Sorry I forgot to use that FLAPS

Wikipedia

The Douglas DC-4 is a four-engine (piston) propeller-driven airliner developed by the Douglas Aircraft Company. Military versions of the plane, the C-54 and R5D, served during World War II, in the Berlin Airlift and into the 1960s. From 1945, many civil airlines operated the DC-4 worldwide.
Role
Airliner/transport aircraft
National origin
United States
Manufacturer
Douglas Aircraft Company
First flight
14 February 1942 (production series)[1]
Introduction
1942 with United Airlines
Retired
1991
Status
In very limited use
Primary users
South African Airways Museum Society
United Airlines (historical)
American Airlines (Historical)
Trans World Airlines (Historical)
Buffalo Airways
Produced
1942 – August 1947
Number built
80[2] DC-4 and 1,163 C-54/R5D
Variants
C-54 Skymaster
Canadair North Star
Aviation Traders ATL-98 Carvair
Developed into
Douglas DC-6

Design and development

Following proving flights by United Airlines of the DC-4E it became obvious that the 52-seat airliner was too large to operate economically and the partner airlines[a] recommended a long list of changes required to the design. Douglas took the new requirement and produced a new design, the DC-4A, with a simpler unpressurised fuselage, R-2000 Twin Wasp engines and a single fin and rudder. Both designs included tricycle landing gear, unlike the predecessor 2-engine DC-3.

With the entry of the United States into World War II, in December 1941 the War Department took over the provision orders for the airlines and allocated them to the United States Army Air Forces with the designation C-54 Skymaster. The first C-54 flew from Clover Field in Santa Monica, California on 14 February 1942.

To meet military requirements the first production aircraft had four additional auxiliary fuel tanks in the main cabin which reduced the passenger seats to 26. The following batch of aircraft were designated C-54A and were built with a stronger floor, cargo door with a hoist and winch. The first C-54A was delivered in February 1943. With the introduction of the C-54B in March 1944, the outer wings were changed to hold integral fuel tanks allowing two of the cabin tanks to be removed; this allowed 49 seats (or 16 stretchers) to be fitted. The C-54C was a hybrid for Presidential use, it had a C-54A fuselage with four cabin fuel tanks and the C-54B wings with built-in tanks to achieve maximum range.

The most common variant was the C-54D, which entered service in August 1944, a C-54B with more powerful R-2000-11 engines. With the C-54E the last two cabin fuel tanks were moved to the wings which allowed more freight or 44 passenger seats.

A total of 1,163 C-54/R5Ds were built for the United States military between 1942 and January 1946; another 79 DC-4s were built postwar. A variant, equipped to fly over 40% faster, was built in Canada postwar as the Canadair North Star.

Enjoy:)