Who closes an airline's IFR flight plan and when?

Question

ATA (Air Transport Association of America) defines the various flight phases (ATA Spec 2300, flight phases). The last phase is called Flight Close and is described as "The Flight Close phase begins when the crew initiates a message to the flight-following authorities that the aircraft is secure [...]".

In commercial airline operations, who closes the IFR flight plan? The flight plan is usually filed by the dispatchers, I guess. I have never heard a pilot actually close the flight plan before leaving the aircraft...

Answer 1

When landing at a controlled aerodrome, air traffic control will automatically close the flightplan once the flight has safely arrived. The pilot does not have to do anything in this case. The majority of commercial flights take place at controlled aerodromes, which is probably what makes you think that pilots never close their flightplans.

If landing at an uncontrolled field (that is, one without a control tower), however, the pilot will either close the flightplan by contacting a nearby ATC station on the radio before landing, or via telephone after landing.

This applies equally to IFR and VFR flightplans, to big passenger jets and small one-person GA aircraft. If the destination airport — any airport of any size — has an operating control tower at the time of arrival, they will close your flight plan. If the airport does not have a control tower, or the tower is closed at the time, you have to contact another ATS unit to have it closed.

This is actually very logical when you think of it. When you are on a flightplan, you are automatically provided with alerting service. Meaning that if you do not arrive on time, people will start looking for you. If you are landing at an aerodrome with a control tower, the tower is responsible for your alerting service. They have your ETA (based on your FPL EET and ATD) and will initiate a search and rescue operation if you are late. If flying to an uncontrolled aerodrome, some other ATS unit (for example an area-wide flight information service) is responsible for your alerting service, so they are the ones who need to initiate search and rescue if you do not arrive on time.

Now think of this: if landing somewhere with a tower, the tower obviously knows when you land (they clear you to land, after all, and their job is to look at the runway). Thus, the tower knows that you have landed safely and that alerting service can be cancelled.

However, if landing somewhere without a tower, where another unit (not on-site) is responsible for making sure you land safely, how would they know that you have landed? The only way to be sure is for you to call them up on the radio or telephone to let them know that you have safely arrived. They will then file the arrival time to note that you have arrived safely and no search and rescue needs to be initiated.

And this is essentially what "closing a flightplan" is - it actually just means that your arrival time is sent to whichever unit is responsible for your alerting service. It's not that your flightplan is actually "closed" or "deleted" from some system, it just means that your arrival time is filed so that everyone knows the flight has landed.

Answer 2

In the interest of completeness...

expeditedescent's answer correctly describes the effects of the flight-plan closure system. But at least in the USA, the actual mechanics are different.

I had confusion about this as well. The terminology used (by the FAA and others) is that controllers will close a flight plan "automatically" if the aircraft lands at a towered airport, and if the flight lands at an untowered airport the closure is not "automatic."

In fact the inverse is true. Whenever a flight drops off of radar it will go into a "coast" status where the system will keep pushing it along for a few moments based on its last known groundspeed (coasting) and the flight number will show up in the "coast list" on the controller's scope.

If the aircraft's transponder is recognized again within a minute or so, the flight will be taken from coast status back to active status. This might happen if someone was doing a touch-and-go, or made a missed approach, or if they were flying just at the right way to be tangential to the radar site for a moment and thereby dropped from coverage.

If the transponder is not recognized again within the right amount of time, the flight will be dropped from the coast list and a message will be sent to the main flight data processing computer to remove the flight plan from the system. This is what happens automatically, at both towered and untowered airports, unless the controller takes a positive action to prevent it from happening (which they will do, for IFR flights arriving at untowered airports).

The controller will preserve the flight plan in the system, and if they are using flight progress strips they will preserve the strip, until they hear from a trusted source that the aircraft is safely on the ground. Usually this will be the pilot, but it could be airline operations or even the FBO or county sheriff in the case of a general-aviation IFR flight. Only once they know the aircraft has landed will they let it be removed from the system. If they don't get that confirmation they will initiate search-and-rescue operations.

There is another option: the pilot can elect to cancel their flight plan in the air before they reach the airport and proceed under visual flight rules. Generally airlines' procedures will not permit them to do this, but general-aviation pilots will often cancel in the air.