F-14 vs F-15 vs F-16

[renrich]

I don't claim to have the tech expertise of most of you, but have always liked the F14 a great deal and have at least one good book about the design and development of the Tomcat(as well as the F15.) Also had a long conversation with a Tomcat driver at an airshow in (believe it or not) Gunnison, CO. The book states that F14 was designed at first as a kind of "sniper" with a lot of loiter capability. To lie in wait for enemy bombers like the Backfire and shoot them down from long range with the Phoenix. When the Navy pilots began to turn and burn with the Tomcat it was found that the PW engine it was equipped with did not handle well the sudden and frequent throttle inputs. Thus the eventual switch to the GE engine. I have read that the F14 performance is not much degraded by the weapon stores because the weapons are carried conformally(in the tunnel) whereas weapons carried under wing like the F15 and F16 and F18 significantly impact performance. Can youall illuminate that factor. I still theorise that a newly manufactured Strike Tomcat would have served our Navy better than the F18 E-F.

 

[parsifal]

I cant compete with any of the experience here, so im going to do the smart thing and respect it. I do know that the in the RIMPAC excercises I attnded in the early 80's, the F-14 was not considered to be just a bomber killer, or anything inferior....in fact the USN guys, and the RAN PWOs I worked with/for viewed the ship as the "queen of the battlefield"

I remeber at one part of one excercise, they downgraded the performace and limited the maximum engagement ranges of the Tomcats defending Constellation (I think....my memory is starting to fade). The attacking A-4s were given some standoff capability. With those paparameters injected into the excercise, our A-4s managed to slip past and disable the carrier, which was then finished off by an Oberon submarine.

However, until the excercise was modified to significantly downgrade the performance of the Tomcats, we could not even get close.....there was never any talk of the Phoenix being second rate then. We, as the "opposing" force, knew what was going to happen to our strikes.

Against the F-111s it was much closer and interesting . Again the F-111s were assumed to possess stand off weponary (something they did eventually acquire)......I remember this was the only time I saw F-111s going supersonic at a height of about 60 feet....but thats another story.......IIRC the defending CAP was decoyed (I think it was a USAF squadron of either F-15s or F-4s....i dont recall) alowing the F-11s to race in and deliver the strike. Because of the speed of the F-111s, the F-14s found it difficult to vector to an early point of interception

Anyway, the overriding determinant in successful air combat effectiveness is pilot training and detection. Without either of those, it doesnt really matter what gadgetry or theoretical performance you possess. If you dont know how to use it, you are history..


Here is a U-Tube vid that might help to illustrate


View: https://www.youtube.com/watch?v=zZyvY3n9GDY

 

[parsifal]

I also thought this reconstruction of the Gulf of Sidra incident might be interesting to some


View: https://www.youtube.com/watch?v=zSimVE5NyMw

 

[SoD Stitch]

Can youall illuminate that factor. I still theorise that a newly manufactured Strike Tomcat would have served our Navy better than the F18 E-F.

You are more or less right about the carriage of weapons on the Tomcat. Also, Soren had a good point early on in this discussion about the body contributing to the overall lift of the a/c, especially with the "tunnel" between the two engines; it was especially good in high A-O-A flight regimes. When it was designed, the F-14 had the most aerodynamically efficient airframe of any a/c in the world, until the advent of the Su-27 family of a/c (yes, even better than the F-15 F-16). Since it was designed to spend a lot of time "loitering", as renrich said, it had to be efficient, if it was to have sufficient range. The carriage of the Phoenix's was somewhat mitigated by the use of aerodynamic "pallets" to carry the missles, which made them more streamlined than if they were just hung by conventional bomb shackles.

 

[drgondog]

Ugh... here comes another meltdown.

There is a common root cause to most of the meltdowns.....

 

[drgondog]

You are more or less right about the carriage of weapons on the Tomcat. Also, Soren had a good point early on in this discussion about the body contributing to the overall lift of the a/c, especially with the "tunnel" between the two engines; it was especially good in high A-O-A flight regimes. When it was designed, the F-14 had the most aerodynamically efficient airframe of any a/c in the world, until the advent of the Su-27 family of a/c (yes, even better than the F-15 F-16). Since it was designed to spend a lot of time "loitering", as renrich said, it had to be efficient, if it was to have sufficient range. The carriage of the Phoenix's was somewhat mitigated by the use of aerodynamic "pallets" to carry the missles, which made them more streamlined than if they were just hung by conventional bomb shackles.

