I interviewed a number of 5th AF fighter pilots before writing Fire in the Sky. Robert DeHaven (14 kills, 10 in a P40) was one of the most interesting. Talking to a pilot doesn't necessarily tell you much about the technical - some were interested in the fine points of their planes, others weren't. (Edwards Park who wrote for the Smithsonian and was a P39 jockey made that point in his memoirs.) DeHaven once said that he thought he flew a bumblebee - big heavy metal things shouldn't fly: but his plane was too stupid to know it, so it flew. To put it mildly the Oscar certainly made an impression. Anyone who saw them in action during 1943 when they flew in numbers at places like Wewak was startled by the maneuverability of the plane. DeHaven claimed he saw one perform a "double Immelmann" - a maneuver you'd expect to see at an airshow. For reasons Americans never really understood, when present in large units, Japanese aircraft would often do complex maneuvers while in sight but not range of US planes: build morale? entice someone into a dogfight? Anyway, the Oscar was probably the only operational monoplane fighter in WWII that was more nimble than the Zero. But at a very serious cost. To get speed over 300 mph and retain the kind of maneuverability wanted by Japanese pilots (who had an unusual influence in aircraft design) the Ki-43 was put on a serious weight reduction plan. Like the Zero it had many innovative features. However, it shared every disadvantage of the Zero vs US fighters except more so. The Ki-43II on paper could make 330mph at 12,000 feet. The A6M2 put out 345 at 15,000 ft, the A6M5 350mph at 20,000. (In the front lines, fighters almost never performed up to specs. Indeed with the technology available in the early 40s it was not possible to measure performance with the precision found in later decades. That's one reason why it's hard to find two sets of performance figures that agree with each other. For US WWII fighters the "go-to" source has to be "America's 100,000" by Francis Dean. It's a large format Schiffer book and will delight anyone who likes graphs. Dean was an aviation engineer and knew the topic.) Figure about 350 at 16,000 feet for a P-40E. The speed and critical altitude for the second generation US fighters left both the Oscar and Zero in the dust. The P38G did 400mph at 26,000, the Corsair 390 mph at 24,000 etc. As far as the Oscar goes, it would have fought 5th AF P-40s and P-38s in the Pacific. Pay attention to critical altitude - if a plane performs well up high, you can expect to see it up there. What that meant in the Pacific is that the Oscars spent a lot of time looking up at an enemy - never good. P40s were happier at mid-alt but it was more nimble than the P-38 and could out-roll an Oscar at high speed. US planes got into trouble if they lost too much energy - at anything under 250 and Oscar would gain six in seconds. Of course US airplanes could get into trouble not seeing the enemy - that was true anywhere, and explained why any well flown fighter was dangerous. But US pilots favored disciplined group tactics - if a flight of P38s kept up their speed they could pass through a Japanese formation (perfectly willing to trade "headers") - the Japanese would scatter or an inexperienced pilot would react too slowly. No matter what if the US planes kept up their speed they would find victims and they would be beastly hard to shoot down. And if the first pass failed, they'd gain altitude, turn and make another pass: and another. The Japanese learned to hate the P-38.
The Ki-43 did fine work in China, yet even the mediocre Tojo was preferred there. The reason that 5,000 Oscars were built was because it was a plane that worked and Japanese industry was able to make and keep flying. (10,000 Zeros were produced for the same reason - both marks until VJ day). Japanese pilots were most eager to get better planes and Japanese industry tried very hard to produce them. The Ki-61 was certainly an improvement, but even this well tried design spent a lot of time on the ground because engines were poorly constructed. By 1944 the Ki-84 was showing up and was a fine plane - when it was off the ground. (The same could be said about any second generation Japanese fighter. Arguably the best of the lot was the Ki-100 because it's radial gave it good performance and was pretty robust.)
So admire the Oscar if you like. It has lovely lines, although I prefer the Zero's. (To my eye the enemy made lovely planes - the Zero, FW-190 and BF-109 were all very handsome. Ours were business-like but lacked crisp lines. Even the Spit, to my eye, has an odd wing. Others may have different views.) But it's wrong to call the Oscar an underrated fighter. It was a modern fighter. It could shoot down planes if the situation was right. But it had only the lightest of armor, it's "self sealing" tanks didn't work against .50 caliber guns, and it didn't stand a chance in a dive against any opponent. It was seriously inferior to its American opponents - you didn't send a fragile plane with two mgs into a war of attrition against tough and well armed planes like those flown by 5th AF. Again, the Japanese were the best judge of things. Their finest engineers spent the war years trying to produce planes better than the Oscar and Zero.
The Ki-43 did fine work in China, yet even the mediocre Tojo was preferred there. The reason that 5,000 Oscars were built was because it was a plane that worked and Japanese industry was able to make and keep flying. (10,000 Zeros were produced for the same reason - both marks until VJ day). Japanese pilots were most eager to get better planes and Japanese industry tried very hard to produce them. The Ki-61 was certainly an improvement, but even this well tried design spent a lot of time on the ground because engines were poorly constructed. By 1944 the Ki-84 was showing up and was a fine plane - when it was off the ground. (The same could be said about any second generation Japanese fighter. Arguably the best of the lot was the Ki-100 because it's radial gave it good performance and was pretty robust.)
So admire the Oscar if you like. It has lovely lines, although I prefer the Zero's. (To my eye the enemy made lovely planes - the Zero, FW-190 and BF-109 were all very handsome. Ours were business-like but lacked crisp lines. Even the Spit, to my eye, has an odd wing. Others may have different views.) But it's wrong to call the Oscar an underrated fighter. It was a modern fighter. It could shoot down planes if the situation was right. But it had only the lightest of armor, it's "self sealing" tanks didn't work against .50 caliber guns, and it didn't stand a chance in a dive against any opponent. It was seriously inferior to its American opponents - you didn't send a fragile plane with two mgs into a war of attrition against tough and well armed planes like those flown by 5th AF. Again, the Japanese were the best judge of things. Their finest engineers spent the war years trying to produce planes better than the Oscar and Zero.
