The Heinkel He 277 was a four-engine, long-range heavy bomber design, originating as a derivative of the He 177, intended for production and use by the German Luftwaffe during World War II. The main difference was in its engines. Rather than using two fire-prone Daimler-Benz DB 606 "power system" engines, each of which consisted of side-by-side paired Daimler-Benz DB 601s and with each DB 606 "power system" weighing 1.5 tonnes apiece — or two of the similar DB 610, each of which used a pair of DB 605 engines in a similar "twinned" configuration on later He 177A airframes, the He 277 was intended to use four unitized BMW 801E 14-cylinder radial engines, each mounted in an individual nacelle and each turning a three-blade, four-meter diameter propeller.