" When QBI conditions are declared for Croydon, only one aircraft is permitted to enter the zone at one time. The aircraft proceeds towards the aerodrome receiving guidance from the controller. He signals 'Motors North', or 'Motors South' e.t.c as appropriate. The pilot thus modifies his heading until the signal 'Motors Overhead' is received. The pilot then turns downwind, and after an appropriate time, turns through 180 degrees. He then commences a letdown at an appropriate rate allowing for wind conditions to be able to land at the aerodrome. Pilots rarely attempt such a manoeuvre with a cloudbase less than 100 feet."
I quote this roughly from an aeronautical encyclopedia of about 1938 which gives full details of the operation of the Short-Mayo composite amongst other things.
Anybody fancy landing their 747 this way on the grass at Croydon with a 100' cloudbase? I assume that the legendary Capt. O.P. Jones of Imperial Airways did this in his HP 42 every day!
P.P.