Instrument Flight Rules (IFR) apply for when it's too foggy: Less than 3 miles visibility and a ceiling of 1000 ft above ground. When you are on an IFR flight

Instrument Flight Rules (IFR) apply for when it's too foggy: Less than 3 miles visibility and a ceiling of 1000 ft above ground. When you are on an IFR flight plan and comms fail you stick to your flight plan if still in the clouds and arrive at various point at the time you are expected. Priority during comms failure is landing in good weather if able. Radar failures happen and there are times when you need to do position reports.