The one most over-rated plane of WWII

[Shortround6]

All good but remember - just because you have "volume" doesn't mean it can be filled without structural modification. Say you can put fuel tanks in the leading leading edges, what's going to happen to that wing under g loads? Heavier more powerful engines means more torque and more loads to the airframe. Strengthening will be required = more weight, but I think you know all this.

I quite agree, but if you don't have the volume in the first place????
P-47N wing? Add wing root and then clip wing tips. Structural changes/strengthening?

P-38 Put intercoolers in the engine nacelle, use wing leading edge for fuel. 55 gallons of fuel in the outer wing leading edge is going to need some beefing up and recalculation but it beats having no volume to stick the fuel.

 

[pbehn]

I only discovered recently that 100-octane fuel might not have happened in time had it not been for some people who pushed against the conventional wisdom of the day:

How High-Octane Gasoline Saved Untold Allied Pilots During WWII

Aviation legend Jimmy Doolittle pioneered a type of gas that made Allied planes faster and more lethal, helping us win battles and the war.

sofrep.com

Fate often plays a part. Henry Tizard of the Tizard Mission to USA and the British aeronautical research committee was previously reader in Chemical Thermodynamics at Oxford where his work on Toluene numbers led to the Octane rating system itself. Henry Tizard - Wikipedia


There are two issues, one is the performance of engines with 100 Octane fuel, reliability etc. The other is producing it in huge volume with all engines being able to run all fuels.

 

[Shortround6]

Higher octane/performance number fuel was coming, it was a question of when.
Howard Hughes set a speed record in 1935 using 100 octane fuel. At the time it cost about 10 times what regular aviation fuel did per gallon so until the "production" problem was solved it remained more of goal than a factor in operations.

 

[Mike Williams]

Higher octane/performance number fuel was coming, it was a question of when.
Howard Hughes set a speed record in 1935 using 100 octane fuel. At the time it cost about 10 times what regular aviation fuel did per gallon so until the "production" problem was solved it remained more of goal than a factor in operations.

Any idea when the US Army and/or Navy went over to 100 octane?

 

[GrauGeist]

The USAAC established 100 Octane as their standard in 1937, the USN followed shortly after.

 

[Thumpalumpacus]

The USAAC established 100 Octane as their standard in 1937, the USN followed shortly after.

I remember in reading Gen Doolittle's memoirs that he played a part in 100-O fuel development while he was a rep for Shell.

 

[GrauGeist]

I remember in reading Gen Doolittle's memoirs that he played a part in 100-O fuel while he was a rep for Shell.

He was, indeed.
His degree in aeronautics coupled with his racing experience gave him a great deal of insight.

Doolittle was quite forward thinking in many respects and he wasn't afraid to "rock the boat" in order to get things done, too - it's interesting to think how the course of events during the 30's and 40's would have played out if he wasn't there.

 

[Thumpalumpacus]

He was, indeed.
His degree in aeronautics coupled with his racing experience gave him a great deal of insight.

Doolittle was quite forward thinking in many respects and he wasn't afraid to "rock the boat" in order to get things done, too - it's interesting to think how the course of events during the 30's and 40's would have played out if he wasn't there.

IIRC his was the first doctorate of Aero Engineering awarded in America. One of the few guys to survive the GeeBee, too.

 

[Snautzer01]

And a leader that lead per example. Thats is rare in modern times.

 

[MikeMeech]

We would have to define "grow"

The Spit started with a 242 sq ft wing. Fuselage length only grew to the extent of the longer engine/s (and bigger prop hubs) and broader rudder.

More power was certainly added and more armament was fitted and some airframes got more fuel. Gross weight went up considerably but the basic airframe didn't change size.

The Zero got more power and more (or better) guns. Gross weight increased.

Many planes got heavier, very few (if any?) got lighter.

Some planes ran out of room to fit more "stuff" and/or ran out of power or wing area to support more "stuff".
There was a limit to what you could cram into (or under) a 109 or Yak for example.

