Hello jmcalli2,
I was a bit busy earlier today when I was responding to your post, so I figured I go into a bit more detail now that I have a bit more time.
The problem the P-39 had in the PTO was in large part due to the USAAC being at the bottom of the learning curve in tactics and maintenance while the Japanese were experienced in both.
The Japanese had their logistics worked out, the USAAC did not.
The Japanese really didn't have any particular advantage in experience in terms of maintenance. Their types were just as new.
As for Japanese logistics, in some places it was pretty good. In places such as New Guinea, it was much worse than what the Allies were experiencing. The Japanese Army had it particularly bad. Anything past basic repairs needed to be shipped out because facilities did not exist in theater.
The P-39s were often sent up to intercept Japanese bombers flying at 20,000 ft. It would take 6-8 minutes for a P-39 to reach them, by which time the bombers would be gone. Meanwhile, the climbing P-39s would be bounced by A6Ms.
The biggest problem which P-39 Expert pointed out was that the early P-39 with a drop tank could not really get up past 17-18,000 feet. It also had very reduced performance past 20,000 feet even without a drop tank as noted from the IIS 85 Report you mentioned and I have quoted the section in a prior post.
Try reading P-39/P-400 vs A6M3 Zero New Guinea 1942 by Michael John Claringbould. It has some good combat accounts, some of which will say the P-39 and A6M were close in speed, some were the P-39 was faster, likely due to acceleration being close for the two aircraft. But the main reason to read the book is the in-depth look at combat records; the P-39 and A6M were even in the win-loss stats. That surprised me.
The P-39 had a speed advantage at just about every altitude. Sometimes it wasn't very large but speed isn't the only thing.
At low to medium speeds, the A6M in most models had a very significant Acceleration advantage. That is why the acceleration tests in IIS 85 were started at such odd speeds (generally only about 30-40 MPH below the maximum level speed of the A6M2).
When an aircraft is near its maximum speed, acceleration isn't going to be good.
As I see it, there are quite a few reasons why the Japanese pilots may not have done so well. Lack of communications and coordination is a major factor.
As for the A6M having a service ceiling of 35-38,000 ft, that didn't mean that it fought at that height.
Service ceiling means the rate of climb is 100 feet/minute.
I actually pointed out the same thing in a prior post when I commented that although the A6M2 had a service ceiling of 35,000 to 38,000 feet depending on the data source, that doesn't mean it was a high altitude fighter.
A6M performance fell off at 20-22,000 ft, like the P-39's did at 18,000 ft. That 2-4,000 ft made a difference.
This depends on which version of the A6M you are comparing. The A6M2 had a critical altitude of 4200 Meters which is not substantially higher than the early P-39 and performance past 20,000 feet was not so good. The A6M3 had a critical altitude in high blower of 6000 Meters (19,685 feet), so 20-22,000 feet was where it should have been performing best. Below that altitude, it was not as effective as the A6M2.
- Ivan.