Mil Mi-10 Mystery Cache

The Mil Mi-10 (NATO reporting name Harke), given the product number izdeliye 60, was a Soviet military transport helicopter of flying crane configuration, developed from the Mi-6, entering service in 1963.

The advent of the Mi-6 gave the Soviet Union the very useful ability to move and place large, bulky or heavy loads with precision. Limitations of the Mi-6 in the flying crane role included a weight to payload ratio and the inability of the crew to easily see the load and its intended final position. A Council of Ministers directive of 20 February 1958 tasked OKB-329 (OKB Mil) with the development of a dedicated flying crane helicopter for carrying bulky loads unable to be carried in the hold of a Mi-6.

General characteristics:

• Crew: 4 or 5 (pilot, copilot, flight engineer, navigator/radio operator and optional technician)
• Capacity: 28 passengers or 3 t (3,000 kg; 6,600 lb) internally up to 15 t (15,000 kg; 33,000 lb) payload on platform or 8 t (8,000 kg; 18,000 lb) max slung payload
• Length: 32.86 m (107 ft 10 in) , Mi-10K 32.4 m (106 ft) ignoring rotors
• Empty weight: 27,100 kg (59,745 lb) , Mi-10K 25,450 kg (56,110 lb)
• Gross weight: 43,550 kg (96,011 lb) , Mi-10K 37,000 kg (82,000 lb)
• Max takeoff weight: 43,700 kg (96,342 lb) , Mi-10K 38,000 kg (84,000 lb)Ground clearance under fuselage: 3.75 m (12.3 ft)
• Powerplant: 2 × Soloviev D-25V turboshaft, 4,100 kW (5,500 hp) each
• Main rotor diameter: 35 m (114 ft 10 in)
• Main rotor area: 962 m2 (10,350 sq ft)

Performance:

• Maximum speed: 335 km/h (208 mph; 181 kn) , Mi-10K 350 km/h
• Cruising speed: 180 km/h (112 mph; 97 kn) , Mi-10K 228 km/h
• Range: 430 km (267 mi; 232 nmi) , Mi-10K 500 km
• Disk loading: 45.27 kg/m2 (9.27 lb/sq ft) , Mi-10K - 38.46 kg/m² (7.87 lb/sqft) at normal AUW
• Hovering ceiling out of ground effect: Mi-10 3,000 m (9,800 ft), Mi-10K 1,000 m (3,300 ft)
• Hovering ceiling in ground effect: Mi-10K 3,000 m (9,800 ft)
• Dynamic ceiling: Mi-10K 4,750 m (15,580 ft)