Helicopter HP/kg

• 10 lb per hp - this specifies 130 HP for 1300 lb weight [1]. 260 lb engine [2] 1300 lb total weight.
• 7 lb/HP - [3]
• 5 lb/HP for heavy cargo of 10 tons [4]. 2000 lb engine weight to 50000 lb gross [5] - engine weight to lift power is more favorable
  • Hp is astronomical (10000 HP) but weight is tiny (2000 lb)
• Motor weight to lift is 1:5 for light copter, and 1:25 for heavy cargo copters.