WWII performance tests

[obvert]

Hi all. While looking at the FW-190 thread and links I came across this site. Some may know it, but it was the first I'd come across it. Lots of flight test data for WW2 planes, and many copies of original docs on these tests. Fun to dig through.

http://www.wwiiaircraftperformance.org

Reports like this are so telling:

[Buckrock]

Slight problem with that comparison report. The A6M2 in it was being performance tested at a maximum RPM of only 2050, which impacted heavily
on the stated rate of climb and speed and also explains why they thought even the P-36A was faster than the Zero.

The next listed comparison report "A6M2 (Navy Test)" at the website is the more representative one as they were able to use the Zero's engine
at its Japanese service maximum of around 2600rpm.

[obvert]

ORIGINAL: Buckrock

Slight problem with that comparison report. The A6M2 in it was being performance tested at a maximum RPM of only 2050, which impacted heavily
on the stated rate of climb and speed and also explains why they thought even the P-36A was faster than the Zero.

The next listed comparison report "A6M2 (Navy Test)" at the website is the more representative one as they were able to use the Zero's engine
at its Japanese service maximum of around 2600rpm.

Yes, and still the part that is most interesting is that the A6M was not constructed well enough to dive with US aircraft and had little ability to turn in a dive, thus setting up the basis for the boom and zoom tactics used so effectively throughout the war against this (and other) Japanese planes.

[PaxMondo]

ORIGINAL: obvert


...the A6M was not constructed well enough to dive with US aircraft ...

Not a construction flaw, but a design decision. The things (wing loading, surface area, etc) that made it turn so well limited the top speed. 350 max per the IJ. That's why bigger engine was NOT a solution for the A6M family, other than to allow armor and bomb loads. The aircraft design, which Horikoshi just nailed, was for a highly manouverable, long range fighter with max speed of 350. in 41/42 it could rule the skies. but once the allies had enough of a speed advantage ... well, history tells us that answer.

the next designs ALL needed bigger engines as they were designed to be 400 mph fighters, and to get to 400 mph they needed a LOT more HP.

BTW, the test you cited was a low altitude. At low altitude, the max speed of the A6M was lower ... it increased as altitude increased (air density here is the relevant variable). Again, all consistent with the design choices. So at 5000 ft the A6M would have fought at 250 - 300, at 20,000 +320. Dependent upon exact model and more specifically on the Ha-35 model in the plane.

[Yaab]

Dive-and-forget? Sounds like a kami weapon.

[Buckrock]

ORIGINAL: PaxMondo

BTW, the test you cited was a low altitude. At low altitude, the max speed of the A6M was lower ... it increased as altitude increased (air density here is the relevant variable). Again, all consistent with the design choices. So at 5000 ft the A6M would have fought at 250 - 300, at 20,000 +320. Dependent upon exact model and more specifically on the Ha-35 model in the plane.

Which shows the problems with their test Zero as the top speed was only 286mph at 10,000ft and 270mph at 20,000ft.

[PaxMondo]

ORIGINAL: Buckrock

ORIGINAL: PaxMondo

BTW, the test you cited was a low altitude. At low altitude, the max speed of the A6M was lower ... it increased as altitude increased (air density here is the relevant variable). Again, all consistent with the design choices. So at 5000 ft the A6M would have fought at 250 - 300, at 20,000 +320. Dependent upon exact model and more specifically on the Ha-35 model in the plane.

Which shows the problems with their test Zero as the top speed was only 286mph at 10,000ft and 270mph at 20,000ft.

And as you noted, engine speed. 500 rpm is a big deal on a radial engine prop ... and then boost ... emergency boost is also a big deal ...

[obvert]

ORIGINAL: PaxMondo

ORIGINAL: obvert


...the A6M was not constructed well enough to dive with US aircraft ...

