Early morning at Croydon Airport. The flag being raised, the terminal entrance a hangar. Long shot of the airport buildings. Cleaning the buildings and opening up the kiosks and airline desks. The Meteorological bureau: a man releases a weather balloon, while another observes its direction through a theodolyte. Commentary explains that the bureau is in touch with local and foreign weather stations. A table of the weather symbols. A man changing small plates which hang on the weather board in the main hall, showing conditions every hour.

A Handley Page 42 seater, on a SW continental route, emerging from an Imperial Airways hangar . A Fokker 12 emerging from a Sabena K.L.M. Hangar. Early morning inspection of a Handley Page: men checking the engines, propellors, cleaning the wheels and loading with catering supplies. A mobile tanker filling up for the day's work. CU of a man preparing the hose. MS of two Handley Page aircraft, which have been certified for 24 hours service. A Handley Page is towed toward the embarkation point.

Passengers arriving at the airport. Aircraft engines being started. Cargo, baggage and Royal Mail being loaded onto a Handley Page Heracles while passengers have their passports examined. Passengers and crew boarding. The aircraft is signalled, taxis out and takes off. A map of Europe and the eastern hemisphere showing the routes the Heracles will take via Cairo to Cape Town and Brisbane. A K.L.M. Fokker 12 being refuelled by a mobile tanker .

The aircraft taking off and in the air. A map showing its route, via Amsterdam to Batavia. A Lufthansa Junkers taking off. Map showing its route to Berlin. A Swiss Air Douglas taking off. Map showing its route to Zurich. The K.L.M. Fokker 12 in flight, CU of the pilot, and the ground. The aircraft radio operator using morse code . In the control tower, the operator pinpoints the aircraft's position using flagged pins. The aircraft in flight. A Handley Page 42 approaching Croydon. Their position is received over the radio by the flight controllers. An explanation of how they find the aircraft's exact position by using a goniometer and taking bearings from two other stations. A map showing the different airline routes converging on London. Aircraft from Air France, Swiss Air and Lufthansa landing. A Handley Page Horatius circling the control tower and landing. Passengers, baggage and mail disembarking. The Customs department.

A Handley Page Heracles in a hangar; commentary explains that periodically an aircraft is completely dismantled for a thorough inspection of the wings and engines . An engine being hauled into a workroom, where engineers are shown removing the cylinders and piston. CU of the removal of the crank case and crank shaft with piston rod. Cleaning the components. Grinding in a new valve after cleaning. An inspector checking the cylinder. The crank shaft going through the same process of cleaning. The component parts of the crank shaft being tested for wear. The engine being reassembled. Engineers studying an RPM meter as the engine is tested in a wind tunnel . In the hangar, the riggers replace the engines and propellors. A long view of the airport building with various small biplanes in the foreground. Lights coming on in the control tower as darkness falls . A Handley Page aircraft coming in to land. A wind sock.