And yes there a lot of claims about what could have been done with the early Spitfire.
View attachment 648064
That fixed pitch prop has a lot to answer for
Had the Spitfire been designed from the start to use something other than a WW I tech level propeller perhaps they would have done things differently?
But the Spit was not a small as some people imagine. Due to luck/happenstance some of the features allowed for latter upgrades more easily than some other aircraft.

Hi
Best not to get too carried away with the two-bladed prop as only the first 77 built had it, by the start of WW2 Spitfires mainly had three-bladed two pitch props, like the Spitfires, in the image below, at Hornchurch in June 1939:

The Spitfire prototype was used to try out a number of different propeller types according to Jeffrey Quill:

The Rotol constant speed unit was also being tried out by December 1939, although CS units needed the Merlin III fitted to the aircraft:

All info from Morgan and Shacklady.

Mike

 

[pbehn]

Hi
Best not to get too carried away with the two-bladed prop as only the first 77 built had it, by the start of WW2 Spitfires mainly had three-bladed two pitch props, like the Spitfires, in the image below, at Hornchurch in June 1939:
View attachment 648103
The Spitfire prototype was used to try out a number of different propeller types according to Jeffrey Quill:
View attachment 648104
The Rotol constant speed unit was also being tried out by December 1939, although CS units needed the Merlin III fitted to the aircraft:
View attachment 648107
All info from Morgan and Shacklady.

Mike

I know close to nothing about propellers but I would think that the detail of a three bladed two speed or CS prop depends on the actual power of the engine, so every improvement in the Merlin especially the use of 100 Octane fuel would require a change.

 

[Shortround6]

Hi
Best not to get too carried away with the two-bladed prop as only the first 77 built had it, by the start of WW2 Spitfires mainly had three-bladed two pitch props, like the Spitfires, in the image below, at Hornchurch in June 1939:

Not disputing the introduction of the newer propellers but that was 2-3 years after K.5054 first flew so one has to assume that the plane was "designed" to use the fix pitch prop, for good or evil.

see Spitfire Mk I N.3171 Trials Report

for some of the changes in performance the newer propellers could offer, even with 87 octane fuel.

 

[pbehn]

Not disputing the introduction of the newer propellers but that was 2-3 years after K.5054 first flew so one has to assume that the plane was "designed" to use the fix pitch prop, for good or evil.

see Spitfire Mk I N.3171 Trials Report

for some of the changes in performance the newer propellers could offer, even with 87 octane fuel.

The universal shaft for variable and CS props was first put on the Merlin Mk III. So the commitment was there for CS props, but which prop?

 

[nuuumannn]

I'm not claiming that the Zero was a *bad* airplane, but I am saying it was not a *great* airplane.

Perspective counts. The Zero is ranked as one of the Great aeroplanes of WW2. The hype and reputation, which as an American colours your perspective of it changes peoples opinions of it, but the facts about it mean that it was most certainly one of the best aircraft carrier based fighters in the world between 1941 and 1943, if not one of the best fighters in service anywhere.

I'm not a fan of the Zero and never will be, it's not a warplane but instead an armed aerobatics aircraft. Ask yourself a question, would you fly a A6M across the channel in 1940 against chain home or likewise the other way into France in 1941?

No, it was an aircraft carrier based fighter, designed as such and it did what it was designed to do very well indeed. In answer to your proposed question, had the Japanese had a time machine and Zeros replaced Bf 109s, why not? It had cannon armament, it had far better range than the Bf 109 and the defending Spitfires and Hurricanes, it could dogfight as well as, if not better than the other three types and it had good performance, good climb rate etc. As for the crossing the Channel into France in 1941, it was a bad idea at any rate, so the RAF shouldn't have been doing it in the first place; the loss rate of RAF fighters was horrendous.

 

[MikeMeech]

Not disputing the introduction of the newer propellers but that was 2-3 years after K.5054 first flew so one has to assume that the plane was "designed" to use the fix pitch prop, for good or evil.

see Spitfire Mk I N.3171 Trials Report

for some of the changes in performance the newer propellers could offer, even with 87 octane fuel.

