NavList:

The Sky Beyond, an autobiography of the astounding Australian pilot Sir Gordon Taylor, 1896 - 1966, came my way.

He was co-pilot /navigator of the crew that flew the Fokker Trimotor Southern Cross from Oz to NZ, pilot of the Lockheed Altair that crossed from Oz to Africa, and captain of the PBY Catalina which first completed the route across the Pacific via Easter Island to Valpariso, amongst  many other astonishing pioneering flights. He described most eloquently the techniques used to navigate huge distances and find islands never before visited by aircraft.

To summarize, when no other aids were available, navigation was by finding wind using double drift sights, and bubble sextant CN to confirm track and/or speed. CN was frequently complicated by the inability of those aircraft to climb above weather, and the usual rain over tropical islands or atolls. He could read the sea-level wind from the air better than Chichester, and prefered cross track accuracy over time.

Equally demanding was the then relatively poor aircraft performance, and lack of runways, requiring beach take-offs for overloaded land planes, and rocket assisted take off for the PBY. Cruise speeds of only 90kts meant flight durations of up to 30 hours for the PBY. Those aircraft could not fly if any engine lost power early on, before fuel was burnt off. Engines were at max sustainable power, and prone to failure, and oil could run out before fuel. He had more trouble with oil than navigation.

Radio homing did not work. Morse was needed to communicate on HF, and night landing flares (goose-necks) had to be ordered in advance.

The epitome of piloting and navigation skills, and bravery.