Not a construction flaw, but a design decision. The things (wing loading, surface area, etc) that made it turn so well limited the top speed. 350 max per the IJ. That's why bigger engine was NOT a solution for the A6M family, other than to allow armor and bomb loads. The aircraft design, which Horikoshi just nailed, was for a highly manouverable, long range fighter with max speed of 350. in 41/42 it could rule the skies. but once the allies had enough of a speed advantage ... well, history tells us that answer.

the next designs ALL needed bigger engines as they were designed to be 400 mph fighters, and to get to 400 mph they needed a LOT more HP.

BTW, the test you cited was a low altitude. At low altitude, the max speed of the A6M was lower ... it increased as altitude increased (air density here is the relevant variable). Again, all consistent with the design choices. So at 5000 ft the A6M would have fought at 250 - 300, at 20,000 +320. Dependent upon exact model and more specifically on the Ha-35 model in the plane.

Just reading the report where it says construction was mediocre. [:)]


I'm sure all of the rest that you mention is true. I didn't post to argue a point on A6M construction, but I did find the dive test originally posted interesting because it explained something I didn't know, which was that in a high speed dive the A6M lost the ability to turn away from a pursuing plane.

I just think it's cool seeing the reports that originally confirmed some of what successful Allied pilots had been doing in the early war.

[PaxMondo]

ORIGINAL: obvert



Just reading the report where it says construction was mediocre. [:)]

Ahh, now i see where you were going. Yes, IJ factories weren't up to US standards at that time. Tolerance were wider than would have been acceptable then.

The lack of sectionalization again is a design decision. Sectioning adds weight. It does greatly improve repair capability, assuming the aircraft arrives home.

Given the overall design theme, I would tend to agree with Horikoshi's decision against sectionalizing. The plane is so light and has no armor, the probability that an aircraft would survive to make it home with damage to be repaired is going to be low, so reducing performance to account for it would be counter-productive.

I don't know, but I suspect that if any actual damage/repair data was available on the A6M, the design decision was proven to be correct here.

[crsutton]

ORIGINAL: obvert

ORIGINAL: PaxMondo

ORIGINAL: obvert


...the A6M was not constructed well enough to dive with US aircraft ...

Not a construction flaw, but a design decision. The things (wing loading, surface area, etc) that made it turn so well limited the top speed. 350 max per the IJ. That's why bigger engine was NOT a solution for the A6M family, other than to allow armor and bomb loads. The aircraft design, which Horikoshi just nailed, was for a highly manouverable, long range fighter with max speed of 350. in 41/42 it could rule the skies. but once the allies had enough of a speed advantage ... well, history tells us that answer.

the next designs ALL needed bigger engines as they were designed to be 400 mph fighters, and to get to 400 mph they needed a LOT more HP.

BTW, the test you cited was a low altitude. At low altitude, the max speed of the A6M was lower ... it increased as altitude increased (air density here is the relevant variable). Again, all consistent with the design choices. So at 5000 ft the A6M would have fought at 250 - 300, at 20,000 +320. Dependent upon exact model and more specifically on the Ha-35 model in the plane.

Just reading the report where it says construction was mediocre. [:)]


I'm sure all of the rest that you mention is true. I didn't post to argue a point on A6M construction, but I did find the dive test originally posted interesting because it explained something I didn't know, which was that in a high speed dive the A6M lost the ability to turn away from a pursuing plane.

I just think it's cool seeing the reports that originally confirmed some of what successful Allied pilots had been doing in the early war.

Yes, this was an accepted escape maneuver for Allied fighters of the same generation. A high speed dive with a turn away once the zero followed as the zero, once dive speed was attained, just could not follow the turn. Well, that is if the zero did not shed it wings. Although it could not ultimately turn with a zero, the P40 had a much faster roll rate at speed. So in many combat situations this gave the P40 an edge simply because it could begin to turn faster. It just could not sustain the advantage so a skilled pilot would not try to hold a turn with a zero but for a second or two, could have an edge.

