There's a nice bit on page 35 of GADIL June 2003:
"while GPS must not be used as a primary means of navigation..."
Does anyone have a reference for this piece of "law" ????
As far as I know it is complete nonsense. The ANO specifies what equipment must be CARRIED in certain circumstances and clearly when doing e.g. an ILS one is supposed to use the ILS receiver to track the ILS... but what about a BRNAV-approved GPS at FL95+ which is supposed to be completely legal though somewhat moot in the UK since one needs to carry all the old kit anyway to do an IAP somewhere...