This is quite an enjoyable documentary to watch. The opening shot shows the raising of an RAF flag over a building described as Croydon Air Port then shortly afterwards balloons and a theodilite are used to ascertain the weather conditions (on an hourly basis) before aircraft operations can begin. Planes are rolled out from their overnight hangars for a detailed inspection then the mail is loaded, as are the passengers on planes called "Heracles", "Horatius" and the like. Some of the cargo is being routed as far away as Brisbane on Imperial Airways planes that seemed to consist entirely of complex series of wing struts that beggar belief when actually airborne. I believe this was the first documentary made by the Acclaimed British "Shell Film Unit" presenting us with some classic cinematography as some Sabena, KLM, Lufthansa and Swiss Air planes go about their daily business. It also features some air traffic control actuality, and that of an complete engine overhaul that is a far cry from what we are used to 90 years later. It is well worth ten minutes, this.