Hi
The Spitfire was hardly unusual in the prototype flying with a fixed pitch propeller along with early production examples, the same applied to the Bf 109. The latter prototype flew in 1935 with a RR Kestrel and a fixed pitch prop, the first production examples, Bf 109B went into service (in the Spring of 1937) with JG 132 "Richthofen", although now re-engined, were also fitted with the two-bladed wooden Schwarz fixed pitch prop. The first 109s used in Spain also had these props. Later production Bf 109Bs were fitted with a variable-pitch two-bladed metal VDM-Hamilton prop.
So both Spitfire and Bf 109 were 'designed' to use fixed-pitch props, both types changed to variable-pitch and then constant-speed by 1940, when both were probably the 'best' fighters in the world at that time, I don't see why you appear to believe the Spitfire had some 'unique?' problem for good or evil, later in life due to flying initially with a fixed-pitch prop?

Mike

 

[NTGray]

The Zero is ranked as one of the Great aeroplanes of WW2. . . the facts about it mean that it was most certainly one of the best aircraft carrier based fighters in the world between 1941 and 1943, if not one of the best fighters in service anywhere.

Well, that is exactly what is under discussion here. What do the "facts" actually say? The fact that I think is most important is that in early 1942, when the Zero gained its reputation, the Zero/Wildcat kill ratio favored the Zero by only 1.5 to one, which is not that big an advantage. By the beginning of 1943, after the Americans had learned how to use the Wildcat's advantages effectively, the Zero/Wildcat kill ratio had swung to favor the Wildcat by nearly 6 to 1. This indicates that the superior maneuverability of the Zero (that part is not under question) was not enough to guarantee victory. The Wildcat's advantages (ruggedness, diving speed, a radio), along with superior pilot tactics and training (especially in gunnery) more than outweighed the Zero's advantages.

 

[special ed]

If the Zero & Ki-43 had not been available, there would have little to fight against, hence rapid Pacific war completion.

 

[GrauGeist]

Well, that is exactly what is under discussion here. What do the "facts" actually say? The fact that I think is most important is that in early 1942, when the Zero gained its reputation, the Zero/Wildcat kill ratio favored the Zero by only 1.5 to one, which is not that big an advantage. By the beginning of 1943, after the Americans had learned how to use the Wildcat's advantages effectively, the Zero/Wildcat kill ratio had swung to favor the Wildcat by nearly 6 to 1. This indicates that the superior maneuverability of the Zero (that part is not under question) was not enough to guarantee victory. The Wildcat's advantages (ruggedness, diving speed, a radio), along with superior pilot tactics and training (especially in gunnery) more than outweighed the Zero's advantages.

The A6M was not just fighting American aircraft, so you have to broaden your perspective to get a better focus.

It was engaging a wide range of Allied types with considerable success, and that is where it's status comes from.

 

[R Leonard]

Bearing in mind and in full disclosure, of course, that I am a dyed in the wool F4F booster (wouldn't be here without it) between the A6M2 and the F4F, truth be told, they were probably pretty close to equal with the positive qualities of one canceled out by the positive qualities of the other. Analysis of actions in the first year of the war suggests that F4Fs and A6M2s fought to a standstill with perhaps maybe one more F4F than A6M2 being lost in air to air combat. One can talk all day about the nuts and bolts of speed, wing loading, and what not, but the proof is in the actual air combat arena.

The F4F was marginally slower than the A6M2 at their top ends, but the F4F remained maneuverable at top speed while the A6M2 suffered from frozen ailerons and an inability to roll to the right and an engine cutoff problem under conditions of negative G. These interesting phenomena was noticed in the evaluation of the A6M2 recovered from the Aleutians and was quickly communicated to the VF/VMF squadrons. Two separate, unrelated, Allied evaluations, one in California and the other in China noted these deficiencies.

LCDR Eddie Sanders, XO of Flight Test at NAS Anacostia, was sent to NAS San Diego where he was first to fly the rebuilt A6M2 captured in the Aleutians noting the float type carburetor and specifically in his report of 29 September 1942, "Engine quits on push-overs." Sanders also reported, "Ailerons get very stiff at higher speeds making fast rolls at high speed (above 250 knots) physically impossible. At 200 knots the rate of roll (with ailerons) is slightly slower than an F4F. At lower speeds the Zero probably has an increasing advantage in any rolling maneuvers since it is highly maneuverable."