If anybody has the L/D data for both ships the question of aerodynamic efficiency would quickly be solved. Does anyone have this at their fingertips or are we about to get into the usual low fact base arguments?

This is not directed at you DoD.

Strakes were used for all three ships in question and the F-16 also had a variable camber wing to change CLmax (at expense of more drag) in high G manuevers.

Although this is extracted from Wikipedia I can vouch for the information and context personally - the Vought engineers were experimenting with different geometries on the strake and could not achieve a better design than GD.



"Wing and strake configuration
Aerodynamic studies in the early 1960s demonstrated that the phenomenon known as "vortex lift" could be beneficially harnessed by the utilization of highly swept wing configurations to reach higher angles of attack through use of the strong leading edge vortex flow off of a slender lifting surface. Since the F-16 was being optimized for high agility in air combat, GD's designers chose use a slender cropped-delta wing with a leading edge sweep of 40° and a straight trailing edge. To improve its ability to perform in a wide range of maneuvers, a variable-camber wing with a NACA 64A-204 airfoil was selected. The camber is adjusted through the use of leading-edge and trailing edge flaperons linked to a digital flight control system (FCS) that automatically adjusts them throughout the flight envelope.[39][31]

This vortex lift effect can be increased by the addition of an extension of the leading edge of the wing at its root, the juncture with the fuselage, known as a strake. The strakes act as a sort of additional slender, elongated, short-span, triangular wing running from the actual wing root to a point further forward on the fuselage. Blended fillet-like into the fuselage, including along with the wing root, the strake generates a high-speed vortex that remains attached to the top of the wing as the angle of attack increases, thereby generating additional lift. This allows the aircraft to achieve angles of attack beyond the point at which it would normally stall. The use of strakes also permits the use of a smaller, lower-aspect-ratio wing, which in turn increases roll rates and directional stability, while decreasing aircraft weight. The resulting deeper wingroots also increase structural strength and rigidity, reduce structural weight, and increase internal fuel volume.[40] As a result, the F-16's high fuel fraction of 0.31 gives it a longer range than other fighter aircraft of similar size and configuration"

 

[SoD Stitch]

If anybody has the L/D data for both ships the question of aerodynamic efficiency would quickly be solved. Does anyone have this at their fingertips or are we about to get into the usual low fact base arguments?

This is not directed at you DoD.

I understand.

And, no, I do not have those figures handy, I just remember reading that somewhere; I'll see if I can find my source over the weekend, perhaps there will be more there to enlighten me . . . . .

 

[drgondog]

True, but the F-14's wings are more lift efficient, creating more lift pr. area when folded out. The span-loading, which is a good indicator of turn performance according to some as an a/c rides on a cylindrical tube of air, suggests that the F-14 is the best.

If you look closely the area of the F-14 wing is exactly the same extended or tucked. The AR improves when deployed forward and that will help in the subsonic - at low altitude I am not even sure the F-14 can make Mach 1 but confess I am not sure...

if you wish to hang your thesis on the F-14's low speed flight qualities, have at it. It probably will out turn an F-111 and maybe out turn an F-15 or 16 at speeds below say 350 kts - but because the F-15 and F-16 have more energy and acceleration why does either one have to play by those rules? And this is only a low possibility as the Wing (Lift) loading for both the -15 and -16 is so much better.

You should have to provide some data and conditions to justify your statement.

Between 400 and 600 kts, Having auto sweep controls while manuevering in the transonic 'would be interesting' as transonic flow is extremely unpredictible at one speed and geometry much less 'in transit'

You said the F-14 wings are more 'Lift Efficient' - you have the L/D for the wing handy? and for the F-16 and F-15?

Can you paint a picture of the 'cylindrical tube of air' and perhaps reference the contrast of the air geometry the F-15 and F-16 that is different? And then maybe slide over and give us a tutorial regarding the benefits

You mention 'span loading' into your argument. You first provide a definition for what you mean, then do you have data on 'span loading' for all three ships and you can put your definition in context? and you will show how 'span loading' translates to 'turn performance'. This pre supposes that you have not confused 'span loading' with 'lift loading'??

 

[drgondog]

I understand.

