Comparison of Aircraft Wing Loadings

[column5 62]

No amount of taunting, insults, or Admiral anecdotes will alter hard numbers from objective sources.

 

Clearly you need to take your own advice, as you are the one who entered this thread with accusations of "fudging' numbers as we worked on getting the numbers correct for our various comparisons earlier in the thread. This thread contains some data on a range of aircraft that can be interesting when considered in light of the many discussion here about relative performance and how certain aircraft might perform in roles for which they were not designed. Your own (typical) knee-jerk response to anything that threatens your phantom phantasy has turned it into something else, which is fine by me since you lose that argument every time.

 

Also, you clearly have a reading comprehension problem, evident in most of the threads you post in, but specifically here with regard to quoting Admirals. To bring you up to speed (if that is even possible), Admirals have been referenced three times:

 

1. A quote attributed to Admiral Connelly regarding the F-111B's low thrust/weight ratio.

2. A paraphrase of Admiral Gillchrist's comments on the F-14 wing loading, which supports figures in a published F-14 reference work.

3. A reference to Admiral Gillchrist's comment that first visual identification of the enemy usually leads to victory in ACM.

 

None of these quotes were used to buttress any arguments about aircraft performance relative to one another, except, I suppose in your mind.

[column5 62]

You questioned my F-4 versus F-8 anecdotes because you said they contradicted each other, but they didn't.

 

Again, reading comprehension comes into play here.

 

This is what I actually said:

 

"Individual anecdotes don't serve either side in this debate. For the historian, primary sources are often the most problematic because it is nearly impossible for a person who experiences an event first hand to report on it objectively. Its human nature. In this case, we have two guys saying (and I paraphrase) that their side beat the other side 100% of the time. Clearly, that cannot be true."

 

That is specifically why I have avoided quoting from the voluminous accounts of F-14 pilots, and even from the results of the F-4 versus F-14 trials conducted by the Navy. The weight of the anecdotal evidence is on the side of the F-14, but the individual stories themselves can't be used as definitive proof because pilot skill is so important, and the ego-factor cannot be ignored when evaluating broad statements.

[Caesar 305]

 

"Individual anecdotes don't serve either side in this debate. For the historian, primary sources are often the most problematic because it is nearly impossible for a person who experiences an event first hand to report on it objectively. Its human nature. In this case, we have two guys saying (and I paraphrase) that their side beat the other side 100% of the time. Clearly, that cannot be true."

 

 

x2!

 

Of course, the other problem you'll run into using data points as your only "solid" evidence is that in manuals, to what I've seen, these points are only applicable to pilots/aircrews who would follow the manual to a T. Try calculating the F-14A's turn rate at 12.2G at 600kts. By the 1.1, you can't, but you'd better believe it happened (TACTS range recorded it in a fight vs an F-5E). What about at 10G to evade a SAM over the skies of Iraq during Desert Storm? Again, manual says "plane can't do that". It did. G-limiter pegged to get the hell outta the way. At times, like in the case of the 12.2G yank the objective was specifically to get slow quick, and get the Tiger off the Turkey's tail. End result was a slow speed rolling scissors which the F-5 was loosing after being on the offensive and unable to match the F-14's turn rate from the yank. KIO Deck was called before the Turkey driver called guns on the Tiger. Both the F-5 and F-14 drivers in the incident concur on that point. I use the F-14 in these examples, because it is a plane that I've researched; but the same must hold true for any other jet without hard limiters.

 

For that matter, those charts don't talk about fighting in the full three dimensions of air combat. What is the rudder performance at high versus low speed? Can the plane out-yaw another? How about spoilers or the horizontal tail coupled with the rudder and other surfaces? A common maneuver of Tomcat drivers in a slow fight against a more nimble plane was to use opposite stick to rudder, where at slow speeds, the airplane would generate a high yaw rate in the direction of the rudder/snap roll, keeping the plane's nose on the target, when the target aircraft thought it was getting away. Climb rate with or without flaps? What about at combat altitude? How does the jet perform outside of those envelopes, both on the high side, and on the low side? Clearly that's not going to be in there. A lot of this has to come from the folks who flew the jets, because they were pushing them beyond the envelope, outside of the area covered in the manuals.

