Retired flight instructor, CPA. As I was watching your videos, I knew only a pilot could have your understanding, at the end of this video you gave it away you had this knowledge, I like your quick and fast definite way of getting your point across. THANKS.

Not sure how many of you noticed, but turn rate varies greatly by speed and altitude. In short just about any plane in WW2 if jumped, the enemy plane was usually in a dive carrying extra speed from the dive, could out turn the enemy by the simple fact your speed is lower. The faster plan could not turn with you. Then the turn radius between different aircraft types all had a best altitude at which it could turn faster than at any other altitude. However no two aircraft shared this same altitude. Means at altitude X airplane Y could outturn airplane Z at same airspeed, but change the altitude and airplane Z could likely outturn airplane Y at same speed. You wanted to fight at the altitude that your plane had the advantage. WW2 flight sims do not model this at all. I add this in because most people only experience with flying is in a flight sim. And you need to know the flight sims are not very accurate as compared to real life flying.

I wish the War Thunder developers would spend some time watching your videos. Good stuff.

My RAAF 77 Squadron Technical Officer had flown P51 Mustangs during the Korean War. He told me they would lose in practice 1v1 against RNZAF Corsairs because the Corsair could sustain turn ' energy ' better. Mustang is an energy fighter better suited to ' shoot and scoot ' rather than ' turn and burn '

Your vids begin to answer many questions that have hung up discussions "forever". On top of that, you relate things in concrete terms us laymen can grasp that otherwise might have remained mystical. I'm not a pilot, more historian, but history is rife with technology and tech solutions. Love it! "Speed and bank angle"! Can't thank you enough.

Fantastic Reference, Aerodynamics for Naval Aviators is a hidden gem.

This is a remarkable piece of work. Well articulated and very substantial. I learn a ton from this posting. Thanks for the effort and work.

I'm very sorry that I saw only now this very interesting video regarding the comparative speed, angle of attack and other factors versus other airplanes including of course the Me 109! Thanks for enlightening me and I will look forward to to see more of your videos! Thanks!!

The presentation that separates the aviator men from the video game fan boys! Aerodynamics for Naval Aviators was handed to us first day at Pensacola! Thanks.

Greg, I really love your videos, because you make the complicated understandable.

I love the pace, information, topics, etc.! Your videos ROCK! Ehhh, forgive the unfortunate choice of words. :)

Well done, as usual. I'm neither pilot nor engineer, but find this stuff fascinating because my Dad was a Navy pilot in WW 2 (46 missions in an F6F off the Lexington in 1944 with VF-19, then rotated back home for a transition to the F4U-4 and 9 months of training with VBF-150 until war's end), then a test pilot with McDonnell Aircraft postwar (XF-85, XF-88, F2H, etc.). I'd love to see a similar comparison of those two very successful WW 2 Navy fighters vs. the Zero, the Ki-44 ("Tojo"), or the Ki-84 ("Frank"). Carrier warfare made very different demands on an airframe, pilot and engine than did the higher-altitude fighting more common in Europe.

Your videos keep popping up as recommended for me to view by KZfaq. . . I guess I'll have to subscribe. I enjoy what I've seen thus far. :-)

I recently got a request for a 109 vs P51 turn radius analysis. I'll do that in the next couple weeks, along with a DR1 vs. Camel in Rise of Flight analysis.

The P-51’s first notch of flaps can be employed up to ~400 mph, but it seems that the 109’s flaps are more effective when used below the activation speed limit which is > 200 mph.

These videos remain the Gold Standard.

Very good presentation sir! Your content is awesome a pleasure to watch.

haha....got me... I had to rewind to take another look.. A36 Apache ground attack aircraft. I remember this one from reading up on the Mustang history in William N Hess's P51 Bomber Escort book.

Great vid, as usual. Thanks Greg.

First off, thanks for the links Greg! I’ve got a PDF copy of the navy book on my iPad now! After a second look, it was an A36 Apache. Nice! And I’ve been there to see that in person.

So many factors in performance and dogfighting I never even considered! And it brings to light what a true high performance aircraft would of had to he able to do back then to really hold a helpful advantage.

