that it's considered 'heavy').

[Pilum]

Here are some hard figures direct from the manuals;

 

Stalling speeds at SL, power off, speed brakes retracted, gear & flaps down:

 

F-14 (50,000 lbs) = 114 kts @ level flight / 122.5 kts @ 30 deg bank / 136 kts @ 45 deg bank / 161 kts @ 60 deg bank

F-15 (39,000 lbs) = 123 kts @ level flight / 132.5 kts @ 30 deg bank / 148 kts @ 45 deg bank / 176 kts @ 60 deg bank

 

Gear & flaps up you can add about 5 kts to those figures, a small number but maneuver flaps & slats are still working when needed, explaining the small difference.

 

Note: The difference becomes greater in favor of the F-14 the greater the bank angle, which I assume is because of the lifting body design beginning to take more effect as the AoA increases.

 

Well I think you should be careful before drawing too firm conclusions about the power on stall characteristics based on these power off figures because adding thrust changes the equation:

 

The power off stall figures will be governed mainly by the amount circulation type lift the wing can produce and in this arena the F-14 can be expected to shine with wing set a moderate sweep. This is also most likely why the F-14 does so well in STR performance in the mid Mach range because the wing can generate a lot of lift utilizing circulation type lift which can be had for a relatively cheap price in terms of drag. At least in comparison to the vortex type lift component added by the strakes on an F-16 or F-18 at higher aoa.

 

So to get a better understanding of how the F-14 and F-15 compare in really slow speed high aoa turning and how well they generate vortex lift, it would be good to see some power on stall numbers instead. This would be especially interesting to see since at such low speeds as M=0.25, i.e. high aoa, vortex lift is an important facilitator and it may well be that the F-15 has an advantage here but without power on data it’s hard to tell. So if someone has access to these numbers this would be really interesting to see.

 

Disclaimer: Note that my interest here is a purely academic and that I’m not advocating that either plane should actively seek out this part of the envelope. :smilewink:

[DGC338]

Simply not worth the time.

 

Is that because you couldn't read the chart correctly?

[Hummingbird]

Try a 35000lbs eagle ... you know, more or less max-landing weight configuration (not that you can't land with anything above that, but above that it's considered 'heavy').

 

Why? I'm not really concerned with landing speeds here, but more with loads expected in combat, and at 39 & 50,000 lbs respectively both aircraft are below their 50% internal fuel load with similar armament.

[GGTharos]

Then why aren't you using a 54000lbs tomcat?

[Hummingbird]

Well I think you should be careful before drawing too firm conclusions about the power on stall characteristics based on these power off figures because adding thrust changes the equation:

 

The power off stall figures will be governed mainly by the amount circulation type lift the wing can produce and in this arena the F-14 can be expected to shine with wing set a moderate sweep. This is also most likely why the F-14 does so well in STR performance in the mid Mach range because the wing can generate a lot of lift utilizing circulation type lift which can be had for a relatively cheap price in terms of drag. At least in comparison to the vortex type lift component added by the strakes on an F-16 or F-18 at higher aoa.

 

So to get a better understanding of how the F-14 and F-15 compare in really slow speed high aoa turning and how well they generate vortex lift, it would be good to see some power on stall numbers instead. This would be especially interesting to see since at such low speeds as M=0.25, i.e. high aoa, vortex lift is an important facilitator and it may well be that the F-15 has an advantage here but without power on data it’s hard to tell. So if someone has access to these numbers this would be really interesting to see.

 

Disclaimer: Note that my interest here is a purely academic and that I’m not advocating that either plane should actively seek out this part of the envelope. :smilewink:

 

Here are the power on stall figures at same weights and configuration (flaps & gear down, speed brakes retracted) for both aircraft at maximum thrust AFB @ Sea Level:

 

F-14D (50,000 lbs) = 95 kts @ level flight / 105 kts @ 30 deg bank / 120 kts @ 45 deg bank / 150 kts @ 60 deg bank

F-15C (39,000 lbs) = 96 kts @ level flight / 107 kts @ 30 deg bank / 124 kts @ 45 deg bank / 156 kts @ 60 deg bank

[Hummingbird]

Then why aren't you using a 54000lbs tomcat?

 

Because I'm not using a 42,000 lbs Eagle either ;)

[lunaticfringe]

Is that because you couldn't read the chart correctly?

