F4U in Europe

[Howard Gibson]

Correct. A Seafire III was included I believe, but it was something of an afterthought. Would be a little worse performing than a Mk.V, but the turn rates would be similar I think

This is what David Brown wrote about. The Hellcat out-turned the Seafire. The LIIIC Seafire was faster below 9,000ft. It had a faster roll, it was very much superior in acceleration and rate of climb. The Hellcat was faster above 10,000ft, it had a longer range. It was sturdier, and way safer to land on a carrier.

 

[Clayton Magnet]

This is what David Brown wrote about

Was this posted earlier in the thread? Perhaps I missed it

 

[Howard Gibson]

Was this posted earlier in the thread? Perhaps I missed it

Yes, by me.

 

[pbehn]

I understand that the control surfaces utilized during the implementation of a coordinated turn are the ailerons, rudder, and elevators. Maybe we can look further on the effectiveness of these in regards to both the Hellcat and Spitfire and draw some conclusions???

Hopefully real world pilots such as BiffF15 and FlyboyJ can also chime in and tell us what their thoughts are in regards to what factors can effect turn performance such as control surface design, wing loading, engine/propeller torque, location of CG, ect, not to mention altitude and speed at which the turn is initiated.

Any aircraft engineers or aerodynamicists out there as well?

As I understand it, instantaneous turn depends on things like wing loading and strength, the difference between how much power (thrust) the plane has and how much drag it generates determines how quickly it spirals down maintaining a that high G turn. For turning at a sustained altitude this can be compared to rate of climb. Maximum rates of climb and rates of climb at given forward speeds and altitudes are indicators of sustained turn ability at those altitudes and speeds. I would not be surprised if a Hellcat could out turn a Spitfire in instantaneous or low speed descending turns, a Hurricane could too. But carrier aircraft are normally at quite low altitude you cant lose altitude turning for long before you hit water.

If that makes any sense at all?

 

[Clayton Magnet]

I have David Brown's book on Seafires here. A Seafire is a modified, albeit, heavier version of the Spitfire MkV. Brown claims that an experienced pilot in an F4U or F6F could out-turn a Seafire.

Do you have the reference handy? An experienced pilot in a Corsair or Hellcat may very well pull harder, because they know the limits of their aircraft. An experienced Hellcat pilot could out turn an A6M as well, if he kept his speed up and didn't play the Zero's game.
Oberleutnant Erwin Leykauf claimed that he could ALWAYS out turn a spitfire in his Bf 109E, and often did, because he knew exactly where the stall was after the slats popped out, and could hold it there expertly. The pilots he out turned most likely didn't have his skill and experience, and didn't get the most out of their machine. Doesn't mean the 109E had a smaller turn radius than a Mk.I Spitfire, just means he knew what he was doing. A Spitfire Mk.V has a significant wing loading advantage over both the F6F and F4U, and should have a correspondingly smaller minimum turn radius.

 

[pbehn]

I have David Brown's book on Seafires here. A Seafire is a modified, albeit, heavier version of the Spitfire MkV. Brown claims that an experienced pilot in an F4U or F6F could out-turn a Seafire.

There were many types of Seafire, the most produced was based on a MK V Spitfire but a Mk V Spitfire was also the most produced Spitfire, the later versions of it were real low level hot rods, lighter than the twin stage types like the MK IX but with the same power if using the same boost and fuel.

 

[Howard Gibson]

Do you have the reference handy? An experienced pilot in a Corsair or Hellcat may very well pull harder, because they know the limits of their aircraft. An experienced Hellcat pilot could out turn an A6M as well, if he kept his speed up and didn't play the Zero's game.
Oberleutnant Erwin Leykauf claimed that he could ALWAYS out turn a spitfire in his Bf 109E, and often did, because he knew exactly where the stall was after the slats popped out, and could hold it there expertly. The pilots he out turned most likely didn't have his skill and experience, and didn't get the most out of their machine. Doesn't mean the 109E had a smaller turn radius than a Mk.I Spitfire, just means he knew what he was doing. A Spitfire Mk.V has a significant wing loading advantage over both the F6F and F4U, and should have a correspondingly smaller minimum turn radius.

The Seafire, by David Brown.

The tested aircraft was a Seafire LFIIIC, which had clipped wingtips. The low altitude Seafires were hot rods, although only at low altitude. The LFIICs and LFIIICs had six stack exhausts and, four blade propellers, so they look a bit like Spitfire_IXs. The engines put out 1,600HP at low altitude.

