Hi Tony,
>Well OK, having done some digging

However, the P-47D started with 2,300 hp and went on to 2,500+hp, and when it came out in 1943 the most common German fighter was the Bf 109G series with a basic 1,475 hp ...
A P-47D-25RE had 2535 HP for about 6600 kg take-off weight. That gave a power-to-mass ratio of 0.38 HP/kg. A Me 109G-6/R6 with underwing gondolae had 1475 HP for 3350 kg, or a power-to-mass ratio of 0.44 HP/kg.
And that's just the rated power at sea level - the DB605A additionally yielded exhaust thrust worth two or three hundred extra horse power at top speed.
>some models had a short-term MW boost of up to 1,800 hp, although I gather this became less common from 1944
Quite the opposite - higher outputs became more common as the war progressed. The second single-engine fighter of the Luftwaffe, the Fw 190A, had about 1800 HP in 1943 and increased that power, too. The Fw 190D actually exceeded the 2000 HP mark and (just as any non-turbocharged fighter) added considerable extra thrust to that.
>So with such divided attention, I can't see wingmen contributing anything to the attack in aerial combat, unless their leaders became detached or were shot down.
Hm, I suggest lecture of Shaw's "Fighter Combat", especially on "loose deuce" and "double attack" tactics :-)
>I agree that the percentage of fighter pilots who were taken by surprise is the key issue, but how do you know that the common statement (that most of them were) is misleading? Do you have any data on this?
As far as I know there is no data on this, and this is the reason I consider our statement that usually comes with a 80% to 90% percentage claim nonsensical. Even a brief look at the available combat reports should be enough to convince anyone that in a full-scale war, the lion's share of the fighting occurred between formations of fighters that were well aware of each other. In the few instances when a formation was taken by suprise by an enemy formation, that's usually noted in the squadron's annals as "black day", with losses exceeding the average percentage by far. However, these black days were few and far between.
>I recall that some Bf 110 units got so discouraged that when faced with RAF fighter attacks they formed defensive circles and relied on their rear gunners - not a good idea, since the attacking fighters had far more firepower and accuracy.
Actually, the key in a defensive circle is that you use your forward firing guns to protect the guy in front of you. Defensive circles were also used by Allied fighter bombers in North Africe though they didn't have any rear firing guns at all.
>IIRC the early users of the Bristol Fighter in WW1 made the same mistake of relying on their rear gunners and suffered badly, until they realised that they needed to fly and fight the plane exactly as if it were a single-seater, with rear gunner being a useful pair of eyes and 'sting in the tail'. After that, it became very successful.
Well, it might well have been even more successful had it been designed as a single-seater from the outset. For a 1200 kg fighter, the elimination of 150 kg of rear gunner and equipment makes a huge difference. Maybe we have just found the most overlooked missed opportunity in WW1 aviation ;-)
Regards,
Henning (HoHun)