A Complete Manual for Conducting International Flight Operations

ETP Review & FMS ETP Entry

ETP Review and FMS ETP Entry

After ETP’s have been calculated using manual, online or 3rd party calculations the ETP’s shall be constantly evaluated for viability based on current/forecast weather and NOTAM’s. For ACI Jet crewmembers it is recommend that ETP alternates are always at or above alternate airport weather minimums, which entails adding 400’ and 1 mile to the MDA or DH for airports with one straight-in approach and adding 200’ and ½ mile to the highest MDA or DH and ½ mile visibility to the higher authorized landing minimum for airports with at least two operational navigational facilities, each providing straight-in approaches to different suitable runways. It is worth mentioning that in some cases the alternate minimums for airports with one navigational aid may be lower, and may be used.

ETP Fuel Calculation

The fuel for the ETP’s shall also be evaluated, in most cases the ETP fuel will meet or exceed the trip fuel plus reserve fuel. For example, on a flight from KSBP-PHOG the following fuel and ETP summary is calculated.


The above is the fuel required for the flight, which does not take into fuel required to reach ETP airports from the ETP point. In the above example, if the aircraft departs with 20,000 lbs of fuel the fuel required to reach the destination is 13,828 lbs. reserve fuel is calculated as 4,000 lbs. so additional fuel remaining is 1768 lbs. In looking at the ETP summary, usually the pressurization ETP will be the most limiting and will have the highest fuel required.

ETP Summary

 In the ETP summary above the fuel required to reach the ETP waypoint and return or continue requires (8,063+9,770) 17,833 lbs. If the aircraft departs with 20,000 lbs of fuel, that will leave a reserve of 1,767 lbs of reserve after taxi fuel.


As seen in this example the total trip fuel with reserve is 17828 lbs. and the ETP depressurization fuel required is 17,833 without reserve. It is therefore recommended practice that ACI Jet crewmembers carry enough fuel to meet the greater of either the trip fuel plus reserve or the ETP fuel plus a marginal reserve. It is the pilots discretion as to what “marginal reserve” they choose to apply as this is not regulatory in nature, but the reserve shall consider the availability and weather at alternates, instrument approach procedures, NOTAMS, runway lengths, etc.

ETP Considerations

When evaluating the reserve fuel required for the ETP waypoints there are several important factors to note. Most 3rd party flight planners will instantly transport the aircraft from cruise altitude to the drift-down altitude or depressurization altitude. What this means to a pilot is the fuel saved during the drift-down procedure or emergency descent will provide additional fuel over the fuel calculation indicated in the 3rd party flightplan. It is important to know how your flight planning system will calculates fuel in the event of a drift-down or emergency descent. It is also important to note that the depressurization  will usually be the most limiting of the three ETP calculations.


Revision date: July 29, 2015

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