In 1936 the company of Heinkel Flugzeugwerke received details of the new Bomber A specification from the RLM. This specification, first proposed by the RLM on June 3, 1936 - the same day that, ironically, General Walther Wever, the main proponent for the Luftwaffe to have a strategic bomber force in the first place, lost his life - called for an aircraft more advanced than the Dornier Do 19 or Junkers Ju 89 "Ural bomber" prototypes that General Wever had championed.

The Bomber A aircraft specification required the capability of carrying a bombload of at least 1,000 kg (2,200 lb) over a range of 5,000 km (3,100 mi), and possess a maximum speed of not less than 500 kph (311 mph) at altitude. This was a formidable specification, calling as it did for an aircraft able to outrun any modern fighter - as was expected with the top speeds of the main force Schnellbomber concept - and outperform, by a considerable margin, any bomber then in service. On June 2, 1937 Heinkel Flugzeugwerke received instructions to proceed with construction of a full scale mock-up of its Projekt 1041 Bomber A. The mock-up was completed in November 1937, and on November 5, 1937 allocated the official RLM type number "8-177", the same day that the Luftwaffe High Command (OKL) first stipulated the requirement for the new design to possess sufficient structural strength to enable it to undertake medium degree diving attacks. Heinkel Flugzeugwerke's estimated performance figures for Projekt 1041 included a top speed of 550 kph (342 mph) at 5,500 m (18,050 ft) and a loaded weight of 27,000 kg (59,500 lb). In order to achieve these estimates, Heinkel's chief designer, Siegfried Gunter, employed several revolutionary features.

• Powerplants
• Undercarraige
• Evaporative Cooling System
• Armament
• Wing Design
• Dive Bombing
• Prototypes

Sources:
Gunston, Bill - The Encyclodepia of the Worlds Combat aircraft, 1976, Chartwell Books, Inc., New York
Brown, Eric, Captain - Wings of the Luftwaffe, 1979, Airlife Publishing Ltd., Shrewsbury
Gunston, Bill & Wood, Tony - Hitler's Luftwaffe, 1977, Salamander Books Ltd., London
Donald, David - The Complete Encyclopedia Of World Aircraft, 1997, Brown Packaging Books Ltd., London
Wikipedia - Heinkel He 177