In China with the 23rd​ Fighter Group, LTC Bruce Holloway, CO of the 23rd​, noted in his flight evaluation of 6 February 1943 with regards to an A6M2 recovered near Teitsan on the
southeastern coast of Luichow Peninsula: ". . . at 300 m.p.h. requires a great deal of force on the controls for even a gentle turn. At these speeds the airplane is very stable, and especially so about the longitudinal axis. It has no tendency to roll in a dive, at 300 m.p.h. it is practically impossible to make it roll," "At speeds above 200 m.p.h. indicated, it is believed impossible to exert enough pressure on the elevators to cause the airplane to stall. This was not actually tried, however, for fear of a structural failure," and "the engine will not run under any conditions of negative acceleration, inverted or in a steep skid. A Zero is unable to follow any airplane which does a sharp pushover unless it rolls and it cannot roll at high speed." Holloway also noted the view over the nose problem, "Visibility is very poor directly ahead and down."

The lessons here were clear. The A6M2 was extremely dangerous in a mid to low speed, turn and burn, type gunfight. The F4F drivers knew that speed was life and, with the USN pilots, almost from the initial encounter at Coral Sea declined to play that game. The USMC F4F pilots only needed a couple of lessons to adopt the same attitude. After the analysis of the captured A6M2 was completed, the word quickly went forth, keep your speed up and do not dogfight with a Zero.

The F4Fs ruggedness was almost legendary. It could, and did, absorb damage that a fraction of which would leave an A6M2 spiraling off in flames. This same ability made the beam defense developed by Jimmie Thach a viable tactic that presented a difficult nut for the A6M2 drivers to crack.

Part of that equation comes from tactics and tactical formations generally. The USN/USMC squadrons operated in two plane sections and four plane divisions. Sections could be internally supportive one with one and externally supportive in divisions, two with two. The Japanese, on the other hand were saddled with the three-plane section, nine-plane division, a practice that looks nice in air shows and was more suitable for WWI type tactics. The 3-9 set up, indeed, evolved during WWI as it provides a better lookout doctrine in the biplane world. The 2-4 set up takes advantage of the monoplane construction with no overhead and forward wing to block the view. While one might think that the greater numbers would work to the Japanese advantage, in practice it was hard to maintain section cohesiveness. Oft times the third man in a section turned out to be the odd man out and it was he who was sure to get burned in an approach on weaving F4Fs. The USN/USMC fighter pilots were already experimenting with, and some squadrons had firmly established, the 2-4 formations before they ever got into the war. The Japanese maintained their 3-9 formations into 1944.

There are other things to consider. The favorite attack from the Japanese was the aft overhead run. The F4F types, having some experience from their per-war training, were well acquainted with the defense for this problem. The defense was the logical extension of their own attack training in deflection gunnery. So, when an attacker starts his run, the F4F driver throws it over to offer only a full deflection shot . . . a tough shot to make without considerable practice, and especially in an A6M2. The position of the cockpit relative to the nose of the A6M2 forced the A6M2 driver, in a full deflection situation (see Holloway's comment), to drop the nose in order to get a sight picture and then raise it in order to fire at a location in space where he expects the F4F to be when the bullets get there. An alert F4F pilot, finding himself on his own with an A6M2 boring in on him and setting up the full deflection problem as his first move, can spot this action. As the nose goes up, the A6M2 guy momentarily loses sight of the F4F, and the F4F breaks off in another direction (preferably down and to the right . . . remember the A6M2 problem with rolling right), leaving the A6M2 firing at nothing. In a defensive weave situation, it gets even worse for the A6M2 guy as the raising of the A6M2 nose to take a full deflection shot at one quarry leaves it completely vulnerable for an underside head-on (and near zero deflection) shot from the F4F approaching from the opposite tact if in a Thach Weave situation. The F4F did not suffer from this design problem. The nose of the plane sloped gently down from the pilot's position in the cockpit, allowing full time observation of an opponent in a full deflection situation.

