Flying ASI to MPA in 1987/8, only useful navaid on the Herc was Omega, one of the aerials for which was/is in Argentina. To check on this the nav took a sun line every 30 minutes. So as the rest of the crew slumped into a bored coma, the nav worked quite hard. Just to help, at the time the flight was normally scheduled for, the sun appeared directly behind the refuelling probe, so the aircraft had to turn 30 degrees off heading while the shot was taken.