Figure 3. Destination/Alternate Weather Examples -- Situation 2

T-45C TS INav-08

Fuel, Weather, and Alternate Airfield Planning

SITUATION 2 - DESTINATION FORECASTING

ABOVE PUBLISHED MINIMUMS BUT BELOW 3,000-3:

Assume you are single-piloted and NAS Pensacola is forecasting weather of 300 ft and 1 sm for the period one hour before until one

hour after your planned ETA with surface winds of 090 degrees at 5 kts. The forecast weather is above the published PAR minimums

of 100-1/4 but below 3,000-3; therefore, you must plan an alternate destination. You have selected NAS Jacksonville as your alternate

with forecast winds of 090 degrees at 5 kts. Due to a mechanical failure, you do not have the option of using an ILS approach; however,

TACAN and VOR/DME are available.

Example C

Even though the PAR minimums are 100-1/4 and your absolute minimums of 200-1/2 are within the forecast range of 300-1, you need

to examine the criteria for available non-precision and precision approaches at your alternate airfield. The ILS criteria do not apply in

this situation for two reasons: 1) ILS is not available at NAS Jacksonville, 2) your ILS equipment is inoperable. You need to examine

the criteria for available non-precision and precision approaches at your alternate airfield.

Also remember that should there be more than onepublished approach to the probable duty runway at your alternate, you would use

the non-precision approach with the lowest minimums for planning purposes. In this situation your most suitable approach for planning

purposes is HI-TACAN RWY 9 with minimums of 400-3/4. Therefore, NAS Jacksonville must have forecast weather of 700-1 3/4

(400-3/4 plus 300-1) to be an acceptable alternate.

IFR Filing Criteria

ALTERNATE WEATHER

DESTINATION WEATHER

ETA plus and minus one (1) hour

0-0 up to but not including

3,000-3 or better

published minimums

Published minimums up to but

not including 3000-3 (single-piloted

NON-

PRECISION

absolute minimums 200-1/2)

PRECISION

PAR

ILS

* Published

Published

minimums

plus 300-1

plus

200-1/2

No alternate required

3,000-3 or better

*In the case of single-piloted or other aircraft with only one operable UHF/VHF transceiver,

radar approach minimums may not be used as the basis for selection of an alternate airfield.

Example D

Figure 3: DESTINATION/ALTERNATE WEATHER EXAMPLES -- SITUATION 2

(2-02) Original

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