Only eight He 277B-5/R2 were completed before all bomber production was terminated in favor of the Emergency Fighter Program
Converted from an He 177A-3/R2 airframe with four DB 603A engines, the He 277 V1 flew at Vienna-Schwechat in the closing months of 1943. The second prototype, He 277 V2, was a conversion of a standard He 177A-5/R8 airframe and was flown on 28 February 1944. Minor directional instability displayed by the V1 and V2 resulted in the fitting of a twin fin and rudder tail unit to the He 277 V3, which had carried the earlier designation He 177B-5/V101. This aircraft's first flight, marked with the Stammkennzeichen (factory radio code) NN+QQ and which had serial number 535 550, was achieved on December 20, 1943. The main production version was to be the He 277B-5/R2 intended for heavy bomber operation over long ranges and powered by four DB 603A engines. Only eight He 277B-5/R2 were completed before all bomber production was terminated in favor of the Emergency Fighter Program.