And, no, I do not have those figures handy, I just remember reading that somewhere; I'll see if I can find my source over the weekend, perhaps there will be more there to enlighten me . . . . .

The key would be the ability to look at L/D for both swept and extended configs for the F-14 as the L/D for full sweep should suck in comparison to fully deployed.

The second key would be some intelligence regarding the control functions over sweep as a function of airspeed.

I actually am interested. At top Gun the instructors stayed with A4 as the F-4s were phased out and the F-14s were moving in.

The Top Gun instructors delighted in whipping hot rock Lieutenants and Lt Commander butts with the A4 when they 'forgot' and elected to turn with the A-4. The A-4 was fixed geometry, low T/W ration and delighted in whacking F-14s when they forgot about power and energy.

The F-15 has just a slight WL (Lift Load) disadvantage to the A-4 and the F-16, while 20% higher than A-4 (but 20% lower than F-14) has a nifty variable camber wing, and negative stability made it a beast in ACM.

This debate reaaaally needs some more facts as one will never get an Navy guy admitting any Air Force a/c can whip his ass (and vice versa).

Having said that the F-14 was not a 9G a/c with first models and got worse as the weight was piled on. I would have to see what was changed about the F-15C also as its Gross weight increased over the A (primarily fuel). Ditto F-16.

Another observation. The F-14 is a lot like the Mustang as range and speed were essential fleet defense criteria - so the F-14 would almost always be fuel heavy going into a fight.

 

[kool kitty89]

The VFAX was the USN version of the F-16. IIRC the XL was the delta wing variant.

Vought died (as a prime) because President Sol Love (as a former engineer) believed two things - one the F-16 was a better ship than the F-18 and, two he believed the Navy would comply with the congressional mandate that the Navy buy the winner of the USAF fly off between the F-16 and F-18.

1976.

The XL was the delta version, it was the competitor for the F-15E for the ATF competition.

And technically it was the YF-17 that lost to the F-16 as the LWF, the F-18 came later. (albeit as a development of the YF-17) The VFAX F-16 was the LTV Aerospace (Vought) Model 1600/1601/1602.

 

[kool kitty89]

Would the F-15 benefit from vortex formation in high AoA maneuvers as well? It doesn't have the root extentions for this purpose, but given the planform it would seem probable to experient the phenomenon to some extent being similar to a Delta. -Delta wings being well known of having this property, hence the extreme nose-high landings, first discovered by Yeager in the XF-92.-
(I know the F-18 has similar root extentions as the F-16 as well)

And the unswept F-14's wings would also have a thicker "true" airfoil section, which would increase the wing's Clmax, spanwise flow will also be reduced. Of course this still gives us no comparison on the lift abilities of these 3 aircraft

Though the higher thrust/weight alone of the other 2 will give them the energy advantage, and better maneivering ability at higher speeds and in the vertical. And the advantage of relaxed stability with FBW of the F-16. (though the F-15 gained some extra maneuvering ability with the addition of FBW too)

 

[SoD Stitch]

I actually am interested. At top Gun the instructors stayed with A4 as the F-4s were phased out and the F-14s were moving in.

They've actually transitioned to F-16N's and late-model F-14's painted as adversary a/c, but I understand some of the older instructors reaaally miss the "Scooter"; it may not turn as well as an F-16, but it had a better roll rate and was slightly smaller than the -16 making it harder to see.

 

[FLYBOYJ]

I cant compete with any of the experience here, so im going to do the smart thing and respect it. I do know that the in the RIMPAC excercises I attnded in the early 80's, the F-14 was not considered to be just a bomber killer, or anything inferior....in fact the USN guys, and the RAN PWOs I worked with/for viewed the ship as the "queen of the battlefield"

I remeber at one part of one excercise, they downgraded the performace and limited the maximum engagement ranges of the Tomcats defending Constellation (I think....my memory is starting to fade). The attacking A-4s were given some standoff capability. With those paparameters injected into the excercise, our A-4s managed to slip past and disable the carrier, which was then finished off by an Oberon submarine.

However, until the excercise was modified to significantly downgrade the performance of the Tomcats, we could not even get close.....there was never any talk of the Phoenix being second rate then. We, as the "opposing" force, knew what was going to happen to our strikes.

