PCAs main route was between Washington and Buffalo with three stops in between. 1939 saw the airline making extensions to this basic route, going southwards toward Knoxville using the Boeing 247D twins.

By 1942 PCA was flying two Boeing 247D twins and sixteen Douglas DC-3s, the latter to compete with the larger airlines flying against it. United began a route with DC-3s on the Chicago to Washington in 1943 and the airline needed some way of competing against the giants of US aviation.

In 1944 the US C.A.B. allowed PCA to compete on the New York - Chicago (via Pittsburgh and Detroit) route in competition with United Airlines (DC-3s), TWA (Stratoliners and Constellations) and American Airlines (DC-3s).

The direct route between Washington and Chicago was finally awarded to PCA in 1945 and PCA flew DC-3s against the United Air Lines service that had been established two years earlier.

In 1946 PCA introduced Douglas DC-4s in an attempt to gain ground on its competitors.

On April 21 1948 PCA changed its name to Capital Airlines. On November 4 1948 Capital Airlines made a 'first' in American airline history when it introduced a new low-fare 'coach' service - called the 'Nighthawk' service.

By the 1950s Capital Airlines was flying Douglas DC-4s and Lockheed L-049 Constellations.

Capital Airlines was looking forward again in the early 1950s when it ordered sixty Vickers Viscount 700 turboprops in 1954 and 1955 after consulting with the aircraft's launch customer, British European Airways , which had ordered a large fleet and were flight testing them on the London - Paris route with great success.

The first Viscount saw Capital service on 26 of July 1955 on the prestigious Washington to Chicago route with flights initially three a day. This new aircraft gave Capital a real gain over its competitors.

Vickers Viscount 800 N7450 of Capital Airlines in 1959 - Bill Armstrong

Capital Airlines ordered another 15 Viscounts to its great success, along with orders for another British airliner, the De Havilland Comet 4 and 4C long-haul jet. But these orders were cancelled when the airline recognised it was moving too fast. The airline was not making the profit it expected despite the amazing success of the Viscount which flew three quarters of the airline's seat-miles. It could not survive in competition with the 'big four' airlines and the rulings by the CAB which limited it.