Fort Worth, Texas, to Charleston, South Carolina or Savannah, Georgia
Chicago, Illinois, to Miami, Florida
"For the first time we had on the airline, an airplane that we didn't have to worry about fuel. We always had enough fuel on that DC-4 to go 2,000 miles, and somewhere in the United States, the weather was satisfactory for a let down within 2000 miles. So fuel was no problem…The DC-4 was very dependable airplane, had very dependable engines, had adequate anti-icing." Fritz Schwaemmle, hired as a Delta pilot in 1934.
The DC-4 had a simple autopilot system that provided altitude and directional hold.
Delta's first aircraft that was not a "tail-dragger." Because the cabin was level when the DC-4 was on the ground, it was easier to board and exit than earlier Delta aircraft.
Chief Engineer J. F. Nycum designed the galley for Delta's DC-4 aircraft, which were being converted from military C-54B Skymasters. Douglas Aircraft Company made Delta's galley the standard for all DC-4s coming off its modification line after World War II.
A Delta DC-4 flew the world's first nonstop scheduled flight between Chicago and Miami on November 1, 1946.
Eastern Airlines met Delta's challenge on the Chicago-Miami run with pressurized Lockheed Constellations, allowing smoother flights avoiding more bad weather, to counter Delta's unpressurized DC-4s. In 1948, Delta put the pressurized DC-6 into service.