Key to more Mustangs is USAAC ordering hundreds more A-36 Apaches. Once they recognize how much faster the A-36 airframe is, USAAF orders thousands of P-51B, etc.
Yes, P-51Ds had a large, L-shaped fuel tank behind and below the cockpit. Yes, that fuel tank pushed the centre-of-gravity too far aft, reducing stability and reducing maneuverability. But, on long-range escort missions, most of that (un-balancing) fuel had been burned off before they encountered significant numbers of German interceptors.
Trivia, most the surviving P-51s that are still flying (in 2016) have lost their long-range fuel-tanks and have a second seat installed in its place.
Speaking of German interceptors ...... Yes, Messerschmitt 109s were "twitchy" during landings and take-offs, but I suspect that many were damaged during landing after being shoot-to-pieces in battle and collapsed on landing.
Given the Me-109's modular construction, mechanics could (comparatively) easily canabilize 3 damaged 109s to re-assemble one airworthy airframe.
Early in the war, it was not obvious that Merlins were significantly better than Allisons, ergo little incentive to shut-down Allison production lines to re-tool them for Merlins. Alison's were still competitive at lower altitudes.
At a minimum, all Allison needed was an engineer as bright as Ricardo or Hooker to refine their super-chargers so that they competed directly with Merlins at higher altitudes.
Yes, P-51Ds had a large, L-shaped fuel tank behind and below the cockpit. Yes, that fuel tank pushed the centre-of-gravity too far aft, reducing stability and reducing maneuverability. But, on long-range escort missions, most of that (un-balancing) fuel had been burned off before they encountered significant numbers of German interceptors.
Trivia, most the surviving P-51s that are still flying (in 2016) have lost their long-range fuel-tanks and have a second seat installed in its place.
Speaking of German interceptors ...... Yes, Messerschmitt 109s were "twitchy" during landings and take-offs, but I suspect that many were damaged during landing after being shoot-to-pieces in battle and collapsed on landing.
Given the Me-109's modular construction, mechanics could (comparatively) easily canabilize 3 damaged 109s to re-assemble one airworthy airframe.
Early in the war, it was not obvious that Merlins were significantly better than Allisons, ergo little incentive to shut-down Allison production lines to re-tool them for Merlins. Alison's were still competitive at lower altitudes.
At a minimum, all Allison needed was an engineer as bright as Ricardo or Hooker to refine their super-chargers so that they competed directly with Merlins at higher altitudes.