Wolf in Sheep’s Clothing

Built from a Spitfire Mk. Vb airframe captured in November 1942, this curious aircraft was used by Daimler Benz for comparative trials between the DB 605 German engine and the Rolls-Royce Merlin.
Spitfire Mk. Vb serial no. EN 830 originally belonged to No. 131 “County of Kent” Squadron RAF and was marked NX – X. On 18 November 1942, being flown by P/O Bernard Scheidhauer of the Free French Air Force, this aircraft was hit by flak on a Rhubarb mission over the coast of Normandy. Scheidhauer made a forced landing in a turnip field at Dielament Manor, Trinity, Jersey and was taken prisoner. His aircraft, with only minor damage, was transported to Germany, eventually being sent to Echterdingen, where Daimler-Benz operated a flight testing division.
The Spitfire airframe no. EN 830 was converted by removing the entire engine section, and then adopting a DB 605 unit from a Bf 110G twin-engine fighter. Fortunately, the engine unit of the German twin was very similar in cross-section at the firewall to the Spitfire. A new engine support was designed, and a standard DB 605A-1 engine Werknummer 00701990 was mounted to the firewall. A standard 3.0 m diameter VDM propeller from the Bf 109G was added, together with the carburettor scoop from the same fighter.
The entire conversion including connecting the engine’s systems with the rest of the aircraft proved rather difficult. The work was completed at the Sindelfingen Daimler-Benz factory, near Echterdingen, which provided the necessary expertise and tooling.
The aircraft, marked with the Luftwaffe radio-call markings CJ+ZY and painted yellow underneath to facilitate recognition by the flak crews, underwent a series of flight tests in Echterdingen and Rechlin. It was reportedly very easy to fly, and one of the German pilots described it as “a dream of an aeroplane”, superior in handling to the Merlin-powered original. More importantly, the tests showed that the aircraft was markedly easier to handle on the ground and in the air than the Bf 109G.
Later, EN 830 was destroyed on 14 August 1944 in an American bombing raid.

source: Spitfiresite.com