Against the F-111s it was much closer and interesting . Again the F-111s were assumed to possess stand off weponary (something they did eventually acquire)......I remember this was the only time I saw F-111s going supersonic at a height of about 60 feet....but thats another story.......IIRC the defending CAP was decoyed (I think it was a USAF squadron of either F-15s or F-4s....i dont recall) alowing the F-11s to race in and deliver the strike. Because of the speed of the F-111s, the F-14s found it difficult to vector to an early point of interception

Anyway, the overriding determinant in successful air combat effectiveness is pilot training and detection. Without either of those, it doesnt really matter what gadgetry or theoretical performance you possess. If you dont know how to use it, you are history..


Here is a U-Tube vid that might help to illustrate


View: https://www.youtube.com/watch?v=zZyvY3n9GDY

Good Info....

In the 98 RIMPAC I participated in the F-15 were being used to harass the carrier fighter cap. From what I remembered they were being sent out in flights of 2 and 4. When they reached the carrier group they were engaged by either F-18s or F-14s. From what I was told the F-15s chews up the -14s but had a harder time with the 18s. This was off the coast of Hawaii.

 

[Soren]

Bill,

The F-14 features a variable camber wing as-well, LE flaps. The reason we can safely assume that the F-14's wing is more efficient is the much higher AR of the wing.

And as to Span-loading:
"Aspect ratio and planform are powerful indicators of the general performance of a wing, although the aspect ratio as such is only a secondary indicator. The wingspan is the crucial component of the performance. This is because an airplane derives its lift from a roughly cylindrical tube of air that is affected by the craft as it moves, and the diameter of that cylindrical tube is equal to the wingspan. Thus a large wingspan is working on a large cylinder of air, and a small wingspan is working on a small cylinder of air. The smaller cylinder of air must be pushed downward by a greater amount in order to produce an equal upward force; the aft-leaning component of this change in velocity is proportional to the induced drag. Therefore a large downward velocity is proportional to a large induced drag."

 

[Soren]

If you look closely the area of the F-14 wing is exactly the same extended or tucked.

Ofcourse, the wing merely sweeps back and forth, it doesn't alter shape

 

[Matt308]

These are fascinating discussions about aircraft aeronautical qualities. And certainly in a "fighter" aeronautical capabilities debate are of utmost importance during the merge.

What I do find a bit intriguing, however, is the lack of discussion of aircraft engagement doctrine. Here is where I believe the discussion should really reside. So far, the thread is focusing upon ability to maintain max-E for the airframe in question. And that's not an illegitimate argument.

However, FlyBoyJ noted way back that perhaps an engagement might be ended BEFORE the merge. Is this thread limited to modern day worst case operational scenario discussion of where situational awareness derived from other assets are discarded, ECM of a defensive package are ignored, AESA RADAR capabilities are marginalized and netcentric operations have been compromised? If so, the F-22 is then likely nothing to terribly special other than inability to lock-on in certain engagement aspects.

Again, I'll ask what the scenario is supposed to be. If it is a 1-v-1 headlong engagement at short range with ANY modern fighter aircraft, I would suggest that you have just leveled the playing field and predict that virtually any aircraft might result the victor, plus or minus.

While it might be argued that herein lies the US Achilles Heel with respect to ROE, I might agree. But I thought we were talking capabilities.

See what I mean?

 

[SoD Stitch]

However, FlyBoyJ noted way back that perhaps an engagement might be ended BEFORE the merge. Is this thread limited to modern day worst case operational scenario discussion of where situational awareness derived from other assets are discarded, ECM of a defensive package are ignored, AESA RADAR capabilities are marginalized and netcentric operations have been compromised? If so, the F-22 is then likely nothing to terribly special other than inability to lock-on in certain engagement aspects.

You are correct, Matt; in fact, my understanding of current ROE is that there should never BE a merge to begin with. In theory, the enemy assets should be "taken out" before they ever become a real threat to any US assets, which means, preferably, BVR battles with AMRAAM's and, in a worst-case scenario, AIM-9's M-61's. AFAIK, no US F-15 has been forced to participate in a "knife fight" with an adversary a/c (though I'm sure the Israelis have), so we really don't know how a US F-15 (or F-14 of F-16) would perform "in the merge" with an adversary a/c, we can only speculate. So far, US tactical doctrine has worked to minimize losses.

