Supermarine Spitfire. American Users, part five. The Spitfire in USAAF service. Part one, RAF Eagle squadrons.

 

The Supermarine Spitfire was employed by the United States Army Air Forces (USAAF) and, before that, three squadrons of the British Royal Air Force (RAF) manned by American volunteers, the so called 'Eagle Squadrons' employed the type. These three squadrons were Nos. 71, 121 and 133.

• No. 71 Squadron: This unit, probably the most famous of the Eagle squadrons, transitioned from the Hawker Hurricane to the Spitfire Mk.II in August 1941 and, shortly later, to the Spitfire Mk.Vb. The unit took part in the English Channel & Defence of Britain during 1941 and 1942 earning good reputation. When Japan attacked Pearl Harbor on 7th December 1941, many of it personnel volunteered to fight the Japanese in the Pacific, but their petition was refused, after which, they asked RAF Fighter command to move the squadron to Singapore to fight the Japanese, but this petition was also refused. 
  On 29th September 1942, this unit, together with the other two Eagle Squadrons was transferred to the USAAF, becoming the 334th Fighter Squadron of the 4th Fighter Group.
• No.121 Squadron: This formation, replaced the Hawker Hurricane with the Spitfire Mk.II in October 1941 and then with the Mk.Vb in November, which was when they claimed their first shot-down enemy aircraft. During the rest of 1941 and,  September 1942, they took part in the aerial defence of the English Channel, with some occasional bomber escort missions over mainland Europe. They were transferred to the USAAF on  29th September 1942 becoming the 335th Fighter Squadron of the 4th Fighter Group.
• No.133 Squadron: Just like the other two Eagle units, this squadron replaced the Hawker Hurricane with the Spitfire Mk.IIa in October 1941 and then, in early 1942, with the Mk.Vb. 
  When this unit was based in northern Ireland, transitioning from the Hurricane to the Spitfire, one pilot crash landed on the Republic of Ireland and he was interned. 
  The squadron took part in defensive operations over the English Channel and then, on 23rd September 1942 they were equipped with the much improved Spitfire Mk.IX and took part, on 26th September, in an escort mission over Morlaix, Brittany, western France. Due to confusion created by strong winds, the pilots mistook Brest (capital city of Brittany -under German occupation-) for England and force-landed there losing 11 out of 12 Spitfires, with four pilots being killed and six being taken prisoners (one of whom was later killed when taking part in escape from Stalag Luft III) and one evading capture. The remaining of the unit was transferred three days later to the USAAF, becoming 336th Squadron of the 4th Fighter Group. 
  The decision to transfer the squadron was, however, not influenced by the so-called 'Morlaix disaster', as it was part of a planned transfer of the three Eagle Squadrons to the USAAF.

To be continued...

Sources:

1st https://en.wikipedia.org/wiki/No._71_Squadron_RAF

2nd https://en.wikipedia.org/wiki/No._121_Squadron_RAF

3rd https://en.wikipedia.org/wiki/No._133_Squadron_RAF

4th https://www.memorialflightclub.com/blog/morlaix-disaster-26th-september-1942