And a lot of the difference in performance can be attributed to the regime in which the plane was intended to fight. The NACA Roll rates at speed chart helps with this (as you already know).

Excellent video, A+ for content. Narration was professional. Thank you

Surprising revelations, well done.

Thanks Greg, great presentations.

Well done Thank you for posting.

I absolutely love your meticulous research and data presentation, looking forward to a P-51 vs. 109 turn radius analysis video (and maybe add a spitfire too for reference?) looking forward to your upcoming videos.

I enjoy all you videos. Well done. PS, your Wright brothers stuff is great.

There are many WWII vets who talk about out-turning an ME-109 under the right circumstances - altitude, speed, etc. Often they would drop some flaps that that would enable them to turn inside the ME-109

Please by all means quote Clarence Anderson, Colonel Bud is a one and only. I hope that one day they declassify his wild weasel strategies and let us see the camera footage. I just poured a shot of Old Crow.

Awesome video and funny at moments...such as at 2:08 where you stated that our parents had paid for that book long ago...awesome!

Have you ever looked at P-51 V Navy F-6-F...though it seems like there are many variables...excellent videos.

Thanks Greg!

Good stuff, as usual.

Good stuff as always!

Great vid, got itself a sub

this reminds me of the book i read about john 40 sec boyd and his energy management theory and how it applied to fighters. well done sir.

The A36 was a Mustang optimized for ground attack.

The first "Mustang" image was an A-36 Apache dive bomber.

It should be noted that RAF and RN Spitfire/Seafire pilots used the Franks water filled G-suit as early as 1942. I've read that they exceeded the structural limits of the Seafire and returned with bent and wrinkled wings. That was Op Torch, so I'll assume it was low level combat.

I'd like to see the second part of this subject on sustained turn performance. And a third one that lists the various turn rates both instantaneous ans sustained at various speeds and altitudes, for all the major aircraft types in use in WW-II, but I think that is probably too much to ask? As all ways, I love your stuff.

I would like to see a video comparing specs on the p51b & c models to the p51d. Most people don't even know these older models exist. Great video!!

Very good commentary on warbirds. Not borring at all. Keep them coming.

It was an A36 in the start if the gun placement is still a dead give-away.

Would you do a comparison of the Sabre and the Mig-15 turn radius?

An additional factor is pitch trim, Airfoils have a (generally) nose down pitching moment that is balanced by the horizontal tail. The tail load is adds to the load already born by the wing as it pulls the plane thru the turn... more induced drag. The Mustang’s airfoil has appreciable pitching moment; the Wildcat’s NACA 23015 has nil. The NACA 230xx series nil pitching moment meant the pilot could throw the plane around without having to trim. The 230xx was used on the Wildcat, Hellcat, Bearcat, Corsair, Lightning, FW190 and Beech Bonanza... it’s been around. Downsides is bad stall, drag, and won’t carry ice.

Interesting subject. After watching a video of a Wildcat flying a vertical S, I decided to try it in my Extra 330LC. It gets even more intricate when you consider the dynamics of changing gravitational effect in a vertical S. The Wildcat stacked a half loop on top of an Immelmann. In the Extra, it is possible to stack two Immelmanns (only just). I determined that an Immelmann is possible if you start at 100 KIAS, but you are very low on energy in the roll-off-the-top (around 40 KIAS, unloaded, but with significant torque and propeller slipstream effects due to the low speed and loss of aileron effectiveness). You cannot pull more than 2.5g on the entry, or you will enter an accelerated stall that will rob energy and make it impossible to continue. This means the first (lower) Immelmann must leave you with at least 100 KIAS on its exit to facilitate an immediate second Immelmann. It can be achieved by starting the first Immelmann at around 175-185 KIAS and pulling around 6-7g initially. This will leave 100-120 KIAS available at the start of the second Immelmann. Now to figure out the optimum g to maximize energy retention and attempt to improve the symmetry of the figure (since the top Immelmann is much slower, but occurs at significantly lower g, it is hard to estimate the radius of turn for each). 1g stall in my Extra comes at around 63 KIAS (two up), so 185 KIAS will accommodate an instantaneous 8.5g. G-limit two up is +/-8g, but solo it goes up to +/-10g. I estimate that solo I can run about 15% lighter, which should improve the vertical performance, although inertia may actually be beneficial in the initial “zoom.” The difficulty is optimizing g-loading to maximize performance (high g means you turn tighter (initially), but it significantly increases induced drag and robs energy). A tighter turn radius also reduces the time you spend fighting the Earth’s gravity opposing your thrust. All the quantities are continuously varying, making for some very complicated physics.

