DALLAS — Today, in 1948, Philippine Airlines (PR) began its first transpacific sleeper service between San Francisco, California, and Manila.

The airline, formally incorporated in 1941 by a group of businessmen headed by Andrés Soriano, is the flag carrier of the Philippines, operating from its base at Ninoy Aquino International Airport. Its first transpacific sleeper route was operated using a Douglas DC-6 airliner.

The carrier is the oldest airline in Asia operating under its original name.

Transpacific Flights

The Pacific was bridged commercially by Pan American before the Atlantic was. The only commercial service attempted across the Atlantic beforehand was by the Zeppelins.

Transpacific flights span across the Pacific Ocean from Asia or Australia to North America, Central America, or South America, or vice versa, and usually have been made by fixed-wing aircraft.

By the end of the 1950s, aircraft innovations were bringing a new level of speed, comfort, and efficiency to the traveling public. However, transcontinental travel needed to innovate; it was the dawn of the jet age.

Thus, as flying became commonplace and jet aircraft began to replace piston-engine airliners such as the DC-6, flying was no longer a novelty; it was becoming a necessity.

The Piston-powered Douglas DC-6

Philippine Airlines operated the Douglas DC-6, a piston-powered airliner and cargo aircraft built by the Douglas Aircraft Company from 1946 to 1958, to service its maiden trans-Pacific flight.

In 1948, The newly acquired DC-6 enabled PR to reduce the trans-Pacific crossing to 30 hours from 41 on the DC-4, by eliminating Kwajalein and making stops only at Guam, Wake, and Honolulu.

The aircraft’s origins date back to the end of WWII when it served as a military transport. To compete with the Lockheed Constellation in the long-range commercial transport market., the type was reworked by Douglas.

Douglas Aircraft modified the design into a civil transport 80 in (200 cm) longer than the DC-4. The civil DC-6 first flew on 29 June 1946, being retained by Douglas for testing. The first airline deliveries were to American Airlines (AA) and United Airlines (UA) on 24 November 1946.

A series of inflight fires, including the fatal crash of UA flight 608, grounded the DC-6 fleet in 1947. The cause was found to be a fuel vent next to the intake of the cabin cooling turbine; all DC-6s were modified, and after four months on the ground the fleet was flying again.

More than 700 were built and many still fly today in cargo, military, and wildfire control roles.

The End of the Sleeper Service

As aircraft became faster and passenger numbers increased, airlines discontinued their lustrous sleeper service in the 1950s. Expensive to operate, sleeper service gave way to low-fare night coach service.

It is around this time when the coast-to-coast eastbound flights became known as “red-eye” specials.

Passengers began to experience physiological problems as they crossed several time zones within a few hours. Shortened or prolonged days or nights upset the natural rhythms of the body and made sleeping difficult.

Later dubbed “jet lag,” this was experienced for the first time after long-distance trips on fast piston-engine and turboprop aircraft.

The featured image shows a Philippine Airlines Douglas DC-6.