IFR Weather, Minimums and Alternates

Alternate requirements

File an alternate unless weather at ETA is at least 2,000 ft ceiling and 3 SM visibility (1-2-3 rule) and appropriate approaches are available. If an alternate is required, forecast must meet 600-2 for precision or 800-2 for non-precision at the alternate.

Takeoff minimums

Part 91 operators may depart with zero-zero unless airport or OpSpec requires higher minimums. Part 121/135 have standard takeoff minimums. Know departure procedures and obstacle clearance.

Weather products for IFR

• TAF — aerodrome forecast for planning.
• AIRMET Sierra (IFR/MTN OBSCN), Tango (turbulence), Zulu (icing).
• SIGMET — significant weather including convective activity.
• PIREPs — actual icing, turbulence and cloud tops.

Personal minimums

Build margins above legal minimums for experience level, equipment and terrain. Consider fuel, icing, wind and single-pilot workload in go/no-go decisions.