Messerschmitt also tested its first Messerschmitt Bf 109 V1 prototype, bearing German civilian registration D-IABI, with a Kestrel engine in 1935 as the German-designed intended engines were not yet ready. Junkers also used a Kestrel for the first prototype of the Ju 87 "Stuka" dive bomber. The Reich Air Ministry (RLM) acquired four Kestrel VI engines by trading Rolls-Royce a Heinkel He 70 Blitz as an engine testbed.[6]