All of the WWII Seafires were modified Spitfire_Vs. The post war XVs and XVII were like Spitfire_XIIs, Seafires with Griffon engines replacing the Merlins. The Seafire_45 was the first to get a two-stage supercharger.

I have recently learned that the flying Seafire_47 with the six blade contra-rotating propellers is using a Griffon_57 engine, presumably from an Avro Shackleton. Single-stage supercharger.

 

[FLYBOYJ]

I understand that the control surfaces utilized during the implementation of a coordinated turn are the ailerons, rudder, and elevators. Maybe we can look further on the effectiveness of these in regards to both the Hellcat and Spitfire and draw some conclusions???

Hopefully real world pilots such as BiffF15 and FlyboyJ can also chime in and tell us what their thoughts are in regards to what factors can effect turn performance such as control surface design, wing loading, engine/propeller torque, location of CG, ect, not to mention altitude and speed at which the turn is initiated.

Any aircraft engineers or aerodynamicists out there as well?

Aside from wing loading and performing a coordinated turn (pilot skill) you have to look at lift coefficient and available thrust. I had this link bookmarked, I think this explains a lot while discussing formation flying. https://www.kimerius.com/app/download/5784133491/Fighter+formation+fundamentals.pdf

 

[DarrenW]

Aside from wing loading and performing a coordinated turn (pilot skill) you have to look at lift coefficient and available thrust. I had this link bookmarked, I think this explains a lot while discussing formation flying. https://www.kimerius.com/app/download/5784133491/Fighter+formation+fundamentals.pdf

I totally forgot about the importance of lift coefficient.

And thank you for the link. I will read it over and see what I can further learn about the topic.

 

[DarrenW]

After re-discovering the importance of lift coefficient (CL) in a turning maneuver, I went back to look at some calculations presented by Francis H. Dean in his book America's Hundred-Thousand. On page 603 he created a chart which showed the turning performance of various fighters, including the Hellcat. He devised a rating system which utilized the formula:

wing loading/maximum lift coefficient=minimum turn radius index

In a nutshell, the aircraft with the lower index rating will be capable of a tighter minimum turn radius. I was then able to locate documents created by NACA during the war which show the results of stall testing performed on both the Spitfire Mk. VA and F6F-3 airplanes:

http://www.wwiiaircraftperformance.org/NACA-Spitfire-V-Stalling.pdf (page 7)

https://ntrs.nasa.gov/api/citations/19930092602/downloads/19930092602.pdf (page 3 &4)

I then used the minimum turn radius index formula and plugged in data from these reports and came up with these figures:

Spitfire Mk.VA : Glide condition (gear up/flaps up/no power) = 22.3
landing approach (gear down/flaps down/2300 rpm) = 14.9

F6F-3 Hellcat: Glide condition (gear up/flaps up/no power) = 23.1
landing approach (gear down/flaps down/2550 rpm) = 13.7

For reference purposes, the Hellcat was tested at 11,200 lbs, which put the wing loading at 33.5 pounds per square foot, while the Spitfire was tested at 6,184 lbs giving it a wing loading of 25.6 pounds per square foot. Both aircraft were apparently flown below their maximum take-off weights. I decided to use lift coefficient data with gun ports open, as I felt this better represented a combat condition airplane. By the way, the Spitfire test weight was obtained from a NACA report which was created during the same month as the stall testing of the airplane (September 1942), so I can only assume that the test weight for each was the same.

http://www.wwiiaircraftperformance.org/NACA-Spitfire-V-Flying.pdf

What I can gather from all of this is that the Spitfire has a slight turn advantage in a glide condition but when in a landing condition the Hellcat edges it out to some degree. I think the Hellcat benefited from a more efficient flap design, allowing for a much higher lift coefficient in a landing condition. I am aware that Hellcat pilots would sometimes deploy flaps in a dogfight in order to tighten their turns. It is also interesting how close the two aircraft are while using Dean's method to determine turn performance.

What do you guys think of all this? I know it's not the most scientific means of determining turn radius but to some degree it does make sense, at least to me.

 

[Thumpalumpacus]

What do you guys think of all this? I know it's not the most scientific means of determining turn radius but to some degree it does make sense, at least to me.

It may or may not be definitive -- I'm not qualified to say one way or the other --but I sure do admire you shaking this problem like a terrier shaking a rat, and appreciate you doing so.

 

[DarrenW]

It may or may not be definitive -- I'm not qualified to say one way or the other --but I sure do admire you shaking this problem like a terrier shaking a rat, and appreciate you doing so.

