Fuel System and Fuel Measurement - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 67

trip fuel including

climb cruise descent approach climb

f u e l f o r

from TOC
to TOD for
cruise climb
and descent

initial climb,
climb to TOC

from TOD
to IAP

from IAP
to 15 m

climb

based on expected weather conditions

departure
routing

AT S
routing

arrival
routing

runway

Fig. 4.7 Fuel for an altitude of 1,500 ft (457 m) to the destination

• Alternative fuel, that is required from destination to alternate airport, except in
case of island operation;
• Final reserve fuel, which has to be enough for 30 minutes holding above an
alternate airport at least (in the case of jet aircraft);
• Additional fuel, as when required by special operations such as Extended-range
Twin-engine Operation Performance Standards (ETOPS) [ 35 ]; and
• Extra fuel, an amount that the flight dispatcher or the pilot in command seems
desirable when a period longer than the planned flight time is probable because
of prolonged delays or when mandatory rerouting is expected in-flight on the
ground due to traffic congestion or weather deterioration.

The sum of the above quantities is called block fuel or fuel at brake release.
Fuel items are mandatory by national codes. The one exception is the extra fuel,
which is optional and left to the dispatcher's or pilot's discretion.