 

I also continuously hear from pilots who "grew up" in the era before all-aspect heaters (Hoser, Turk, Hawk, Snort, and various pilots they flew with and against) that dogfights could commonly turn into slow-speed ordeals (even F-4 vs F-4), where the pilot with the better handling of his aircraft at such speeds (under 200kts), especially in a scissors (regardless of type vs. type, and executed time and again against smaller aircraft) would be the ones who came out on top. Today, that might not be as much the case, as most modern fighters at combat weight have better than 1:1 Thrust to Weight ratios (F-14B/D, F-15A/C, F-16C, MiG-29, etc.) and so can sustain energy better; but the idea that fights don't get slow, or that dragging an opponent to a slower speed than his own max performance speed doesn't happen seems ludicrous to me.

 

Even more, looking at the weapons systems of today, high off-boresight missiles have massively changed the dogfight; the first person to get the target within 60-degrees of the nose is going to have the first shot. It's quite a bit different now.

Edited May 28, 2010 by Caesar

[+streakeagle 865]

What clear evidence on the F-8? Give me a link or scan any reference that isn't an F-8 pilot saying F-8s always beat F-4s in ACM. No one ever did in the other thread devoted entirely to assessing F-8 maneuverability, I don't expect anyone can or will produce one now. The only data I could find on the F-8 clearly showed that the two aircraft were very close and that which one was better would depend on the specifc altitude and speed being compared. How does that equate to a clear advantage for the F-8?

 

None of the F-4 performance (or any other aircraft) I have ever cited has ever been fantasy. I cited a specific point for the purposes of a simple, precise comparison to disprove the statement that an F-4 could never out turn an F-14 even with slats. The official data directly shows that a slatted F-4 actually could turn better than an F-14. The point I cited at Mach 0.9 at 10,000 feet isn't just some arbitrary point on the envelope where the slatted F-4 just happens to be better than the F-14. It is a major performance benchmark for contract flyoffs. The aircraft which is superior at Mach 0.9 and 10,000 feet is generally better over the entire subsonic envelope from sea level to 20 or 30 thousand feet. But my point never was to show that the F-4 is better than the F-14, but to back my original statements in many threads over many years that the F-14's performance was a marginal improvement over the F-4. The F-14's position on the wing loading chart should never have been modified to make it look better. Its high wing loading combined with its mediocre thrust ratio (both of which clearly apparent on your chart if you don't alter the numbers) is the reason why it was the worst performing aircraft of the teen series. It is your fantasy to selectively alter the wing loadings on your chart to favor specific aircraft. It should be noted that all the comparisons I have seen between F-14 and F-4 have been against the unslatted F-4J. I don't have the flight manual or charts for the F-4S, but the slatted F-4E should be close enough. Its max AoA is similar to the F-14 and its instantanous performance very close to the F-14A. The Aero book openly admits that the F-14A has a lower T/W ratio than an F-4J, but the F-14 is still going to accelerate better due to its lower CD0. For all the advantages slats offered to the F-4, there was one penalty: an even higher CD0.

 

Wing loading by definition is W / S, where S is the reference area of the wing design. It is specified during the design process as an unchanging reference to make all other aerodynamic coefficients meaningful. You don't change S because some book mentions how other parts of the aircraft contribute to lift. Almost all aircraft generate lift with parts other than their wings, but the effective lift is by definition accounted for in CL not S.

 

Wing loading comparisons are common for several reasons: the numbers needed to calculate wing loading are readily available, the calculation is simple, and if both aircraft have similar wing designs, it can be very accurate. But if the wings differ too much in aspect ratios, wing section profiles, lift devices, etc., it can't be used to judge relative performance at all. If your goal is to accurately show relative performance, why are you plotting wing loading? Not only does it not account for lifting bodies and LERXes, but misses slats, flaps, and wing section. Why not pick a Mach and an altitude and plot actual performance for all of the aircraft? Max instaneous lift load accounts for almost everything by including CL ( CLmax * S * q / W ). The only components missing are thrust and drag. If you want to account for everything in one shot, plot max sustained G... not because dogfights are won by flying in a constant circle, but because they are won by exploiting a combination of specific excess power and agility directly reflected by an aircrafts max sustained g.

