The problems of detecting and indicating an approaching stall have been investigated in flight on an "Anson" aircraft. A lower-surface flap near the leading-edge of the wing detects the approaching stall at a speed which depends critically on the length of the flap and on its location, but the margin of warning speed over stalling-speed is reasonably independent of landing-flap position and throttle setting. A trailing-edge flap is being developed as a stall detector. A"stick-shaker" is the most acceptable form of stall indicator, and ground tests show that a frequency of shake of about 6 cycles/second is desirable. A practical "stick-shaker" of this frequency has been satisfactorily flight-tested on the "Anson". Further development work is in progress. The College of Aeronautics was founded in 1946 and was granted university status in 1969 becoming the Cranfield Institute of Technology. In 1993 it changed its name to Cranfield University.