SETTING UP FUEL & PERFORMANCE

Enter the default values for the settings to be used in calculating the fuel requirements for flights in this aircraft.

Setting	Details
Template	This setting determines the accuracy of the fuel calculations that are possible. The Basic template is available for all users. Turbine aircraft pilots and business users may select the Advanced template, which makes the Advanced Data option visible.
Fuel Type	Select a fuel type from the options available for your aircraft model.
Units	Select the units of fuel flow (consumption) from the options available: gallons per hour (GPH), litres per hour (LPH), pounds per hour (PPH), and kilogrammes per hour (KG/H). Note: If you are using the Advanced template, make sure the units selected here match the units in the Advanced Data tables.
Max Fuel	Enter the maximum fuel capacity of the aircraft.
Default Initial Fuel	Enter the normal quantity of fuel onboard the aircraft before a flight.
Taxi Fuel	Enter the quantity of fuel normally carried for taxiing (this can be modified for individual flights depending on the airport size).
Final Reserve Calculation	Choose whether the reserve fuel is either a Constant value or uses a Time-Based calculation where the reserve depends on the flight duration. This selection will affect the settings which follow. Refer to this online article for further details.
Final Reserve (I/Y/Z) and Final Reserve (VFR)	If the final reserve calculation is based on a constant value (above), enter the quantity of reserve fuel for flights using Instrument/Yankee/Zulu flight rules and Visual flight rules.
Select Power Settings for IFR/VFR Final Reserve and IFR/VFR Final Reserve	If the final reserve calculation is time-based (above), select the flight mode to use in calculating the final reserve. Then select the number of minutes at either the default altitude or in cruise mode for which reserve fuel is required. Complete these selections for flights using both Instrument and Visual flight rules.
Contingency Fuel Calculation	This is extra fuel to be carried in case of unforeseen weather conditions or calculation errors. Enter the minimum contingency fuel criteria as one or more of: 1. a percentage of the flight's total fuel requirement; 2. the fuel required for a fixed holding time based on the aircraft's performance data; 3. a fixed amount of fuel; and 4. a reduced contingency percentage of the flight's total fuel requirement if this has been approved by the relevant authorities. The software uses the largest of the values specified in its fuel calculations. If required, enter similar contingency fuel criteria for reaching the alternate (the reduced contingency option is not applicable). Note: If two alternates are included in the flight plan, only the contingency fuel to the furthest alternate is carried.
ALT Contingency Fuel Calculation
Min. Diversion Fuel	If preferred, enter a minimum amount of fuel that must always be carried to allow for diversions. This will be used in fuel calculations if it exceeds the Alt Contingency quantity selected previously.
Approach Fuel	Enter an extra quantity of fuel to allow for manoeuvring on the approach to the destination.
Missed Approach Fuel	Enter an extra quantity of fuel to allow for a complete missed approach procedure at the destination.
Min./Max. Fuel Calculation	Choose whether to calculate the minimum and maximum fuel requirements using the current loading or the aircraft's maximum permissible take-off weight. Only select Use max. take off mass/weight if you want to know the maximum permissible payload for the flight. To obtain the correct weight and balance (W&B) calculations for the flight, always select Use current loading.
Holding Fuel [mins]	Enter the default holding time in minutes for which fuel must be allocated, and use the checkbox to select whether this is included in the minimum required fuel for the flight (this changes its position in the fuel table). Note: The label name for this fuel quantity can be edited to comply with specific regulations; the new label is then used throughout the software.
Extra Fuel	A quantity of extra fuel can be carried at the pilot's discretion or to comply with specific regulations, by selecting the Manual or Max. Off Block Fuel scenarios in the flight planning menu. The label shown for this quantity in the fuel table can be edited here. Use the checkbox to select whether this is included in the minimum required fuel for the flight (this changes its position in the fuel table).
Default STAY Profile	(Aircraft with Advanced Data only.) Select the default flight profile to use in calculating fuel requirements for STAY stages in a flight plan.
Manual Endurance Profile Selection	(Aircraft with Advanced Data only.) Check this box to override the default calculation for Endurance and select a flight profile manually.
Endurance Profile	If the Manual Endurance Profile Selection option is checked, select the flight profile to use in calculating aircraft endurance from the drop-down list. The Most Economical option uses the lowest fuel flow value from all profiles.