 

Not at all. I used the Mil with 30 degrees because its:

 

a. its an averaging of stall (Mil and Power Off, and you'd note the same on the AB chart), and effectively the point of standard wing stall calculation if you run the raw numbers for the F-15.

 

b. The Max Power Chart makes his contention even worse, because it would show the Eagle having almost three G available at 165 knots, but only able to sustain 2 in accordance with the two gauge STR chart.

 

b. I have a wife going into labor (just going through browser windows on my phone now waiting on a final ultrasound, thus I saw this response) so I'll save the time for games with actual children, instead of grown ones. ;)

[GGTharos]

28500lbs + 2800 + 8000 = 39300

 

41800lbs + 2800 + 8000 = 52600

 

We can ignore the weights of the pylons on both aircraft and hope they work out to be close enough - the caveat is that this will affect the fuel quantity.

 

Your 'representative' loadout has the cat sitting at joker or bingo fuel, since he'll be well under 6000lbs. If he uses his afterburner, he might not be going home ... so you've just restricted most of your turning to MIL only. Or maybe he's right next to the carrier, in which case, why not take the flip side with an F-15 next to its airfield at 35000lbs and the cat at 54000?

 

In the end, it's all academic because you don't really know what's being brought to the merge at the time of the fight. Pilots do study the charts but that's just an input to do informed BFM, it's not how you win a fight.

 

Because I'm not using a 42,000 lbs Eagle either ;)

Edited March 31, 2015 by GGTharos

[Allesmor Obranna]

An F-14B (GE F110 engine) demo with full AB takeoff. Rare, because, normally, they ignited it after the take off.

 

[DGC338]

I was just curious to why you deleted the post that had calculations if indeed they are correct?

 

Good luck with the baby.

[Hummingbird]

EDIT: Used wrong figures, maneuver devices not operating etc.

Edited March 31, 2015 by Hummingbird

[GGTharos]

Clean F-15C with no stores/pylons (but including oil and pilot IIRC) and 50% fuel is 35000lbs eagle. If you put weapons on it it goes up to 38000lbs - 39000lbs, and G available will be less than in the clean config because of drag.

 

Per -1 (or -34, I forget) the empty weight with pilot etc is 28500lbs, unless I'm remembering incorrectly, which is possible.

 

IIRC F-14A empty weight was 40000 and change, F-14B about 41800, F-14D 43000 and change. All AFAIK.

 

As for the lift generators, I agree - you really see this in available AoA. The F-15 gets up to 20 deg stable - you can pull up to 30-35, but it might be a bit icky. You usually sound the AoA warning at 18-20 deg (note it's not a stall warning), in the F-14 there's a stall warning at 38deg (I think I did the math right on that one, because the F-14 shows you a gauge with 'cockpit units' of AoA, going from 0 to 30, representing AoAs from -10 to +40, again, IIRC).

 

The reason you don't want a 50000lbs 'cat with weapons on in this fight is that you have very little fuel - you do one turn in afterburner and suddenly it might be a choice between winning the fight and going home, in other words - losing the fight even if you win it. That's assuming I got my weights correctly (Don't bother arguing for the F-14A, it might be lighter but the fuel efficiency on the TF-30's is so atrocious it's not funny - the 110's burn LESS fuel with MORE thrust)

[turkeydriver]

Clean F-15C with no stores/pylons (but including oil and pilot IIRC) and 50% fuel is 35000lbs eagle. If you put weapons on it it goes up to 38000lbs - 39000lbs, and G available will be less than in the clean config because of drag.

 

Per -1 (or -34, I forget) the empty weight with pilot etc is 28500lbs, unless I'm remembering incorrectly, which is possible.

 

IIRC F-14A empty weight was 40000 and change, F-14B about 41800, F-14D 43000 and change. All AFAIK.

 

As for the lift generators, I agree - you really see this in available AoA. The F-15 gets up to 20 deg stable - you can pull up to 30-35, but it might be a bit icky. You usually sound the AoA warning at 18-20 deg (note it's not a stall warning), in the F-14 there's a stall warning at 38deg (I think I did the math right on that one, because the F-14 shows you a gauge with 'cockpit units' of AoA, going from 0 to 30, representing AoAs from -10 to +40, again, IIRC).

