T-45A UJPT & E2-C2 INAV08
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.
The PAR minimums are 100-1/4 and your absolute
minimums of 200-1/2 are within the forecast range
of 300-1. 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 one
published 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 of700-1 3/4
(400-3/4 plus 300-1) to be an acceptable alternate.
Example C
IFR Filing Criteria
ALTERNATE WEATHER
DESTINATION WEATHER
ETA plus and minus one (1) hour
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 3,000-3 (single-piloted
NON-
PRECISION
absolute minimums 200-1/2)
PRECISION
PAR
ILS
* Published
* Published
Published
minimums
minimums
minimums
plus 300-1
plus
plus
200-1/2
200-1/2
3,000-3 or better
No alternate required
*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
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