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ETP Scenarios Fields

Note: The following descriptions represent the typical access and privileges afforded to users designated as Dispatch Managers/Supervisors. Users with dispatcher privileges will have limited access to a subset of the screens presented.

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ALC: Enter the appropriate airline code.

ETP SCENARIO NUMBER: Enter the desired scenario number (the is range 1 - 999).

DESC: Enter a brief description of the ETP scenario for the flight plan printout.

NUMBER OF ENGINES: Enter number of engines for scenario, <ALL>, <-1>, or <50%>. This field defaults to <?> Search mode; use the up and down arrow keys to select the desired entry. An entry of <50%> implies the loss of half of the normal complement of engines (for a 3-engined aircraft this is equivalent to the loss of two engines.

UNITS: Enter weight units of measure for all fixed burn entries, lbs <L> or kgs <K>. If this scenario is used for an aircraft calibrated in the alternative units, all fixed fuel burn values will be converted automatically.

TLS/CFSS Check: Used to perform the ETOPS Beyond 180 Minute diversion time calculations leveraging our current ETP functionality. Designate an ETP scenario to be used for determining compliance with the TLS or CFSS time limits. The ETP Policy used during flight plan calculation must include at least one scenario designated for TLS or CFSS. You can modify an existing scenario or create a new one to be used for TLS or CFSS check.

MAIN / INITIAL DESCENT PROFILE: Indicate how the Initial Descent from cruising altitude is to be calculated. The options are: Driftdown <D>, Instantaneous <I>, Fixed <F> or Level Off <L>. The Level Off option is used as an emergency initial descent profile instead of instantaneous descent for decompression scenarios. This will allow the system to actually determine how much fuel, time, and lateral distance is associated when descending to the desired fixed altitude. This will produce reduced ETP fuel requirements. If you select the Level Off option you can enter a Normal and Icing Profile (below the Main field). If these fields are left blank the default values are used. You may be required to generate new performance data to use the Level Off option

ALTERNATIVE: If you selected Driftdown in the Initial Descent Profile field, you will be asked for an alternate method to be used in the case that driftdown performance data is not available for the aircraft in use. The options are Instantaneous <I> or Fixed <F>.

NORMAL PROFILE: Enter a drift down profile name for normal conditions, if blank use STD.

ICE PROFILE:  Enter a drift down profile name for icing conditions. This field allows icing penalties to be applied to the ETP calculation (drift down performance) based on specific speeds and flight levels when icing conditions exist.

Only profiles created by NAVBLUE's flight planning performance team can be entered here. This means that you need to provide specific performance data under icing conditions for the aircraft you use before this feature will work. The standard naming convention for these profiles should be “ICE”.

Ice protection ON/OFF

NFP needs to  know when to use the icing profile. If the ETP stations are highlighted in blue, the ETP burn calculation include penalties for airframe and engine anti-icing as well as refer to the drift down performance table for that iciICng profile to calculate the burn.


Description automatically generated

INITIAL DESCENT PROFILE TIME/BURN/DISTANCE: If you have selected Fixed initial descent, then you will be required to provide values for Time (number of minutes), Burn (fixed burn value) and Distance (still-air, in NM) for the initial descent burn, otherwise these fields will be skipped.

LEVEL-OFF: Enter the method to be used to determine level-off altitude: Driftdown (determined automatically from the driftdown performance data), Maximum (level-off will be at the maximum altitude for which there is performance data considering the weight of the aircraft at ETP, and the level-off cruise profile), or Fixed (user specified).

FL: If you select Fixed level-off in the previous field, you must specify the desired level-off altitude. The default entry is ACX which implies that the value will be read from the ETP F/L entry in the Aircraft Characteristics record.

INCREMENT / MFL Incr Limit: Enter the level-off increment to be used.

This entry only applies to scenarios using “I” (instantaneous” descent) as the initial descent profile as well as FIXED LEVEL-OFF – decompression only. The behavior is such that if additional fuel is required for this scenario, NFP will retry the calculation using performance at the next flight level relying on the increment value entered. In this example, increment is 2000ft (20).

If additional fuel is required at FL100, NFP looks at cruise performance at FL120 and verifies if additional fuel is required for that scenario. NFP continues to look at cruise data at FL140, FL160, FL180, and so on…..up to FL250 until additional fuel is no longer required.

CRUISE PROFILE: Enter whether the cruise level fixed <F> or is climb permitted <C>.