 

The reason you don't want a 50000lbs 'cat with weapons on in this fight is that you have very little fuel - you do one turn in afterburner and suddenly it might be a choice between winning the fight and going home, in other words - losing the fight even if you win it. That's assuming I got my weights correctly (Don't bother arguing for the F-14A, it might be lighter but the fuel efficiency on the TF-30's is so atrocious it's not funny - the 110's burn LESS fuel with MORE thrust)

 

Depends on the altitude right? Of course the F-110s make more thrust, bt the fuel savings is in less use of afterburner and more efficient engine operation at altitude. Down low in the weeds, the TF-30 numbers should be very good as far as fuel efficiency. The F-110 may just edge it, but the TF-30 is a very fuel efficient motor, but this is about turning and burning, and the TF-30 mandates afterburners most of the time in ACM while the F-110 does not, so the new motor wins the fuel fight when maneuvering period. There I go defeating my point in the same post LOL.

[Hummingbird]

Max sustained G-load, flaps & gear up, max afterburner

 

F-14D @ 55,620 lbs (50% fuel) w/ 4x AIM-7's + 4x AIM-9's @ 5,000 ft:

Mach = G-load

0.2 = 1.4

0.3 = 2.3

0.4 = 3.5

0.5 = 4.7

0.6 = 5.6

0.7 = 6.4

0.75 = 6.7

 

F-15C @ 41,000 lbs (50% fuel), w/ 4x AIM-7's + 4x AIM-9s @ 5,000 ft:

Mach = G-load

0.2 = 1.2

0.3 = 2.1

0.4 = 3.1

0.5 = 4.0

0.6 = 5.1

0.7 = 6.2

0.75 = 6.8

 

All figures are straight from the manual and are the basis from which the later maneuver charts derived their figures, and funny enough they show the F-14 maintaining an STR advantage from Mach 0.2 to 0.74, after which point it shifts in favor of the F-15. Proving once and for all that the later ""all in one" charts were slightly off at the low mach numbers, but that if you want specific figures at low mach numbers then the manual provides these as well.

 

Now as can be seen the F-15 pays a price at the low mach numbers for not featuring as extensive a lifting body design as the F-14, as well as lacking the high lift devices for maneuvering flight at high AoAs.

 

The above figures exactly mirror the previous stall speed data.

Edited March 31, 2015 by Hummingbird

[GGTharos]

The F-110 beats the pants off the TF-30 in fuel efficiency at AB.

 

While the TF-30 is technically more efficient at MIL, the F-110 can fly you at such an altitude at MIL that it completely negates any advantage the TF-30 might have dreamed of having, unless it's a MIL power race on the deck - so, in practice, the F-110 also beats the pants off the TF-30 in MIL efficiency also.

 

Depends on the altitude right? Of course the F-110s make more thrust, bt the fuel savings is in less use of afterburner and more efficient engine operation at altitude. Down low in the weeds, the TF-30 numbers should be very good as far as fuel efficiency. The F-110 may just edge it, but the TF-30 is a very fuel efficient motor, but this is about turning and burning, and the TF-30 mandates afterburners most of the time in ACM while the F-110 does not, so the new motor wins the fuel fight when maneuvering period. There I go defeating my point in the same post LOL.

[captain_dalan]

 

As for the lift generators, I agree - you really see this in available AoA. The F-15 gets up to 20 deg stable - you can pull up to 30-35, but it might be a bit icky. You usually sound the AoA warning at 18-20 deg (note it's not a stall warning), in the F-14 there's a stall warning at 38deg (I think I did the math right on that one, because the F-14 shows you a gauge with 'cockpit units' of AoA, going from 0 to 30, representing AoAs from -10 to +40, again, IIRC).

 

 

Unfortunately the alpha conversion is not linear per mach number (at least in the F-14). Those 40 degrees are equivalent to 30 units only at higher mach numbers. Near stall speeds or around mach 0.4 and lower, the 30 units are closer to 25 degrees, which is however not the stall margin. That would be somewhere between 30-33 degrees true alpha with the power on.

[turkeydriver]

Max sustained G-load, flaps & gear up, max afterburner

 

F-14D @ 55,620 lbs (50% fuel) w/ 4x AIM-7's + 4x AIM-9's @ 5,000 ft:

Mach = G-load

0.2 = 1.4

0.3 = 2.3

0.4 = 3.5

0.5 = 4.7

0.6 = 5.6

0.7 = 6.4

0.75 = 6.7

 

F-15C @ 41,000 lbs (50% fuel), w/ 4x AIM-7's + 4x AIM-9s @ 5,000 ft:

Mach = G-load

0.2 = 1.2

0.3 = 2.1

0.4 = 3.1

0.5 = 4.0

0.6 = 5.1

0.7 = 6.2

0.75 = 6.8

 

All figures are straight from the manual and are the basis from which the later maneuver charts derived their figures, and funny enough they show the F-14 maintaining an STR advantage from Mach 0.2 to 0.74, after which point it shifts in favor of the F-15. Proving once and for all that the later ""all in one" charts were slightly off at the low mach numbers, but that if you want specific figures at low mach numbers then the manual provides these as well.