 

Your current chart plots purely W/S for most aircraft and some form of W/(CL*S) for those aircraft whose wing loadings you don't like. So it doesn't compare wing loadings or relative performance. Of course it is your chart and you are free to plot any points anywhere you want them. It is not my numbers that are "selective" or "fudged". I have always posted scans of entire performance charts and only select points to simplify comparisons and save time. I do not pick one number I don't like and change it to whatever I feel it should be. If you came up with an aerodynamically correct approach for figuring out the "effective wing area" for every plane on the chart instead of just the F-14, I would never have accused you of fudging the numbers. Instead, you take one discusssion limited to only the F-14 and twist it onto your chart. On the next page in the book is a comparison of CL curves for the F-14, F-4, and MiG-21, there is where your "effective area" is factored in to aero equations. Doing the math ( CL / (W/S) ) will quickly show you why the F-14's instantaneous performance chart looks so much better than the F-4 and only marginally better than the MiG-21. But beware, the F-4 curve stops at about 13 degrees, when the unslatted aircraft have a safe white mark for max g that is about 18 degrees, so the CLmax for the F-4 on the book chart is about 72% of what it should be. Find or estimate CLmax for all of the aircaft on your chart and divide the wing loading by that value and you will have a chart that (1) provides useful information and (2) realistically ranks the F-14 where it should be. Otherwise, my accusation of "fudging" isn't a taunt or an insult, it is by definition what you did to your wing loading table.

[column5 62]

Your current chart plots purely W/S for most aircraft and some form of W/(CL*S) for those aircraft whose wing loadings you don't like.

 

Skipping over all of your other BS, I do want to address this for anyone who happends to come along and wonder about the charts. The formulas used in all of the charts are the same for each aircraft. Refinements will be made when published data can be found for the trickier aircraft such as the F-14, F-18 and F-16.

 

I thnk we can all see from yet another rambling, venom-filled post that you are the one who is so desperately trying to defend your pet aircraft that you refuse to even read much less comprehend what other people are saying.

 

I will give you credit for one thing, though. Being so wrong, so consistently in the face of an entire body of published reference material takes some chutzpah.

[column5 62]

Of course, the other problem you'll run into using data points as your only "solid" evidence is that in manuals, to what I've seen, these points are only applicable to pilots/aircrews who would follow the manual to a T.

 

Apparantly some of the early criticism of NATOPS revolved around the idea that standardization would kill creativity. Its a great point you make though that the information published in flight manuals does not cover the entire flight envelope, but only that part of it deemed "safe' for normal operations.

[column5 62]

Even more, looking at the weapons systems of today, high off-boresight missiles have massively changed the dogfight; the first person to get the target within 60-degrees of the nose is going to have the first shot. It's quite a bit different now.

 

<sigh> Yeah, that is why it is difficult for me to get as excited about cutting-edge military aviation as I am about that of the 1970s and 80s.

[column5 62]

Apparantly, streakeagle developed this problem at an early age...

 

[DWCAce 19]

I think another item to look at the mission each a/c was designed for. Each one has different design requirements, and as always, compromises.

[MigBuster 2,863]

Refinements will be made when published data can be found for the trickier aircraft such as the F-14, F-18 and F-16.

 

 

 

If its any use - this is from former senior F-16 Test Pilot Joe Bill Dryden:

 

This negative static margin provides one reason the F-16 turns as well as it does. What you may recall from Aero 101 no longer applies when you try to evaluate the F-16. I’ve seen articles in Air Progress that show how the F-15 will turn so much better than the F-16 because the F-15’s wing loading is lower. But this is where people get in trouble, because you can no longer apply wing loading to come up with a prediction as to how the airplane will turn.

 

Let me explain this. Since the F-16 is negatively stable, the tail is lifting in order to control the AOA (while you’re subsonic). And while the center of pressure shift is such that the F-16 6 is positively stable when you’re supersonic, the amount of down force necessary to keep the aircraft trimmed to a given AOA is less than conventional fighters. As a result, the total lift acting on the airplane is more for a given AOA; therefore, the resultant induced or trim drag is reduced. Less drag of any kind means better sustained turn and cruise performance. Also, the F-16 has been designed to take advantage of the vortex lift generated by the strakes. This vortex is what you see trailing back on both sides of the F-16 when you turn it hard in moist conditions. They are not there just for more oooohhs and aaaahhs at air shows.