[Alpha77]

Just as a counter point to above "mediocre", I had read in a longer thread at a plane forum from some guy who preserves planes, and he stated the the quality of build was as good as any other plane (he mentioned the engine mainly, which he said had as good parts and still worked like US,German or Brits ones). I beleive he was from a quite known plane collecter, preserver... or whatever you call the guys. Maybe from this "Planes of Fame Museum located in Chino, California."

And perhaps this the plane then he examined and/or worked on:

https://www.youtube.com/watch?v=ZuoVlQOO4xc

[m10bob]

The paper on the OP's post must be early observations. The info contains flawed information, likely meant to encourage American pilots.

It is true NOTHING could out-roll a Curtiss P 40, but in a sustained turn, the Zeke was by far the better plane, and the P 36 could certainly not out-climb a Mitsubishi.

When a plane turns, it loses both speed and altitude, and is determined by the weight to power ratio.
The Zeke was very light in its' earlier versions, with no armor and was designed to be maneuverable as a means to defeat what the Japanese knew were the opponents heavier ARMORED planes.
They were counting on the enemy having planes with less turning capabilities.
As the saying went in 1942...NEVER turn with a Zero.

I offer this comment from the standpoint of a former pilot.
As noted above...in time the Allies defeated the strengths of the Zero with "boom and zoom" tactics.

[Big B]

I think sustained turn is the key phrase here.
I believe roll rate, aileron & rudder authority, and initial speed pretty well determine the first 180 degrees of a turn...all of which diminish in importance as speed drops if turning/circling is sustained.
After that it's physics and as Chuck Yeager said - pilot skill.

ORIGINAL: m10bob

The paper on the OP's post must be early observations. The info contains flawed information, likely meant to encourage American pilots.

It is true NOTHING could out-roll a Curtiss P 40, but in a sustained turn, the Zeke was by far the better plane, and the P 36 could certainly not out-climb a Mitsubishi.

When a plane turns, it loses both speed and altitude, and is determined by the weight to power ratio.
The Zeke was very light in its' earlier versions, with no armor and was designed to be maneuverable as a means to defeat what the Japanese knew were the opponents heavier ARMORED planes.
They were counting on the enemy having planes with less turning capabilities.
As the saying went in 1942...NEVER turn with a Zero.

I offer this comment from the standpoint of a former pilot.
As noted above...in time the Allies defeated the strengths of the Zero with "boom and zoom" tactics.

[Macclan5]

Tactics including: boom and zoom, the thatch weave, TRACOM training, etc, did indeed make the difference.

The Americans - perhaps best of all the Nations involved in the war (it can be argued) - learned to adapt plane tactics specific to the plane against their opponent(s).

The notable exception to this rule is likely the P38 Lightning which alone of American air frames suffered from a "well defined role and tactics" especially in the early war.

This is not to downplay all other Nations accomplishments on a limited basis be it in airframes or pilot tactics; merely to state the Americans were the best also includes the factors that their pilot pools were much more robust and of course they had a vast peaceful home front with fantastic diversity of terrain to accomplish this training.

Either way it is an asset in their air war ledger.

-- Side note on the much maligned P40 Curtis (various iterations).

I read in a book (another obscure reference - sorry) where post war analysis of the P40 record as an Air Superiority Fighter was actually much better than is generally supposed.

I think perhaps one of those "Encyclopedia of WW2 facts' type book.

Wikipedia says a similar thing.

The losses per sortie ratio (one measure - but an important one) was at least comparable to many of the "better aircraft" that historians consider to be "best American Technology" i.e. the Corsair, the Jug, the Mustang.

Losses include operational, air to air, accident, etc.

But you have to be able to fly the plane to kill an enemy or provide combined tactical support.

This of course includes the fact that the P40 saw action in places like North Africa (against inferior Italian Airframes) and Burma (against inferior Japanese Airframes).

But the note in particular mentions this in the sense that the P40 flew practically everywhere! In extreme conditions.

It was dependable and rugged, it flew thousands upon thousands of sorties, and with the correct tactics competed or bettered the Axis opponent in many instances.

