ETP flight plans in general
Dispatch will compute ETP flight plans for most twin-engine jets without any further configuration, however, we highly recommend you review the aircraft settings prior to Dispatching an ETP flight plan. This section helps you understand how Dispatch computes ETP flight plans and what options are available to customize the ETP calculations.
The scenarios calculated by ForeFlight Dispatch are:
Medical: Aircraft operating normally, but a passenger or crew member onboard needs medical attention. By default fuel to the ETP diversion airport will be calculated using the max speed profile available such as maximum continuous thrust. The cruise profile used for the medical scenario can be changed on the aircraft setup page
One engine inoperative: The aircraft loses an engine and will need to divert using a single-engine. Fuel is calculated at the drift down altitude to ETP diversion airport
Loss of pressurization and one engine inoperative (“Most critical”): The aircraft has lost cabin pressure and an engine and will need to make a diversion. By default, fuel is calculated at 10.000 ft to the ETP diversion airport. If oxygen is available onboard the aircraft, oxygen minutes can be defined in the aircraft profile. When oxygen is available, ForeFlight Dispatch will calculate an emergency descent to the initial level off altitude where the aircraft will cruise for the defined number of minutes oxygen is available. The initial level-off altitude can be defined in the aircraft setup. If not set, 25.000 ft will be used. Then, a descent down to the final level off altitude. The final level off altitude is assumed to be at 10,000 ft by default but can also be customized in the aircraft database.
Beyond the above-described scenario parameters, the following other parameters can be used to customize the ETP calculations:
APU fuel burn - An amount of lbs/kg of fuel burn per hour to account for APU fuel. Added to all ETP scenarios
Anti-ice/Ice-accretion - A fuel burn penalty in % to account for anti-ice systems or ice accretion
ETP Fuel bias - A fuel burn penalty in % that can be used to add further conservatism to the ETP scenarios
Minimum ETP Landing fuel - A minimum amount of fuel in lbs/kg that the aircraft should land with at an ETP Alternate
ETP Holding minutes - The number of minutes for which fuel for holding above the ETP airport should be available. The default used value is 15 minutes.
Computing ETP flight plans
Once ETP/ETOPS airports have been entered, a new line under the fuel section will show additional fuel. If the fuel carried by the flight is already sufficient, the additional fuel will be zero. However, if additional fuel is required to ensure the flight can safely divert on all scenarios, you will see Dispatch add additional fuel to the flight plan. You can view a full breakdown of your ETP information by opening the navlog or briefing package.
The below section provides a breakdown of the options on the Flights Page related to ETP/ETOPS flight plans.
1. ETP/ETOPS Airports Field
Specify airports that Dispatch will use to calculate ETP and ETOPS for the flight. Like the Airport fields in the General section at the top of the Flight Edit view, you can enter the identifiers for each airport or start typing the city or airport name to see a list of suggestions that update as you type. You must specify at least two airports for Dispatch to calculate ETP/ETOPS results.
Once you’ve entered at least two airports, Dispatch calculates the ETP results and displays them on the Route Map. Each airport is shown as a light gray dot on the map, and each ETP is shown as a small gray dot along your route line.
After entering at least 2 ETP Alternate airport ICAO codes in the ETP/ETOPS Airports field, Equal Time Points are calculated using the Stepping Stone Method. Diversion calculations are made between each ETP alternate pair for Medical (at altitude), Depressurization, and One Engine Out.
Medical - is a diversion at altitude.
Depressurization - is rapid descent to predetermined altitude (standard is 10,000’).
One Engine Out - is the failure of one engine with a possible decrease in altitude depending on aircraft performance.
The resulting calculations are shown in the Navlog, and also as dots on the route line in the map view.
Hover the mouse cursor over each ETP dot to see a label with details about the ETP:
|**NOTE**: If the aircraft's ETP has not yet been configured, click the blue "Configure ETOPs for this aircraft" link, or click on the Aircraft page and select the aircraft.|
On the Aircraft page, enter the parameters for the aircraft’s ETP Configuration:
After making the changes, be sure to click the green “Publish Changes” button at the lower-right of the page so that the changes are made available to everyone using the account.
2. ETOPS Button
If your aircraft has been configured with proper single-engine airspeed as well as maximum certified ETOPS distance, the ETOPS checkbox will be available to check.
Once checked, Dispatch will enable ETOPS for the flight plan. When computing an ETOPS flight plan, Dispatch will render ETOPS circles on the map and in the briefing package. The circles allow the Dispatcher to easily inspect if the flight is within its ETOPS certification.
3. PSR (Point of Safe Return) Button
When checked, Dispatch will calculate the most distant point along the route from which the aircraft could return to the departure airport with alternate, reserve, and contingency fuel intact. Dispatch then marks this point on the Route Map as a dark gray dot. The PSR dot is both larger and darker than any ETP dots on the map, to help distinguish them. The PSR dot is the same size as the dots used to mark selected ETP airports, but darker. Hold the mouse over the PSR dot for two seconds to show the helper text confirming that it is the PSR.
The point of safe return is calculated by assuming the aircraft has an engine failure and has to be able to return to the origin point on one engine at the one-engine drift down altitude.
4. SETOPS (Single Engine Turbine Operations)
Dispatch has support for SET-OPS as required to operate single-engine turbine aircraft commercially under EASA regulations. For single-engine turbine aircraft that are enabled for SETOPS (available as a subscription add-on), the ETP/ETOPS section will read as SETOPS instead.
- Enroute alternates - The list of enroute alternates used for the SETOPS risk analysis. By default, Dispatch will search for enroute alternates automatically. To modify the list, disable the Auto-Search checkbox.
- ILS / LOC / RNAV - These checkboxes define what approaches must be available for an airport to be considered as enroute alternate in the auto search. If multiple are selected, the filters are considered as one or the other. As an example, if both ILS, LOC and RNAV is checked, the auto search will search for an airport that has either an RNAV, Localizer or ILS approach
- Minimum runway length - The minimum runway length for an airport to be considered as an enroute alternate by the Auto-Search
Once the SETOPS analysis has been enabled, Dispatch will draw circles around the enroute alternates equivalent to the estimated glide coverage by that airport. The briefing package will include a chart with the same graphics as well as a risk analysis report.