Thank you for a great video. Not a pilot but I have flown and my most memorable experience was in a t-34 when we rolled 90, no back stick, and Dropped Like a Rock intentionally, no rudder, as to be expected. Is top rudder used in these high bank angle steep turns? Thanks.

This is super interesting video. Also that plane in the beginning, I thought it looked weird to be P51 but thought I was mistaken lol I can't really pinpoint any differences but it looks odd to me(and yeah after reading the comments I found out it was A36)

awesome video

Great videos! I had to laugh when you mentioned one plane absolutely out-turning the other "and vice-versa". Years ago I read a commentary on Zeroes and P-40s. It may have been Murray Rubenstein's excellent comparison series, but I really don't remember for sure. What I do recall is reading a quote from a P-40 pilot to the effect that "I never met a Zero that could out-turn me." Given that pretty much everyone agrees that the Zero was by far the better turner, I learned a little bit about how much perceptions play a part in what we see. If a P-40 pilot takes a shot from 300 yards behind a Zero and the Japanese pilot throws it into a tight turn in an attempt to avoid another shot, the American only has to turn a few degrees to keep him in his sights. Sure, the shot's going to be a much worse deflection shot, but as far the shooter is concerned the Zero is still in front of his guns and it sure looks to him like he easily out-turned his target. Of course personal experience is one of the worst judges of facts, but I can see where a lot of these stories get their start.

The FM-2 vs. P-51 comparisons are really cool. Where else but on Greg's channel would you see that?

Hi Greg. Would it be a available for you to do a video on the reason for the different positions of the horizontal stab. Example, why are the P-51 and zero hor. stabs forward of where the F4F wildcats are. I would have thought the further back the horizontal Stabilizer and elevator, example, the F-22 Raptor, the more mechanical force generated to point the nose. Thanks again for your videos, love the educational value.

Interesting video series. While the P51 mustang is my favorite aircraft of all time it's interesting to see a proper analysis to see how much what I know or think I know is just myth and bull shit. To be honest I think timing of the mustang introduction plays a huge part in it's success in Europe but to win air superiority over a foreign country is a huge victory. The germans out numbered the RAF 6:1 and lost the battle of Britain and they had airfields in France the Americans did it from England for the most part. Home ground advantage is a big force multiplier. I'll be watching your series to learn more. keep up the good work and thank you.

these videos are really interesting! especially if you only have flight simulator experience :D

This is a great channel. Im only an Arm Chair pilot but I think comparing a p51 turn radius to a bf109's would be like comparing Ford Mustang super snake to a Lotus Exige S. you can Tell every bit of the Bf-109 was made for turning. Even Roll rate, Which I don't even think can be compared... x6 50.cal Machine guns plus amo hanging out in the wings, plus over 2,000 lbs heavier. As you said Turn rate may be close though. but if I think of roll rate+ turn rate +climb rate id say My money is on the bf-109.

5:00 that explains a heck of a lot about the P-38 being so surprisingly agile, honestly. It was a poor sustained turner, but in the right conditions, it could hold with Zekes for a brief moment

The first North American aircraft was an A-36 Apache, the duve bomber conversion of the P-51 A.

You mentioned doing a P-51 vs. turn FW-190D comparative. PLEASE DO THIS!! The world has an aching need to know.