Armament is another issue. The F4F-3 carried four 50-caliber guns. This seemed to work as advertised at Coral Sea for VF-2 and VF-42. For the most part it was also enough to at least ensure survival for the few USMC F4F-3's at Midway. The F4F-4 was "improved" with folding wings (squadrons went from 18 -3's to 28 -4's) and a battery of six 50-caliber guns. Unfortunately, there was no improvement in the engine, so the added weight of the folding mechanisms and the two extra guns presented a problem. Additionally, the two additional guns resulted in less ammunition per gun, hence less firing time. Some pilots felt quite strongly that the change to six guns did not help the situation. Jimmie Thach remarked that if a pilot was not going to hit with four guns, he certainly was not going to hit with six. So, the F4F-4's performance was nominally degraded by these changes, with losses in the speed and climbing ability arenas. The A6M2 carried two 7.7 machine-guns firing synchronized through the propeller arc and a 20 mm cannon in each wing. Ammunition for the 20 mm was limited to about, without looking it up, 80 rounds per gun. The standard practice was for the A6M2 pilot to cut loose with his 7.7's for ranging (the 20 mm was somewhat short ranged) and then let go with the 20 mm's when on target. This pitter-patter of 7.7 could be another warning for an, up to that point, unwary F4F guy to get out of Dodge. The twin 7.7 was a typical 1930s, WWI rifle ammunition holdover. Against a plane armored such as the F4F they were relatively worthless.

So . . .

Speed - A6M2 is better, but it was not necessarily an advantage due to the maneuverability and engine cutoff problems. The F4F could out-dive an A6M2 any day and at top speed was more than more maneuverable. Offsetting advantages and disadvantages. 0 points.

Armament - F4F was better with the battery of six 50 cals outweighing the MG and cannon arrangement of the A6M2 in terms of range and impact. With only four 50 cals in the F4F-3 and the later FM series the weight was about equal, but "Ma-Deuce" was a much better gun. F4F, 1 point

Armor protection - F4F hands down … A6M2? What armor? F4F, 1 point.

Maneuverability – Goes to the A6M2, especially at low to mid speeds. Advantage goes away at top end speeds. The F4F was generally a better, more stable, firing platform as well; the A6M2, much more sensitive to control pressures, sometimes had a tendency to skid in firing situations (this tidbit from a USN F4F type ace who had the opportunity to fly B/N 4593, the famous Koga Zero, on several occasions in the fall of 1944). A6M2, 0.5 points

Climb - goes to the A6M2. F4F was not even in the park. A6M2, 1 point

Range – A6M2, but this led them into arrangements of long distance missions with minimal combat time and a long haul back, possibly with damage, such as in the Guadalcanal campaign, with little or no hope of air-sea rescue. The greater range was really only an advantage in terms ferrying from outpost to outpost or of loiter time in a CAP situation. Historically, the A6M2's range created more problems than it solved when it came to encounters with F4F's. 0 points.

Score (on my unofficial scale): F4F - 2; A6M2 - 1.5

My pick, in terms of survivability, which, of course is the bottom line, is the F4F. You can't fly combat if hits from a good solid burst tend to cause your plane to explode.

Regards,

 

[NTGray]

. . . truth be told, they were probably pretty close to equal with the positive qualities of one canceled out by the positive qualities of the other.

Exactly. One outstanding quality does not equal an overall superior airplane. (Two if you count range, but range has nothing to do with combat capability. As with the P-51 in the ETO, range only means that you can get the airplane to where you want it. After that it's all a matter of how good the plane itself is.)

Your "score sheet" was very thorough, and you covered in depth a part that many people probably don't know, which is that the huge maneuverability advantage only existed at lower speeds, was less at moderate speeds, and disappeared completely at high speed, where the Zero's ailerons were practically frozen.

Also (and this deals with the skill of the pilot rather than the virtues of the airplane), under the heading of "better tactics and training" I have found multiple mentions of the Wildcat pilots being better shots, with better training in deflection shots. The Zero pilots are said to be not equal to the Wildcat pilots in this area, even in the beginning when the Japanese pilots had a clear lead in flight hours and combat experience.

But what do you know about the radios? Since a radio is part of the airplane, a Zero not having one was a major disadvantage for the airplane itself. But was that lack corrected later on? I have not yet found a source that stated that radios were ever installed on Zeros, yet that seems hard to believe.