ForeFlight’s Alternate Advisor simplifies the process of choosing a good alternate airport by providing a list of suggestions to help you narrow your options. Alternate Advisor uses a similar interface to the Route Advisor with a popup window that has a map and a list of airports to choose from.
You can access Alternate Advisor on the Flights view by tapping on the Alternate line near the top of the page. Alternate Advisor’s interactive map shows your arrival at the destination airport, with gray lines connecting the airport to each of the proposed alternates, which are listed below. Tap on each airport in the list to highlight its line on the map.
Each suggestion includes information about the airport and your aircraft’s performance if you select it as your alternate. Wind and visibility information from a METAR, TAF, or MOS forecast is shown on the first line under the airport name, followed by tower and runway information, followed by the list of instrument approach types supported at that airport. To the right of each suggestion are performance results showing how much extra time and fuel would be required to reach that airport from your destination.
ForeFlight uses a number of criteria to narrow the list of suggested alternatives, including distance and fuel range considerations, whether the airport is closed by NOTAM, the presence of available instrument approaches, and forecast weather conditions. Additionally, ForeFlight will prioritize any airport that you’ve previously used as an alternate on flights with the same destination.
You can manually search for an airport not shown in the list by typing its identifier into the Alternate field to add it to the map and display its information above the airport list. Once you’ve decided which airport to use, tap the button at the bottom of the window to add that airport as your alternate. ForeFlight will still alert you if your chosen alternate exceeds your max usable fuel.