Frank Whittle is credited with the invention of the jet engine purely on the basis of his identification of "acoustic" thrust technology! Some reports attribute him as stating "as static thrust disipates acoustic thrust increases and the increase is sufficent to conterract the total loss of static thrust at higher air speeds"
Purists of this theory often cite the Concord is the pinnacle of acoustic thrust development however others are adamant the BN Islander should hold this unique place is history.
Stage 3 noise restrictions resulted in a decline in this field of engineering however it is rumoured that RR had a secret development program in operation. Of course that may explain some of the engine problems the A380 has faced.
VTIC