 

As a result of this vortex lift, there are areas in the flight envelope where as much as thirty percent of total lift is coming off the fuselage. If you fall into the same trap that Air Progress did and take the gross weight of the aircraft divided by the projected wing area, you’ll come up with a wing loading of about sixty-five pounds per square foot. But (and this is a very big but), when you add in all the contributions of both tail and fuselage lift, you’ll come up with a wing loading of about forty pounds per square foot. Now you’re talking late World War II wing loadings. Can you now understand why you keep hearing, "I never thought you’d be able to make that corner!" Heard that in some of your debriefings? Ah haaaa! Then maybe there is some method in their madness.

 

So it’s really a combination of these two things that gives the F-16 the different characteristics we have to account for when beginning to fly this multirole fighter. The negatively stable aero and the rate command flight control system both go to make up a fighter that’ll perform like no other!

[Toryu 156]

If you want to account for everything in one shot, plot max sustained G... not because dogfights are won by flying in a constant circle, but because they are won by exploiting a combination of specific excess power and agility directly reflected by an aircrafts max sustained g.

 

Exactly.

Wingload and T/W won't give you any reliable account als long as L/D, CD, SEP and CLmax aren't considrered.

 

 

By that chart, the 104 wold be a dog, yet when it was flown in Projects Featherduster I and II, it pretty much waxed any opponent (including 102s, 106s and F-8s), clearly winning both evaluation-programmes as "best american dogfighter below 20,000 ft".

That's because the 104 was the SEP-king of it's age and could quickly turn speed into G or recover from excesive energy-bleed, while others aimed for AoA and high instantaneous turn-rates, killing their TE.

 

 

Fun fact: with T/O-flaps at M0.85 , the 104G (T/W-dog of the family) could sustain about 7g below 5,000ft and at 2000lbs internal fuel.

That came as an ugly surprise for lots of hotrod-jockeys, looking for an easy kill

[Erwin_Hans 6]

C5.....Why MiG-21PFM is better than F-16A and F-18C?

[JediMaster 451]

Because it weighs less?

[column5 62]

C5.....Why MiG-21PFM is better than F-16A and F-18C?

 

One answer is, as JediMaster says, it is lighter with a very good thrust to weight ratio. Another answer is that due to advanced aerodynamic designs, the F-16 and f-18 both make up for their "poor" paper performance with much better real-world perofrmance. You can't use the charts I made to prove that one aricraft is definitively better than another...well except in the case of the F-111B being a dog...but you can use them as a starting point for making more in-depth comparisons.

 

I think that the MiG-21 is underrated because it has traditionally been flown by pilots who received poor instruction in poor tactics. I would hazard to guess that a Red Eagles pilot flying the 21 would have gotten much more out of the plane, and could have beaten an F-16 or F-18 despite their technological advantage. I also think that the way the AI handles the MiG-21 in the SF series reinforces the misconception about the 21 not being dangerous.

[Erwin_Hans 6]

Found these.

 

Maybe MiG-21 need a good pilot.

 

[DWCAce 19]

I think the MiG driver needs to do some ID... that's an F-16.

[FastCargo 412]

Also, like the famous 'F-22 in the F-18 sights' photo, context is everything. There is no information on what was going on in those pics. Now, I'm NOT saying they weren't valid 'kills', but until you know the full story, you don't know dick.

 

FC

[+Gocad 26]

I think the MiG driver needs to do some ID... that's an F-16.

 

Erm, perhaps you need some refreshing since the aircraft in the left image is indeed a F/A-18

Edited August 2, 2010 by Gocad

[JediMaster 451]

Yes, first is a Hornet and the 2nd is an F-16. I noticed the F-16 still has his underwing tanks on, so he's not pulling many g's.

[DWCAce 19]

Erm, perhaps you need some refreshing since the aircraft in the left image is indeed a F/A-18

 

I see that now, thought it was only a graphic for the website, with the pic below being the exhibit.