[Big B]

Specificly regarding P-40 vs Zero, wiki

From Robert DeHaven who flew with the 49th FG;

The 49th Fighter Group was in action in the Pacific from the beginning of the war. Robert DeHaven scored 10 kills (of 14 overall) in the P-40 with the 49th FG. He compared the P-40 favorably with the P-38:

"If you flew wisely, the P-40 was a very capable aircraft. [It] could outturn a P-38, a fact that some pilots didn't realize when they made the transition between the two aircraft. [...] The real problem with it was lack of range. As we pushed the Japanese back, P-40 pilots were slowly left out of the war. So when I moved to P-38s, an excellent aircraft, I did not [believe] that the P-40 was an inferior fighter, but because I knew the P-38 would allow us to reach the enemy. I was a fighter pilot and that was what I was supposed to do."[63]
The 8th, 15th, 18th, 24th, 49th, 343rd and 347th PGs/FGs, flew P-40s in the Pacific theaters between 1941 and 1945, with most units converting to P-38s during 1943-44. In 1945, the 71st Reconnaissance Group employed them as armed forward air controllers during ground operations in the Philippines until it received delivery of P-51s.[58] They claimed 655 aerial victories.

Contrary to conventional wisdom, with sufficient altitude the P-40 could actually turn with the A6M and other Japanese fighters, using a combination of a nose-down vertical turn with a bank turn, a technique known as a low yo-yo. Robert DeHaven describes how this tactic was used in the 49th Fighter group:

[Y]ou could fight a Jap on even terms, but you had to make him fight your way. He could outturn you at slow speed. You could outturn him at high speed. When you got into a turning fight with him, you dropped your nose down so you kept your airspeed up, you could outturn him. At low speed he could outroll you because of those big ailerons ... on the Zero. If your speed was up over 275, you could outroll [a Zero]. His big ailerons didn't have the strength to make high speed rolls... You could push things, too. Because ... f you decided to go home, you could go home. He couldn't because you could outrun him. [...] That left you in control of the fight.

[BBfanboy]

The US did have the benefit of analyzing the battle experience of the AVG fighters in China before the USAAF got into the war.
But they also benefitted a good deal from British training and advice on air combat. The British were well acquainted with matching tactics to the type of enemy aircraft they were fighting.

That said, the US was the only country (AFAIK) that had the resources to dedicate a unit to retrieving, repairing and test-flying enemy aircraft to get the kind of intel seen in the reports on the Zero in this thread. The British did a bit of that with aircraft that landed on their soil, but AFAIK not with a dedicated intel unit.

[Buckrock]

The RAF had the Air Fighting Development Unit, formed in 1940 which amongst its roles flight evaluated captured enemy aircraft and developed tactics for use against them.

[BBfanboy]

ORIGINAL: Buckrock

The RAF had the Air Fighting Development Unit, formed in 1940 which amongst its roles flight evaluated captured enemy aircraft and developed tactics for use against them.

Didn't know that - thanks for pointing it out. [:)]

[m10bob]

ORIGINAL: BBfanboy

"The US did have the benefit of analyzing the battle experience of the AVG fighters in China before the USAAF got into the war."

My old friend...this one statement is based on a deep-rooted myth.
The AVG never conducted a single combat mission prior to Pearl Harbor.
Chennault himself was the only "member" to have served in China prior to that as he was re-organizing the CAF.
Of course, the USAAF had not been "named as such, yet...My dad washed out of the old USAAC due to requirements which were later dropped (as described in Eric Bergeruds' great book, FIRE IN THE SKY.....)

Trivia...Greg Boyington was not well liked in the AVG as he was considered a "showboat" and was seen to take too many risks, but as Boyington pointed out...the AVG WAS a mercenary business and they only got paid for performancs.

[Buckrock]

The US at least did get regular warnings pre-war from Chennault in China about the existence of a Japanese "super-fighter".
The US also received fairly accurate Chinese intelligence assessments in mid '41 on the Zero and its performance. Even photos.