How many NDBs are there in the UK?
Well, how many are there?
Plus, imagine you fly directly North from Heathrow, using, the Heathrow NDB (HRW) to maintain a Northerly track (let's suppose it's switched on and really powerful). Next, you intercept the Manchester VOR (MCT) 090 radial, and turn West to track towards it. Over what range of hills are you making the turn?