Piasecki H-21
Technical Specifications

First Flight: April 11, 1952
Number Built: 500+ for military and commercial service
Length: 86 feet  4 inches
Rotor Diameter: 2 @ 44 feet 6 inches each 
Height: 16 feet 
Max Take-Off Wt.: 13,300 lbs.
Empty Wt.: 8,000 lbs.
Max Cruising Speed: 135 mph  117 kts
Normal Cruising Speed:   98 mph    85 kts
Service Ceiling: 10,000 feet
Fuel Capacity: 300 US gallons
Range: 450 miles 
Fuel Type: 100/130 octane
Fuel Consumption: N/A
Engine: 1 Wright R-1820-103 rated @ 1425 HP 
Seating: 19 Passengers 
Crew: 2 Pilots 

Engine Specifications

 Wright R-1820-103

Type: 9 cylinder air cooled radial
Length: 48.35 inches
Diameter: 55.25 inches
Bore: 6.125 inches
Stroke: 6.875 inches
Displacement: 1820 cubic inches
Compression Ratio: 6.80 to 1
Dry Weight: 1362 lbs.
Ignition: Magnetos; Bosch S9LU-3
Fuel Grade: 100/130 octane
Carburation: Bendix PD-12K19
Performance: Take-Off: 1425 HP @ 2700 RPM
Normal: 1275 HP @ 2500 RPM