LOL It is crazy how much effort I can put into something that most human beings would find a complete waste of their time! But I find it extremely fun so why the heck not?!?

 

[Thumpalumpacus]

LOL It is crazy how much effort I can put into something that most human beings would find a complete waste of their time! But I find it extremely fun so why the heck not?!?

I get that way about things at times ... I had a friend way back when who'd tell folks, "watch out, Darrell's got lockmind right now."

 

[Clayton Magnet]

Now that's really going into the weeds! , thanks DarrenW .
I am going to quote the late, great Parsifal here, whom had forgotten more about this stuff than I will ever know. I hope he wouldn't mind me using his words.

"Hellcat turn radius at its optimum combat speeds was about 670 feet. optimum turn radius for a spitfire @ 12000 feet and at sustained speeds in excess of 300 mph was 676 ft. On the face of it, the Hellcat can out turn a spitfire (by about a smidgeon), but we are not comparing apples to apples here. The speeds art which the Spitfire is making that turn are significantly greater than for Hellcat. If you compare the turn radius at similar speeds, the Spitfire will out turn the Hellcat by a comfortable margin.

RAAF tests conducted in 1943 after the drubbing it received at the hands of the A6M3 revealed that at lower speeds, the Zeke could easily out turn the Spit, but at higher speeds the tables were turned and the Spit could sustain a turn rate equal to or better than the Zeke. this was never matched by the Hellcat, except at speeds that the Zeke couldnt even be flown at.

There is no question in my mind, the Spitfire was a more manouverable plane in the horizontal plane."

Taken from this thread Hellcat vs Spitfire - which would you take?

 

[Clayton Magnet]

We know from the Navy trials with the captured Ki-61, that the Wildcat Fm-2 and Tony were "approximately equal in turn radius at all altitudes" . That same trial rated the Ki-61 as "greatly superior to the F6F in turns", so I think one could reasonably conclude that the Wildcat could comfortably turn inside a Hellcat. My question now, is there a comparative trial between a Seafire/Spitfire and the Martlet/Wildcat?

 

[DarrenW]

Now that's really going into the weeds! , thanks DarrenW .
I am going to quote the late, great Parsifal here, whom had forgotten more about this stuff than I will ever know. I hope he wouldn't mind me using his words.

"Hellcat turn radius at its optimum combat speeds was about 670 feet. optimum turn radius for a spitfire @ 12000 feet and at sustained speeds in excess of 300 mph was 676 ft. On the face of it, the Hellcat can out turn a spitfire (by about a smidgeon), but we are not comparing apples to apples here. The speeds art which the Spitfire is making that turn are significantly greater than for Hellcat. If you compare the turn radius at similar speeds, the Spitfire will out turn the Hellcat by a comfortable margin.

RAAF tests conducted in 1943 after the drubbing it received at the hands of the A6M3 revealed that at lower speeds, the Zeke could easily out turn the Spit, but at higher speeds the tables were turned and the Spit could sustain a turn rate equal to or better than the Zeke. this was never matched by the Hellcat, except at speeds that the Zeke couldnt even be flown at.

There is no question in my mind, the Spitfire was a more manouverable plane in the horizontal plane."

Taken from this thread Hellcat vs Spitfire - which would you take

No problem Clayton...looks like you like getting dirty too lol!

What Parsifal said is basically proven out by my previous post. The Hellcat could normally out-turn the Spitfire at low to medium speeds but anything above 200 mph the Spitfire reigns supreme. How did I come up with this number? Well the Hellcat has an automatic electric flap system which could only be utilized below 170 knots, or 196 mph. This was implemented as both a safety feature as well as to lessen the workload of the pilot. Just flip the flap switch and the flaps will only work at pre-determined speeds. Once deployed, the flaps "blow up automatically" at varying degrees once 90 knots is reached, per the pilot manual.

So I think we now know the circumstances as to why David Brown made the statement that he made, agreed?

 

[DarrenW]

We know from the Navy trials with the captured Ki-61, that the Wildcat Fm-2 and Tony were "approximately equal in turn radius at all altitudes" . That same trial rated the Ki-61 as "greatly superior to the F6F in turns", so I think one could reasonably conclude that the Wildcat could comfortably turn inside a Hellcat. My question now, is there a comparative trial between a Seafire/Spitfire and the Martlet/Wildcat?

So are you comfortable saying that the Hellcat has a turn performance "greatly superior" to the Corsair? According to the graph it sure looks that way. My gut feeling says NO.....

