INSTRUMENT FLIGHT RULES WORKBOOK
The following chart can be found in OPNAV 3710.7 and is to be used by Navy/Marine Corps
pilots when determining alternate weather requirements.
Figure 4-4 OPNAV 3710.7 (Figure 4.1)
Figure 4-5 Forecasted Weather
When the destination weather is forecasted to be below the lowest approach minimums you can
use (in other words, your destination is "below minimums") you must find an airfield within your
aircraft's range that has weather forecasted to be at or above 3000 foot ceiling and 3 miles
visibility (Figure 4-5). This airfield will be listed as the alternate on your IFR flight plan.
The "lowest approach minimums" at your destination will depend on the navigational equipment
installed in your aircraft and the type of approaches available at the destination. PAR and ILS
approaches have the lowest minima of all published instrument approaches. You must consult
the appropriate Low Altitude Instrument Approach Procedures Volume to determine if your
destination has a PAR approach and the approach minimums. The only equipment required in
the aircraft to make a radar approach (PAR/ASR) is a two-way communications transceiver.
INSTRUMENT FLIGHT RULES 4-7