Douglas DC-7
Technical Specifications

First Flight: May 18, 1953
Number Built: 105 were built for commercial use
Length: 108 feet  11 inches
Wing Span: 117 feet  6 inches
Height: 28 feet  7 inches
Max Take-Off Wt.: 114,600 to 122,000 lbs.
Max Landing Wt.: 95,000 to 97,000 lbs.
Empty Wt.: 58,150 lbs.
Max Cruising Speed: 405 mph   352 kts
Normal Cruising Speed: 359 mph   312 kts
Approach Speed: 144 mph   125 kts
Landing Speed: 132 mph   115 kts
Stall Speed:   97 mph     84 kts
Service Ceiling: 28,400 feet
Fuel Capacity: 4512 US gallons 
Range: 5164 miles w/maximum fuel load
3565 miles w/maximum payload
Fuel Type: 115/145 octane
Fuel Consumption: 313 gph 4 engine flight plan burn w/max fuel
456 gph 4 engine flight plan burn w/max load
Engines: 4 Wright R-3350 turbo-compound rated at
3250 HP each 
Seating: 64 to 95 passengers
Crew: 3 Pilots 2 Flight attendents

Engine Specifications

 Wright R-3350-30W 

Type: 18 cylinder air cooled radial
Diameter: 61.2 inches
Length: 89.53 inches
Bore: 6.125 inches
Stroke: 6.312 inches
Displacement: 3350 cubic inches
Compression Ratio: 6.7 to 1
Dry Weight: 3514 lbs.
Ignition: Scintilla DLN-9
Fuel Grade: 115/145 octane
Carburation: Stromberg PR-58T1
Performance: Take-Off Power 3250 HP @ 2900 rpm
Normal Power 2600 HP @ 6500 ft
Remarks: The R-3350-30W is a compound version of the R-3350-26W using 3 small turbines driven by exhaust gas and connected by fluid couplings to the crankshaft. This increases the take-off power to 3250 HP.