Why does everyone forget about the P-38? The P-38 was the only WWII fighter with Fowler flaps that provided lower stall speed in addition to drag. With one notch of flaps, a P-38 J model had a power on stall speed below 60 knots. The aircraft had a notch on the flap level that allowed the pilot to ''slap' the flaps to this setting. This gave it the tightest turn radius of any American or European fighter. Only the Zeek and Oscar could out turn it. You don't hear about this much because American doctrine was boom and zoom rather than turn and burn.

I've read other places that the turn performance of a P-61 was better than any other fighter of WWII. I haven't watched much of the video above but it sounds like you're concentrating on those 2 aircraft. I was hoping for a more widespread comparison of various craft in a typical war time load for comparison. I watched a Navy F-14 at the Point Mugu Space Fair (their name for their annual air show) do a full 360 degree turn while about 250 feet above sea level within the confines of the base between the outer fence and the runway closest to that fence, where the pilot basically stood the plane at nearly 90 degrees from horizontal and flew that circle and I could hear the jockeying of the throttle and see the shifts in the control surfaces as he flew the circle. I doubt seriously if any WWII fighter could have matched that circle under any circumstances. That pilot certainly earned his pay that day.

i live in belgium;, we use metric. i had to convert everything to metric. wich is pretty time consuming;, yet i foiund it an informative and fun video :) greetz from Belgium :)

I was talking to an old FM-2 pilot at an airshow years ago. He said that the FM-2 was way better than a wildcat. It had a lot more real world power and was very maneuverable. He said that they had no problem with zeros. In a turning fight he said the FM-2 could eat any other airplane alive

This month's Flight Journal has an informative article on the A36 Apache.

Any more on this topic? Cant believe i only saw it now. Was a good listen.

Great video. I do believe that the "mustang" you first showed was an A-26 Apache.

Fascinating

Did I hear right? Is stall speed higher when the engine is running? If so, is this because you need aerodynamical force to counteract the torque from the engine; or because the propeller disturbes the airflow over the winngs more, when it is providing power?

I think the first plane you showed may be a P-51A or an early variant. There's an early one on display at EAA here in Wisconsin before the bubble canopy was added. Either way, I love your channel.

I've read in several articles that a 4-engined Short Stirling bomber could and did out-turn a Bf109. I find that a bit incredible (in correct parlance, not modern parlance).

Rate should be part of this title, discussion as well( it is later in the video) , as it isn't just turn radius, it's rate in terms of degrees per second which determine turn performance overall, many new flyers don't figure this out initially.

Ah.. that "not a P-51" at the beginning of the video is the A-36 (officially "Apache") displayed at the Wright Patterson AFB museum at Dayton. I must've visited it 3 or 4 times over the years. The dive flaps are down and you can see the yellow identification stripe painted under (and I think over) the wings, because it resembled a Me-109 in the air. For those who haven't come across the A36 - it's the dive bomber version of what became the P-51, with the Allison V-1710. These were the first "Mustangs" used by the USAAF, mainly in Italy. Lots of people seem to have the opinion that the Allison Mustang was a lousy fighter - this is very far from the truth. It was faster than anything else available at the time on the deck, and the British made good use of it starting in late 1942. IIRC they only lost one to enemy fighters, while it was fully capable of engaging and shooting down Me-109s and FW-190s at the altitudes it was used at (mainly for rhubarbs and low level reconnaissance).

@ Greg - Any likelihood of a video comparing the characteristics, strengths and weaknesses, ballistics, etc., of the most commonly used WW 2 aircraft armament? Or is that a possible WW3 "starter"?

4:45 -- I feel like you and I are on the same metaphorical page at many points during this discussion. At the top of the video, you noted that there's two issues at hand: (a) minimum turning radius, and (b) maximum turning rate. And at that time, I said to myself -- that's not tough to keep separated! (A) will be a function of SPEED, whereas (B) will be a function of ACCELERATION (which we'll be calling thrust, or available power). Yay, high school physics and maths. :D

Great series, engineering meets wwii trivia I wonder if you could do a homework assignment. You seem to have the background to sort it out My dad flew in the USNR in WWII. He spent time in F4s, F6s, F8s, and F4Us. He loved the F6 and was always a bit fearful of flat spins in the F4U Could you look at how good or bad the Corsair really was? Thank you.