Basic Data

If the basic aircraft template is selected, or if no advanced data tables are available for the aircraft, then the figures shown in the small table are used in the fuel calculations.

Select a Stage of Flight from the drop-down list to view the fuel flow rates, rates of ascent or descent and true air speed used in the calculations.
Only two scenarios are given, for low and high altitudes. You can edit these values as required using the information in your Pilot's Operating Handbook (aircraft manual).

Using the basic data for fuel calculations is sufficient if you are well within your aircraft's range and fuel capacity is not a concern, so precise calculations are not essential. However, it is still important to check that the values you enter are correct because they are used to calculate the flight duration and endurance.

Advanced Data

Selecting the advanced aircraft template gives access to extensive tables of fuel flow data for numerous scenarios of altitude, temperature, aircraft weight and flight stages. This option gives much more accurate fuel calculations, which is important if you are operating a commercial fleet or planning flights that are closer to the flying limits of your aircraft.

Click View/Edit to open the Advanced Data screen.

You must save the aircraft before you can access advanced data.

If the software provides comprehensive fuel flow data for your aircraft model, these are listed in the tables.

Select the Stage of Flight, Power Settings and Weight from the drop-down lists at the top of the table.
To view the data at all International Standard Atmosphere (ISA) temperatures, click Show All.

The data can be edited by the user (if they have permission to do so). However, it is often safer to request the technical support team to make extensive changes to advanced data tables due to their complexity.

To add further fuel flow data:

Click Manage List & BIAS above the Power Settings drop-down list.
A dialog is displayed listing the current power settings available for the selected flight stage.
Click +Add More and enter a new power setting name in an empty row.
Check the Default box for the setting you want to use normally.
Click Apply to save and apply the changes in the table.
Click + next to the Weight drop-down list.
Enter a weight in the dialog and click Add.
A new table will be displayed which can be completed with the fuel flow data for the new power setting and weight.
Click the grey + button on the right side of the table to add further rows for more flight levels.
Click Save in the top right of the screen to save the new aircraft data and return to the list of aircraft.
OR
Click Back in the top left of the screen to return to the aircraft setup menu.

You can check if your software supplier holds advanced fuel flow data for your aircraft, or restore the default data after it has been edited:

Click Load Data.
A dialog is displayed.
Click Default.
When prompted to restore default data, click Yes.
The default data set will be restored if possible.
If the data set is not available, a message advising you to contact your supplier will be displayed.
Click Close.

Modifying Advanced Data

The support team can check the advanced data for your aircraft and add missing values or make amendments as necessary, if you send them the Pilot's Operating Handbook (aircraft manual).

Note: Depending on the support team's workload, this can take up to two weeks to complete.

Adding Bias to Aircraft Performance

To reflect changes in performance as an aircraft engine ages or is modified, a bias option can be used to apply a correction to fuel flows and true air speed in an advanced performance template.

Note: This option is only available on request; contact your sales team.

Go to the Advanced Data screen for your aircraft.
Select a Stage of Flight , and then click Manage List & BIAS above the Power Settings drop-down list.
A dialog is displayed listing the current power settings available for the selected flight stage.
Enter a positive or negative percentage in the BIAS TAS and BIAS FF columns for the appropriate power setting(s).
Values can be in the range -99.99 to +99.99.
Click Apply to close the dialog and save the bias settings.
Repeat this for each of the stages of flight used by your aircraft.

Refer to this online article for further information.

Endurance

Endurance is an estimate of the flying time that remains for an aircraft at any point during the flight, to allow the search radius to be decided if contact with the aircraft is lost. There are many methods for calculating Endurance but they all involve making some assumptions about the aircraft's speed, power settings, etc.

The Endurance is estimated by default as the sum of the following time periods, all of which are calculated routinely during the flight planning activity:

Endurance = Trip Time [from take-off to landing]

+ Destination Contingency Time [added to allow for unexpected weather conditions]

+ Alternate Time [time to the alternate aerodrome]

+ Alternate Contingency Time

+ Final Reserve Time [typically 30-45 minutes]

+ Holding Time [if using busy airports where a delay is likely]

+ Additional Time [any other fuel on board]

+ Extra Fuel / Fuel Flow at final Top of Descent [assumes the aircraft is using fuel at a rate equivalent to the planned final descent of the flight plan]