 

Now as can be seen the F-15 pays a price at the low mach numbers for not featuring as extensive a lifting body design as the F-14, as well as lacking the high lift devices for maneuvering flight at high AoAs.

 

The above figures exactly mirror the previous stall speed data.

 

Not even a funny enough discovery. It is widely known that the F-14 and F-15 were designed to fight their best in different flight regimes. The "funny" comes into play when you realize that both forces may have listened to their own history in Korea and Vietnam as opposed to a fighter experience world wide. The F-14 was designed to win every dogfight at low-level and low(er) speed-where Navy kills originated in Korea(slower jets and props-focused on CAS and mud-moving, so these fights were always med/low-altitude and lower airspeed) and Vietnam (classic dogfights still maneuvering to the best envelope for a Sidewinder<navy designed weapon> or gun kill in the case of the F-8. The Air Force kills in Korea occurred with their high flying CAP flights against higher flying MiG-15s, and occurred at higher speeds as the jets built up as much energy as possible when at the edge of their range in MiG Alley. In Vietnam the Air Force had many more Sparrow kills and many high speed sidewinder and even supersonic gun kills. The F-105 MiG kills occurred at higher speeds as well. So the F-15 was built and designed to fight best where all these fights occurred- Mach .8 to Mach 1.2, and you can't beat an F-15 in that envelope unless you're flying an F-22 or Eurofighter.

The F-14 fights better than the F-15 to Mach 0.75 and then again after Mach 1.2( especially if glove vanes are operational). This was designed because the bomber threat was seen to be high speed escorted by MiG-25 types that mandated a high speed intercept and maneuvering.

The epic engineering feats led to two amazing designs that do their assigned jobs very, very well.

[Hummingbird]

The maneuver at 11:20 min (as well as at the end of the video) at high alt with full wing sweep demonstrates the high speed high alpha capability quite well, very impressive:

5GgtkkQ6IN4

Edited April 4, 2015 by Hummingbird

[Hummingbird]

Not even a funny enough discovery. It is widely known that the F-14 and F-15 were designed to fight their best in different flight regimes. The "funny" comes into play when you realize that both forces may have listened to their own history in Korea and Vietnam as opposed to a fighter experience world wide. The F-14 was designed to win every dogfight at low-level and low(er) speed-where Navy kills originated in Korea(slower jets and props-focused on CAS and mud-moving, so these fights were always med/low-altitude and lower airspeed) and Vietnam (classic dogfights still maneuvering to the best envelope for a Sidewinder<navy designed weapon> or gun kill in the case of the F-8. The Air Force kills in Korea occurred with their high flying CAP flights against higher flying MiG-15s, and occurred at higher speeds as the jets built up as much energy as possible when at the edge of their range in MiG Alley. In Vietnam the Air Force had many more Sparrow kills and many high speed sidewinder and even supersonic gun kills. The F-105 MiG kills occurred at higher speeds as well. So the F-15 was built and designed to fight best where all these fights occurred- Mach .8 to Mach 1.2, and you can't beat an F-15 in that envelope unless you're flying an F-22 or Eurofighter.

The F-14 fights better than the F-15 to Mach 0.75 and then again after Mach 1.2( especially if glove vanes are operational). This was designed because the bomber threat was seen to be high speed escorted by MiG-25 types that mandated a high speed intercept and maneuvering.

The epic engineering feats led to two amazing designs that do their assigned jobs very, very well.

 

True, however in a WVR fight I'd sure prefer to be in the F-14 considering that it features a superior STR from stall to Mach 0.74 and an average 1 G advantage in instantanous turns.

[turkeydriver]

True, however in a WVR fight I'd sure prefer to be in the F-14 considering that it features a superior STR from stall to Mach 0.74 and an average 1 G advantage in instantanous turns.

 

Me too, just can't go totally one-sided on this, as the F-15 has a record and performance all it's own, but I'll take a Tomcat any day of the week in ACM.