Done anything with the P-38?

With the laminar flow wing the p-51s maneuverability was improved at around 400 kmh. And was a brick at lower speeds. The saber had the same issue so that’s another factor it reduced turbulence on the wings when turning allowing to to maintain speed. And be able to pull tight turns where any other design (like the 109) would loose manuevering performance due to turbulence on the wing root this is unique to the p-51 and what made it so futuristic. I just wanted to contribute this

Do wing slats on 109 offer an advantage? Also, a plane nearly out of fuel ad ammo would be much more nimble

Can you do more on the engine and turn performance of the Zero?

I agree, plane version and pilot skill are very important factors on top of physics. Put Erich Hartman in a 109-K and he's probably outturning every P51 on the planet. Put a rookie in a 109-E and he's probably outturned by every P51 on the planet..

I wish you would write a book and say what you imply. Marcus Russell

If you dropped a few degree of laps, what would that do for a sustained turn. I always wished when they swapping out the motors, they should have added leading edge wing slats to the stang, maybe bleed a little coolant air over the wing, boundary layer style... why not build a totally new plain? Thanks for the videos, love the detail.

Like you said, power plays a big role here. And thus it depends entirely on which 109 variant and which engine setting the P-51 was running at. The P-51D before June 1944 was limited to only 67"Hg M.P. which equated to about 1630HP at takeoff. However after June 1944 it was cleared for 75"Hg and thus had about 1860HP at takeoff. A Mustang running this setting would out-turn any Gustav or Kurfurst 109, while being still being out-turned by the earlier 109F and E. Of course, this isn't taking into account fuel loads. The P-51Ds often faced 109s with lots of fuel loaded up, so that might have evened the playing field more.

I'm really interested in the dogfight between the Dauntless and the Japanese Zeros. The way I heard it (a video) was that the Dauntless pilot would slip his plane sideways countering the Zero's famous maneuverability. More than a few Japanese planes were shot down, but because the Dauntless pilot was making such radical movements, his tail gunner wasn't able to do much more than hang on and spot planes. I'd really appreciate hearing what you think, knowing it'll be well supported. Also to what degree could WWII fighter planes do these same things, and if so why they didn't do more of it? And of course, what better informed questions should be asked about this? Thanks.

Walter Eichhorn, a well known German pilot who flew the Messerschmitt "red 7" and participated in the filming of "Memphis Belle", later told me very much the same during a dinner. Furthermore in his opinion a Bf 109 G-10/K-4 was capable of outturning a P-51 D without difficulty (Eichhorn flew both types).

Can you make a video about P51d disadvantages. Everybody talking only about P51d superiority, but there is got to be also some bad things. Could this aircraft compete with germans fighter in low/mid atitudes? Wasnt P51d also very vulnerable if it was hit in belly, because it didnt have strong protection?...

Why did the P-51D have the characteristic kink at the inner part of the wings, and why was this omitted for the later P-51H?

Everyone knows those History Channel dogfight tv series. I remember the story of a long, climbing diving contest involving a Corsair. A technical analysis and explanation behind this kind of story would be interesting to hear.