 

[kool kitty89]

Soren, the F-14's wing is going to be able to produce more lift at lower sweep angles than at higher sweepback angles and with a higher lift/drag ratio. (due to the thickening of the "real" airfoil, reduction in spanwise flow, and increase in span-thus AR)

But this says nothing about how the F-15 and F-16's wings will compare in terms of lift/drag and the wing's maximum lift per the aircraft's weight. (so called "liftloading")Not to mention differences in critical AoA of these aircraft. (and other it ignores roll-rate entirely -somthing I assume would decrease on the F-14 as the wings extend -the F-16 probably being the best)

And even if the F-15 did have a lower lift/drag ratio than the F-14 (which it would apear likely at lower speeds), the Eagle's significantly better thrust/weight will probably more than make up for this.


Additionally, your friend's comparison with the sistained G values is only useful for comparing sustained turns. And plain old turn-fighting isn't very commonly used. (though it would seem that this may be the only advantageous area for the F-14)


It's kind of like comparing a Hurricane with a Spitfire, or a Buffalo with a Corsair. The older plane's going to be able to out turn the other, but the newer ones will be able to out run, out flimb, out accelerate their opponenst. (and probably out-roll them too)

Ofcourse, the wing merely sweeps back and forth, it doesn't alter shape

The area could have decreased if the trailing edge of the wing root retracted into the fufalage. (as was the case of the Me P.1101 V1 and Bell X-5)

 

[DerAdlerIstGelandet]

My favorite is the F-14, but this is not about favorites. As for best, for me it can not be the F-14. Why? Of the 3 aircraft it was the least cost efficient, most maintenance intensive, and had the worst flight hours per maintenance hours.

I have a close friend that I work with. He was a US Navy F-14 mechanic before he switched over to the Army to become a Blackhawk mechanic. He said that it was a fight to keep the F-14s in the air. They were very maintenance intensive and broke all the time. He also said that they were very expensive to maintain.

He said great aircraft when it was in the air but it was a bitch to keep them flying.

My friends, the reasons stated above are why the Navy retired the F-14. Of the 3 aircraft it is not the best one...

 

[FLYBOYJ]

However, FlyBoyJ noted way back that perhaps an engagement might be ended BEFORE the merge. Is this thread limited to modern day worst case operational scenario discussion of where situational awareness derived from other assets are discarded, ECM of a defensive package are ignored, AESA RADAR capabilities are marginalized and netcentric operations have been compromised

You are correct, Matt; in fact, my understanding of current ROE is that there should never BE a merge to begin with. In theory, the enemy assets should be "taken out" before they ever become a real threat to any US assets, which means, preferably, BVR battles with AMRAAM's and, in a worst-case scenario, AIM-9's M-61's. AFAIK, no US F-15 has been forced to participate in a "knife fight" with an adversary a/c (though I'm sure the Israelis have), so we really don't know how a US F-15 (or F-14 of F-16) would perform "in the merge" with an adversary a/c, we can only speculate. So far, US tactical doctrine has worked to minimize losses.

That says it all guys - this thread was trying to place modern combat aircraft in a perspective found 60 years ago. "Fight in the horizontal?" Come on!

I have a close friend that I work with. He was a US Navy F-14 mechanic before he switched over to the Army to become a Blackhawk mechanic. He said that it was a fight to keep the F-14s in the air. They were very maintenance intensive and broke all the time. He also said that they were very expensive to maintain.

He said great aircraft when it was in the air but it was a bitch to keep them flying.

My friends, the reasons stated above are why the Navy retired the F-14. Of the 3 aircraft it is not the best one...

I served with several former F-14 mechs - when they came into a P-3 squadron, in their words "It was like going on vacation."

Why don't you look in the POH of each aircraft and it will tell you the exact data you are looking for.

Don't have it FLYBOYJ, and I doubt most people do

F-15 A "EAGLE" McDonnel Douglas FLIGHT MANUAL - eBay (item 120322079827 end time Oct-28-08 19:30:33 PDT)

F-14 D "TOMCAT" Grumman NATOPS FLIGHT MANUAL - eBay (item 110302869510 end time Oct-29-08 06:05:08 PDT)

RARE F-16 A&B General Dynamics F-16 FLIGHT MANUAL - eBay (item 110302759750 end time Oct-28-08 19:30:32 PDT)