Figure 4-5. Forecasted Weather

INSTRUMENT FLIGHT RULES WORKBOOK

CHAPTER FOUR

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