5: North American P-51A Mustang
Typically, tales of the P-51 Mustang focus on the B model and later, which were fitted with a Rolls-Royce Merlin engine with a two-speed supercharger. This enabled it to fight at the high altitudes typical of air warfare in the European theatre. This overlooks the low-level brilliance of the original P-51A.
Powered by an Allison V-1710 V-12 engine the P-51A had superlative performance up to 18,000 feet, above which its single-speed supercharger struggled to supply enough air. At ultra-low level, it was in many ways superior to the Merlin, able to run smoothly at slower speeds, giving lower fuel consumption while also being more reliable.
Following the RAF’s example, the USAAF would fit many of their P-51A with sideways facing K-24 cameras. This allowed them to excel in the Fighter-Reconnaissance role, operating in pairs one would fly a pre-planned route taking a series of overlapping photographs while the other provided cover. The Allison engine allowed them to outrun virtually every German fighter at low-level.
If necessary, the P-51A could also take on the best German fighters when intercepted allowing them to roam all over occupied Europe with relative impunity. Perhaps their most crucial role was helping map Normandy prior to the invasion of June 1944.
