The Dornier Do 217 was a bomber used by the German Luftwaffe during World War II as a more powerful development of the Dornier Do 17, known as the Fliegender Bleistift. Designed in 1937 and 1938 as a heavy bomber but not meant to be capable of the longer-range missions envisioned for the larger Heinkel He 177, the Do 217's design was refined during 1939 and production began in late 1940. It entered service in early 1941 and by the beginning of 1942 was available in significant numbers.
The Dornier Do 17. The Do 217 was to be a larger, improved version in all areas.
Bf 110 using standard 900-litre drop tanks, tested for the Do 217
A power-egg is a complete "unitized" modular engine installation, consisting of engine and all ancillary equipment, which can be swapped between suitably designed equipment, with standardised quick-changing attachment points and connectors.
A BMW 801 Kraftei (power egg), being unloaded from a Gotha Go 242 transport glider. Russia, March 1943. Note the engine is already fitted with its cowling and cooling fan
A surviving Junkers Ju 88R-1 night fighter with Kraftei unitized-installation BMW 801 engines, RAF Museum London, 2007
The same aircraft with its engines removed, showing the bulkhead mounting points, 2016
A Merlin-powered, Beaufighter night fighter Mark II of No. 255 Squadron RAF at RAF Hibaldstow, September 1941, showing the Merlin Power Plants later used on the Lancaster.