Heavy bombers are bomber aircraft with the greatest bomb load carrying capacity and longest range of their era.
The B-17 had a Max takeoff weight of 65,500 lb (29,700 kg)
Short range missions (<400 mi): 8,000 lb (3,600 kg)
Long range missions (≈800 mi): 4,500 lb (2,000 kg)
Overload: 17,600 lb (7,800 kg)