Douglas introduces the self-contained freight lift | Aviation Week, December 12, 1949

 

Douglas Aircraft Co. Inc.'s new DC-6A Liftmaster, freighter version of the DC-6 passenger plane, carries along its own powered, loading elevator capable of hoisting 4000 lb. from approximately truckbed height to cabin floor level.

The elevator may be attached to either front or rear cargo door and can be folded and stowed within the fuselage, behind the rear door. The installation should offer distinct advantage for military and commercial operations at airports where ground freight-handling equipment is not available.

►Elevator Operation-Vertical component carrying the guide rails for the lifting platform is fastened to the bot- tom sill of the cargo door opening. Electric power for the motor operating the lift is supplied by an auxiliary gas engine coupled to a generator.

To handle small vehicles, the plat- form can be fitted with turntable track- age. A ramp-type adapter allows the vehicle to be driven up on the platform. When the platform is raised to fuselage floor level, the trackage can be rotated to permit the vehicle to enter the plane.

For stowage, the platform is lowered to the bottom of the guide rails and folded against the vertical component, whose fasteners are then released. Both are then pulled into the plane by electric power through a cable and pulley arrangement, and held behind the large aft section of the double rear door.

► Production Model - Automatically controlled cabin pressurization and air conditioning systems will permit high altitude transportation of perishable cargo. And leading edges of wing and tail have thermal anticing provisions incorporated.

Latest plans are to fit the production model with Pratt & Whitney R-2800- CB-17 engines rated at 2500 takeoff hp. with water-alcohol injection, and 1900 hp. maximum continuous cruise. Props will be Hamilton Standard or Curtiss high-activity units.

Takeoff at full gross weight of 100,000 lb. will be within 5050 ft. at sea level. Landing field length at 85,000 lb. is 5020 ft. Absolute range with 4700 gal. of fuel is 4475 mi.

Cargo volume is 5000 cu. ft. and the craft will carry 28,800 lb. payload over long distances at better than 315 mph.