My earlier caution to Bob Viking was not meant to signal open warfare between the various types of 'drivers airframe', 'directional consultants' or anybody else but clearly it has fired the combative ppruners to take to the barricades.
I must search out a Christmas card received many moons ago which had a photo of Avro's tin triangle with a Blue Steel tucked underneath, on the front. When opened, the card held the message: 'Peace on earth and goodwill to all men - From the RAF's nuclear strike force'.
O-D