Eye in the sky:
Thanks, I like where you are coming from!
I just happen to work & fly at well equipped airfield....have never actually had to go and count the lights at 60m spacing...yet!
On the occasions we have lost the transmissometers, and it's always in the middle of winter, we have to have good vis for hours to re-calibrate. Remember we lost a flight on Christmas day once because we could not give a midpoint value!!
Point taken about going round from the MAPT. And no, if on an ILS, I think friends in the tower would be apoplectic if they noted me at 600' at 4 DME
