What Happens When An Aircraft Diverts?

Many of us will have experienced aircraft diversions. These can happen for a variety of reasons, and although never desirable, they can be not too disrupting if planned well. This article takes a quick look at how airlines handle diversions and the different options available.

If the weather changes, flights can end up diverted, but there are plenty of other reasons too. Photo: Southwest Airlines

Diverting the aircraft

Neither airlines nor passengers want a diversion, of course, but they do happen. There are many different reasons why an aircraft may land somewhere other than its planned destination, including:

  • Weather. The most significant factor is the conditions at the destination airport. Although this is checked before departure, it can change during a long flight.
  • Technical issues with the aircraft. Any serious problems will cause the aircraft to land sooner. The severity of the problem will influence how soon this has to happen.
  • Medical issues. If the crew cannot handle any medical emergencies themselves, flights will often land to get medical attention.
  • Passenger disruption. If there is a threat to the aircraft, passengers, or crew, the flight will usually divert.
  • Safety or other concerns. Other unpredictable events can affect flight plans, such as airport closures, conflicts on the ground, or terrorism. The events of 9/11 were probably the best example of this when all aircraft in US airspace were ordered to divert and land.
Changing weather conditions can cause a diversion. Photo: Getty Images

Choice of diversion airport

Where an aircraft lands has a significant influence on handling the diversion. Airlines will try to plan diversions to airports where they have a presence, or at least where they can easily find and use services. Diversion points will be planned along the route based on this. If time allows, the crew may well continue flying to reach a more suitable airport, or even return to the departure airport.

For some emergencies, though, the aircraft will need to land as soon as possible. In this case, an aircraft can land at any suitable airport that can handle the size and weight of the aircraft, including military airports.

Landing at an unprepared airport can cause challenges, though. Aside from logistics of handling passenger disruption, there can be more fundamental problems like no available jetways or stairs for the aircraft, or a lack of customs and immigration facilities.

Anchorage Airport
Anchorage is a well-equipped diversion choice for routes between Asia and North America. Photo: Joseph via Wikimedia

Handling after landing

There are several different scenarios for handling a diversion, depending on the location, passenger numbers, and the severity of the situation.

  • In the most straightforward cases, the aircraft may continue to its destination after a short delay. This is common for temporary weather disruptions, medical issues, or even basic technical issues. Some passengers, of course, may miss connections and require re-routing. And there are costs to the airline in additional landing fees, disruption handling, and possibly compensation. Still, overall this will usually be a faster resolution.
  • Passengers may be switched to other flights. One of the advantages of landing at a major airport is that there are more options to re-route passengers to their final destination, either with the same or a different airline.
  • The airline arranges a replacement aircraft. Where no other flights are available, or passenger numbers warrant it, the airline may arrange another aircraft. At a hub airport, this could, of course, be taken from another flight. At an offline airport, an aircraft may be sent out, or even chartered to collect passengers.
  • For lengthier delays, passenger care or accommodation is arranged. If there is no immediate alternative, or a lengthy delay is expected while repairs are carried out, or a replacement aircraft arrives, airlines will usually arrange accommodation. Again, this is easier at an airport where the airline has operations or a scheme in place. At remoter locations, options can be limited, and the aircrew will be more involved in handling the situation.
Departure board Dulles
Landing at a well-served airport gives more options for re-routing passengers, but it can still be difficult to accommodate a full load of passengers. Photo: paul_houle via Wikimedia

Some recent diversions

For some idea of how diversions happen and are handled, take a look at some Simple Flying coverage of previous cases.

In August 2020, Hurricane Laura caused extensive delays and flight diversions across the southern US.

In February 2020, a Rossiya Boeing 777-300ER operating on behalf of Aeroflot diverted and returned to Moscow after flying 3.5 hours, with a cracked windscreen.

Air rage is a common cause of diversion. Such as this case of a United Airlines flight from Los Angeles, California, to Tokyo Narita, which had to divert to Anchorage after a drunken male passenger threatened to kill a flight attendant.

And for a slightly unbelievable diversion reason, take a look at this case of a British Airways Boeing 777 en route from London Gatwick to Florida. It diverted to Bermuda after a mobile phone became stuck in the mechanism of a business class seat, and started to smoke.

Would you like to share any experiences of diversions or handling by airlines? Let us know in the comments.