ADDN CRUISE PROFILING: Enter multiple level off altitudes along with a time constraint at each altitude.

MFL: If climb is permitted in the cruise, indicate the maximum flight level to be permitted. The default entry is ACX which implies that the value will be read from the MFL entry in the Aircraft Characteristics record.

SPEED: Enter the cruise speed profile or PLN for same as main route. ACX (aircraft) is the default, and if chosen, the aircraft ETP speed, set in the Aircraft Characteristics WebFOMS screen, is used in the profile. The system will use LRC as the default profile if no speed is set in the Aircraft Characteristics WebFOMS screen.

FINAL DESCENT: Enter either <C> for Calculated or <F> for Fixed as the method for determining final descent burn. NOTE: For the descent from 10,000ft to Landing, The final descent calculation in an ETP scenario utilizes the main route's profile key, not the profile key specified for ETP Cruise in the ETP Scenario. For flights using a Cost Index profile for the main route, single engine performance does not exist; when N-Flight Planning executes the final descent burn based on 1 Engine, but is provided a Cost Index Profile Key which does not contain single engine performance, the software performs a more conservative 2 Engine Cost Index calculation of the fuel requirement.

FINAL DESCENT TIME/BURN/DISTANCE: If you have selected Fixed final descent, then you will be required to provide values for Time (number of minutes), Burn (fixed burn value) and Distance (still-air, in NM) for the final descent burn, otherwise these fields will be skipped.

HOLD TIME: Enter the hold time in minutes (1 - 99).

HOLD METHOD: Enter method for determining hold fuel burn; <C> for Calculate (using Hold performance data tables, <T> for Top of descent (using the fuel flow at top of descent), or <F> for Fixed (use values defined in next field).

Note: If there is no TOD fuel flow (e.g. in the case where driftdown distance is greater than distance from ETP to ETP alternate), the flow is the cruise burn rate at 225 knots using the driftdown altitude/weight/ISA.

FL: Enter the flight level to be used for hold calculations. The range is FL010 to FL250.

HOLD BURN: If you selected Fixed hold burn, enter the desired amount in this field.

APU BURN / Method: Enter method for determining APU burn; <C> for Calculate or <F> for Fixed. Optionally, this field may be left blank. If you select the <C>, the program will use the APU burn rate defined in the Aircraft Characteristics file, multiplied by the total diversion time from ETP to ETP alternate.

APU TIME/BURN: If you chose Fixed for APU burn, enter the desired values for Time and Burn here.

Note: The Time entry has no impact on fuel calculations. It is available only to permit a time figure to be printed on the flight plan if desired

MISSED APPROACH TIME/BURN/DISTANCE: This field is optional. If desired, enter the Time, Burn, and Distance in the appropriate fields.

Note: The Time entry has no impact on fuel calculations. It is available only to permit a time figure to be printed on the flight plan if desired

PENALTIES APPLY TO: This section permits you to define additional fuel penalties to be applied to the ETP calculations, typically for ETOPS purposes. For each category there are three entry fields; the first accepts a numeric value, the second defines whether this entry is a percentage, or a fixed value, and the third field specifies what the percentage amounts are to be based on (Cruise only, Hold only, or Total diversion time).

Additional penalties include:

airframe ice accretion

Enter whether you want to only apply the icing penalty on 10% of the route time. (REDUCE ICE TIME:) <Y> for yes or <N> for no.

engine anti-icing

wind uncertainty 

Enter a percentage for the adjustment in the wind component (WIND SPEED ADJUST). This value increases the wind speed by the percent entered for all fuel burn calculations. Note the value impacts the performance look-ups for ETP diversions, but not the fuel directly. Rather, the value impacts ground speed, which in turn effects the time, and subsequently the fuel burn.

burn uncertainty

180 minute ETOPS


ice penalty percentage - set a specific icing penalty reduction in an ETP scenario. The Ice Penalty Percentage is only applied if Icing Protection is enabled. If it is disabled or set to Ice Protection if Forcasted, the ice penalty percentage is not used. To enable Ice Protection, right click in the Out or In field in the ETP group on the Plan screen and select Ice Protection Enabled. When enabled the field turns blue.

EXTENDED RANGE ENTRY POINT RADIUS: Enter the distance to be use in determining the point along route where the aircraft will enter the zone of Extended Range operations.

REMARKS: Enter any remarks associated with this particular scenario.


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