A little further info on water/watermeth injection. On the RR Dart the water meth was injected into the first stage compressor,the methanol burned in addition to the fuel in the combustion chambers to keep the temperature up.On the RR Spey the de - min water was injected to the rear of the compressors and the CASC unit (just a fancy name for the FCU.)was uprated in wet mode to increase the fuel flow. I once observed a watermeth power check on a Viscount where the supervisor performing the engine run forgot to switch the pump on and at max dry power he reached over and switched it on - the result was a tremendous roar and the engine wound down with water meth pissing out the intake and exhaust, the water meth control unit would have been trying to restore the power but having no flow would have been wide open so basically poured so much in it put the fire out. No immediate damage was done but i often wondered if the thermal shock had any consequences.