Hi Oldman,
>I'll bet we can all agree that, notwithstandin their success in other theaters, the P-38 groups in the 8th AF did not do well, compared to their P-47 brethren or the early 51 groups. Regardless of paper performance, why do you think this was so?
In my opinion, the main reason was the thick wing root and the resulting Mach-induced problems. Before the advent of the compressiblity flaps (which were no dive brakes), the P-38 not only had the lowest tactically useful Mach number of all the fighters in the ETO, but it was also severely limited when it came to high-speed turns and at high-altitude actually lost turning performance at any speed, compared to fighters with the then-standard NACA 5-digit profiles. As high operating altitudes were the order of the day in the ETO, these effects combined to make the P-38 a rather unmanoeuvrable ship.
Contrary to what has been claimed here, the P-38 was not very manoeuvrable in the rolling plane either. Fully established roll rate might have been good (with hydraulically powered ailerons at least, which weren't initially available in the ETO), but the P-38 had a lot of mass out of the centreline - engines and turbosuperchargers -, so roll acceleration suffered terribly compared to a single-engined fighter. I'm sure you're aware that Shaw's "Fighter Combat" rates roll accelleration as more important than roll rate - rolls have to be quick to change the plane of the maneouvre, and you hardly ever roll more than 180° anyway.
In my opinion, these were the two main factors that made the P-38 a failure in the ETO (with Mach effects clearly ranking number one). General Doolittle called the P-38 "a second-rate fighter", and if you only look at its high-altitude capabilities, this verdict seems fully justified.
Regards,
Henning (HoHun)