Very informative video. What you must remember is that air superiority is a contest between complete air combat systems. You need to compare all aspects of the machines and weapons as well as pilot training and logistics support. Pilot training is also crucial and the Allies, especially the US had the ability to rotate skilled combat pilots back as instructors and also to give the pilots the necessary hours to be far more skilled than new Axis pilots. Also, remember that the US bombers while suffering horrible loses also inflicted massive losses on the German fighters. And the Allied offensives against German fuel resources greatly cut the ability of Germany in their attempts to train new pilots. It is even necessary to consider cultures, with the US men's experience bird hunting with shotguns they were ideally suited to learning high deflection shooting. Also, the men from the US had far more experience repairing engines since the farm equipment and far more cars in the US meant there was a ready supply of experienced mechanics. And then there are just the fortunes of fate with the US having the M2 Browning .50 calibre which was by far the best air to air weapon of the war. While it was not the heaviest calibre its flat trajectory and high cyclic rate meant it was probably the easiest air to air weapon to become proficient with and its varied ammo made it very effective against German planes without self-sealing fuel tanks when firing incendiary rounds. While the Germans produced large numbers of aircraft they simply had no hope of matching the US war production with the US outproducing the rest of the world by large margins of aeroplanes and virtually all other weapons. The US also trained the Russians on mass production so they could also produce a large number of tanks and planes as well. Had the Army Air Corp adopted the Pacific Naval aviation training for aviation marksmanship the Allies would have really devastated the German Air Force. The Pacific Naval Aviators were by far the best trained and best marksman of the world's aviators during the war. The Naval Aviators often practised marksmanship every other day when cruising with two carriers. One carrier provided CAP and sub patrols while the other practised high deflection shooting with towed targets and then alternated the next day. The Pacific aviators were the first to jury-rig deflection sights from Army bombers to aid them in high deflection shooting.

Many P-38 pilots found that at lower altitudes in a turn against a 109 you add power to the up-wing engine, reduce power to the down-wing engine, and open the Fowler flaps about 10 degrees. You cut right inside of him where those 4 50 cals and single 20mm cannon cut him in half like a rip saw through balsa wood. Just ask Robin Olds. He loved his P-51 but understood the capabilities of his P-38 and pretty much every aircraft he flew. I think pilot skill is the best determining factor in turn radius.

One more point. Turn radius or pretty much any turn ability can be negated with the right tactics. Claire Chenault's P-40s were slower than Zeros, could not turn or climb with Zeros and they shot down scads of zeros by attacking from a higher altitude and zoomed through the Zero formation much faster than the zeros could dive and then continue their dive and pull a zoom climb out away from the conflict and return again from higher altitude to do it again, and again etc.

Sir would you please give me the links of the source materials you have used to make this video?

That's fascinating. I can't believe many Navy fighters were ever flown to Angels 30, since they didn't escort many B-29s, and few Japanese planes could reach such a high altitude.

The aircraft in the early shot could be a P51; specifically, it could be an -A model, except for the dive brakes, which make it an A-36.

One critical thing was omitted in this video: maximal lift coefficient CLmax depends on Mach number, so, if it is derived from 1g stall speed with low Mach, it is not suitable to calculate high speed and high-g turn performance. The difference for unswept wings are very noticeable, for example, for P-51 only 80-75% of the low Mach CLmax remains at 0.5-0.6M. P-51 airfoil is very special - it has no constant CLmax drop with Mach number, but other conventional airfoils for P-39, F-6F, etc have very sufficient CLmax drop up to half of initial. At high altitude this effect is even more noticeable because of low EAS, high TAS and lower speed of sound. For GA planes with low Vne/Vstall ratio this 1 g stall approach is widely used without significant errors, but it is unsuitable for high-performance fighters.

Like Erich Hartmann said, you cannot say this or that Airplane was better. It really depended what Pilot sat in them. And I heard that the ME 109 K4 was faster than the P-51. But I cannot really confirm if this is the case.

A-36 ground attacker, nose gun and razor back make it easy to distinguish

Very interesting stuff. One thing that has me thinking would be more powerplant changes in aircraft. What made the Mustang the Mustang was the Spit's engine. It turned it from a decent aircraft into a high altitude beast that was also pretty fuel miserly and just very good overall in a fight. I would think there'd be no way for a Mustang to outturn a Spit due to Spit's near glider like wings. Both those wings, the Mustang's and the Spitfire's may be the most famous fighter wing designs of the war. One is as thin as it can be but is still deep because it holds a 20mm cannon. The other embraces laminar flow design that had its own neat effects. All of that gets a person to wondering what some aircraft would be like with the engine of another. Can you imagine a snub-nosed Mustang or Spit with a PW R-2800?

Ive seen P51s pulling 16 second turns for a second or two in other sims... but in WT its certainly NOT a turner, however, at a decent speed, it really can turn!

Can you explain what wing-loading means?