The deep stall of sailplanes

Abstract

Recently, a couple of high performance sailplanes crashed in Australia.  The cause...is suspected to be the 'deep stall', the malaise of every high 'T' tail aircraft.... when flying the aircraft with an aft C. G. position...  It is suggested that every 'T' tail sailplane should be tested and testified to have been tested to establish the safe limits of the aft position of the C. G. at which a deep stall would be impossible...