INSTRUMENTS FLIGHT PLANNING
FIGURING FUEL MINIMUMS
OPNAVINST 3710.7 states that all flights in Naval aircraft shall comply with certain minimum
fuel requirements. The specific requirement depends on whether an alternate airfield is required
The jet log is a preflight tool which determines, before your mission, the minimum fuel required
for that particular flight. There are two examples that we will discuss:
Instrument flights with an alternate required.
Instrument flights with no alternate required.
Because of the unforeseen elements of aviation, headwork dictates considering an alternate
regardless of prevailing weather conditions.
The preflight mission completion fuel computation for instrument navigation flight is relatively
simple. It is the sum of the fuel required to fly from the destination IAF to the alternate IAF,
plus the amount of fuel for one approach, plus OPNAVINST 3710.7 reserve fuel requirements.
With an alternate required, OPNAVINST 3710.7 dictates that your fuel total is at least equal to
the sum of the following:
Flight from T/O to destination IAF.
Flight from destination IAF to alternate airfield.
OPNAV reserve fuel.
With no alternate is required, the fuel becomes the total of:
Flight from T/O to destination airfield.
OPNAVINST 3710.7 reserve fuel.
Now to analyze the various parts of the OPNAVINST 3710.7 fuel requirements:
Flight from T/O to destination IAF includes all planned fuel requirements from T/O,
including climb and cruise to destination IAF.
2. Flight from destination IAF to alternate airfield is your planned fuel requirements from
alternate profile #1 of your jet log.
Fuel for OPNAVINST 3710.7 reserve is calculated as follows:
10% of planned total fuel requirements, or
6-2 MISSION COMPLETION FEASIBILITY