Its a good question. In the NATS videos about the London TMS Irv Lee has the quarter mill while the pilot (sorry I forgot the name) has the half mill. At numerous points Irv says that the quarter mill has relevant detail which is not seen on the half mill.
Up until recently I always used the half mill charts. However I've become drawn to the quarter mill and haven't quite decided whether they're a help or just confusing me! I have the Aware GPS and had the battery go dead (didn't realise the cig lighter plug didn't work) within 5 miles of Luton controlled airspace. Caught me unawares and I panicked - which didn't impress my passenger much, especially when I had to take both hands off the control yoke ("steering wheel") to reset the GPS!
Instantly learnt that
a) Don't panic if unsure of position. I turned a few degrees so make sure I wasn't heading for controlled airspace. Farnborough North asked for my position as I had forgotten to turn the transponder back on. As soon as it was on they gave it too me. I found the power Monkey - reset the unit and when the GPS came back on I was exactly on track. (No brownie points for good airmanship that day!)
b) Do your route planning as if you didn't have a GPS. Have lots of waypoints and keep track of times.
c) Much more fun following railway lines, roads and coast lines then the magenta line on the GPS.
Last edited by Molesworth 1; 19th May 2010 at 13:29.