 

[Clayton Magnet]

What Parsifal said is basically proven out by my previous post. The Hellcat could normally out-turn the Spitfire at low to medium speeds but anything above 200 mph the Spitfire reigns supreme.

I think Parsifal stated the opposite. The Hellcat turning at its optimum speed was about equivalent and slightly better than a Spitfire (Which mark?) turning at 300+mph. When both are turning at the same, lower speed, the Spitfire turns inside the Hellcat.

Basically, if a Hellcat is going to out turn a spitfire, the Hellcat needs to be going slow, and the spitfire needs to be going fast. Same way the spitfires were able to out turn the A6M3's as per the RAAF test

 

[Clayton Magnet]

So are you comfortable saying that the Hellcat has a turn performance "greatly superior" to the Corsair? According to the graph it sure looks that way. My gut feeling says NO.....

I don't think so, looking at that graph, they have the F6F only slightly in front of the F4U-4. I would be comfortable saying the Hellcat was a good turning fighter, but only really when compared to other heavy weights, like the F4U, P-47, P-51 and Tempest.

 

[Schweik]

How much does lift coefficient vary between Spit, F6F, F4U, Bf 109, P-51 etc.? How much of a difference does it typically make compared to Wing Loading?

The Soviets always made a significant distinction between 'horizontal' (turns) and vertical (loops etc.) maneuvering, and rated aircraft according to these factors. The latter has to do with climb rate.

Every anecdotal account I know of, and every test seems to place the Spitfire V, VIII or IX as a superior turner to almost any other aircraft it was compared to, with the exception of the A6M and Ki-43, and as previously noted here Spitfire (like several other Allied types) could out-turn A6M in high-speed turns. Not sure about the Ki-43 on that specific.

The issue of using flaps in turns is significant of course. Many aircraft had maneuvering flap settings, like Bf 109s I believe did, some had automatic maneuvering flaps like the Ki-43 and N1K1. From what I understand, most US Navy aircraft including specifically F4F and F6F, had flaps which could not be deployed above a certain speed, and which would automatically close. The Spitfire also seemed to have only two flap settings from what I remember reading - basically landing or up. They seemed to have such a turning advantage over German fighters that a combat flap setting wasn't thought necessary. The preferred strategy for dealing with Japanese fighters also tended against trying to improve turn rate.

The other factor in turns is power, which you can measure in power to weight ratios.

I was surprised to learn how relatively poor the roll rate for the F6F was. I always had a pet theory that most really successful fighters had pretty good roll. Maybe I need to rethink that.

Here are 'standard*' wing loadings and power / mass ratios for several fighters under discussion. Obviously this is very 'back of the envelope', it's just meant a kind of quick reference.

Fighter ------ Weight*----- Wing Area ---- Wing Loading ---- Horsepower --- Power Loading ---- Full throttle height (Not certain about these numbers)
F6F-3 -------- 12,500 ---------- 334 ----------- 37.4 --------------- 2000 ----------- 0.16 ------------------ 22k
F4U-1 ------- 12,000 --------- 314 ----------- 38.2 --------------- 2000 ----------- 0.17 ----------------- 22k
Spit V -------- 6,400 ---------- 242 ----------- 26.4 --------------- 1478 ----------- 0.23 ----------------- 20k
Spit V (Clipped)6,400 -------- 231 ------------ 27.7 -------------- 1478 ------------ 0.23 ----------------- 18k
Spit IX -------- 7,200 ---------- 242 ----------- 29.7 --------------- 1600 ------------ 0.22 ----------------- 25k (and 14k)
P-51C --------- 9,000 ---------- 235 ----------- 38.2 --------------- 1490 ----------- 0.16 ----------------- 25k
P-51D --------- 9,500 ---------- 235 ----------- 40.4 --------------- 1560 ----------- 0.16 ----------------- 25k
BF109G2 ------ 6371 ---------- 177 ----------- 35.9 --------------- 1450 ------------ 0.22 ----------------- 22k
Bf109G6 ------ 6940 ---------- 177 ----------- 39.2 --------------- 1550** ---------- 0.22 ----------------- 25k

* for weight I put combat weights I found on WW2Aircraft performance. This is supposed to be 'normal combat weight' not max gross.
Mustang on wing area I saw 233 or 235, I'm not sure which is right.

** G-6 has 1800 hp under MW/50 boost from what I understand, which makes power-weight of 0.25

Clipped wing Spitfires seem to have only marginally heavier wing loading but anecdotally, they didn't turn as well from what I understand.