Pub User, I think the RAF operated both the 1A's and the 600 series, both powered by RR Vipers. I think they were called the Dominie. The system I mentioned was fitted on the 700A and B series, both powered by the Garrett TFE731's. The 1AR's and the 400R series were retrofitted with the same engines but had no need for APR, since they weighed about 5000 lbs less than the 700.
