A Hypothetical scenario

A landing aircraft at a busy airport such as London Gatwick LGW has an issue during landing that requires the immediate closure of the runway.

My understanding is that there could be several aircraft lined up on approach to land at busy times and more circling waiting to land.

If such an incident as the one described above were to happen how would ATC handle the other aircraft?

Obviously they will almost certainly need to be diverted, would they contact each aircraft individually to give instructions starting with the closet to landing and work back or is there a quicker way to give mass instructions to divert all aircraft?


As a tower controller, in case of an unexpected unusual situation for an aircraft on final approach, this will be my list of priorities:

  • Clear the runway of other traffic
  • Determine if fire and rescue services need to get involved
  • (Call fire and rescue services)
  • Call approach and ask them to stop inbound traffic. In case of other traffic on final behind the emergency, coordinate missed approaches
  • Instruct other aircraft on final to go around, in accordance with the coordination with approach

The above points will take me no more than 30 seconds to get through. This takes care of the most immediate priorities. I will then await the landing of the emergency plane, and coordinate with fire and rescue as appropriate.

As for departing traffic on the ground - aircraft on their gate will be instructed to stay there. Aircraft taxiing to the runway will either continue to the runway holding point or be turned around to a gate, if available - this depends on whether I expect the runway to be closed for a long time (say, more than 20 minutes). The same, more or less, applies to VFR traffic in the control zone intending to land. They can hold in the air if I expect to reopen the runway shortly, otherwise they might have to find an alternate; I will coordinate any diversions with approach.

Once I have a hold of my own traffic, I will call the operational supervisor and inform them of the situation. They will take care of stopping additional inbound traffic if required, and coordinating with adjacent units and sectors. I might also call approach again directly to let them know how the situation is developing.

It will be up to approach, in cooperation with the supervisor and based on the information I provide, to determine if aircraft on initial approach should be diverted, or if they can hold in the air awaiting a runway reopening. Each individual aircraft will require individual handling, to determine if, where and how they want to divert.

Once the runway is reopened (after fire and rescue have finished their work, the emergency airplane has been removed, runway inspection carried out and so on), I will coordinate with approach and the supervisor to start inbound traffic again (possibly with a reduced rate), and start getting my own departures rolling again.

As you can see, there are a lot of "if's" in the above. A lot of decisions have to be made, and the basis for making said decisions changes depending on the situation. There is no set checklist or rulebook for when something like this happens, because the required actions will vary. But that is what we get paid for after all - as an air traffic controller you have to be creative and flexible, especially when unusual situations occur.

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  • $\begingroup$ Hmm. Side question that comes to mind reading this, how often does another aircraft in the air become an emergency due to low fuel because whatever it was inteding to do gets shut down. Not sure if seperate question; thinking out loud, should go have a search for low fuel inna bit. $\endgroup$ – StarWeaver Feb 3 '17 at 16:14
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    $\begingroup$ @StarWeaver The flight crew must legally decide to divert before a fuel emergency is inevitable. So in theory, that should never happen. $\endgroup$ – expeditedescent Feb 3 '17 at 16:18
  • $\begingroup$ Your mention of VFR traffic makes me wonder - would you issue a blanket "All VFR flight following services terminated" radio call or would you (have to) specifically address each aircraft? $\endgroup$ – FreeMan Feb 3 '17 at 16:22
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    $\begingroup$ @FreeMan I would talk to every aircraft. If they are inbound to land, they are already provided with air traffic control service (ATC), not just "flight following" (or the international equivalent - flight information service). I can't just terminate ATC service for controlled VFR flights (and would have no reason to or interest in doing so). $\endgroup$ – expeditedescent Feb 3 '17 at 16:28
  • $\begingroup$ Ah, yes, that makes sense. FF/FIS wouldn't be impacted by a runway closure unless they were inbound to land. $\endgroup$ – FreeMan Feb 3 '17 at 18:21

The immediate priority is to ensure aircraft separation is maintained, and send out rescue vehicles to the problematic aircraft if needed. Therefore, ATC will:

  1. Issue a "go around" instruction to the next arrival aircraft.
  2. Ask the pilots of the problematic aircraft if they need any assistance.

If rescue vehicles are dispatched, all ground traffic will be stopped. The controller may issue an "all stop" instruction to all aircraft and ground vehicles on the frequency.

Next, the controller needs to assess the situation. How long will it likely take? Is it a steering problem, or is the aircraft burning? If a prolonged delay is expected, ATC will:

  1. Contact the "approach" controller to stop sending aircraft to this airport/to the affected runway.
  2. If the airport has general aviation traffic, ATC may instruct the pilots to keep going around the pattern.
  3. Keep aircraft out of the airport airspace to reduce the controllers' workload.
  4. Notify the "ground" controller/dispatchers to delay pushing back aircraft.
  5. Give taxi instructions to aircraft prepared for takeoff so they can return to the gate.
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  • $\begingroup$ Actually, tower will coordinate with approach immediately, not only after evaluting the situation. The missed approaches must be coordinate, and a runway closure of any length must be coordinated - doesn't matter if it's 1 minute or 1 hour. $\endgroup$ – expeditedescent Feb 3 '17 at 14:03

Depending on how long the runway is expected to be closed (from a few minutes to clear it of FOD to more than a few hours because the aircraft wreckage is still on the runway) the tower will either put the incoming aircraft in holding patterns until the issue is resolved or be diverted to other runways which may require going around and lining up again.

Each aircraft will get its own instructions. There are at least 2-4 minutes between landing aircraft for separation/turbulence reasons so there is plenty of time to handle them one by one.

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    $\begingroup$ Where does "5 minutes between landing aircraft" come from? $\endgroup$ – Wayne Conrad Feb 3 '17 at 12:29
  • $\begingroup$ @WayneConrad misremembered data, actual numbers in aviation.stackexchange.com/a/26184/609 are a bit shorter $\endgroup$ – ratchet freak Feb 3 '17 at 12:37
  • $\begingroup$ @ratchetfreak Those only apply in case of wake turbulence concerns. A medium following a medium or a heavy following a heavy can be less. A quick search suggested 60 seconds separation for departures on a given runway and 3 nm for arrivals (60-90 seconds, depending on approach speed.) It seems like I heard a while back that ATL might be down to 45 seconds between departures now, but I might be remembering that wrong. $\endgroup$ – reirab Feb 3 '17 at 17:47
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    $\begingroup$ @reirab 45 seconds between departures sounds plausible when applying reduced runway separation standards $\endgroup$ – expeditedescent Feb 3 '17 at 20:58
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    $\begingroup$ @reirab: Or, presumably, a heavy following a medium. $\endgroup$ – Sean May 1 '18 at 17:22

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