Figure 1-34. OPNAV 3710.7 Determination of Requirement for Alternate

METEOROLOGY FLIGHT PLANNING

CHAPTER ONE

the flight planning process. In particular, when filing an IFR flight plan, an alternate landing

airfield may or may not be required to be included on the DD 175 Flight Plan.

Naturally, the OPNAV 3710.7 provides rules that determine when an alternate is required, as

pictured in Figure 1-34.

Figure 1-34 OPNAV 3710.7 Determination of Requirement for Alternate

When filing a Navy IFR flight plan, an alternate is required if the destination is forecasting a

ceiling below 3000 feet or if the visibility is less than three statute miles (referred to as 3000-3)

for the time period of +1 hour of the planned ETA. If the forecast ceiling for the destination

airfield is "below minimums," then an alternate must be selected that has VFR weather, 3000-3,

or better. However, if the destination has ceilings above the minimums but below 3000-3, then

the alternate airfield must have forecast ceiling and visibility above the minimums for the

planned approach by the appropriate margin (indicated on the right of Figure 1-34), either 300-1

for a non-precision approach, or 200-1/2 for a precision approach.

AFI 11-202 (Vol. 3) provides rules determining when an alternate is required, as pictured in

Figures 1-35 and 1-36, depending on whether flying fixed wing or rotary wing aircraft.

AVIATION ROUTINE WEATHER REPORTS AND TERMINAL AERODROME

FORECASTS 1-29