We have booked a holiday to Australia, flying into Sydney, and then to Cairns on the same day. Both of the flights are with Qantas, but we have to transfer from the international terminal to the domestic terminal, and there is only two hours between them. Is this too tight? Keith Dickinson, by email

Doc Holiday responds: Changing planes at an airport can cause great anxiety, particularly when the time between flights seems be less than generous.

Every airport has a set of Minimum Connecting Times (MCT) that indicates how long passengers will need to get from one flight to the next. They take into account security procedures, walking distances, inter terminal transport, and the time needed for luggage to be moved from one aircraft to another.

MCT’s vary from airport to airport. For example, the MCT in Vienna is just 30 minutes, whereas MCT’s in Madrid are up to 2 hours and 45 minutes.

The MCT isn’t something that a passenger normally comes across, but travel agents and internet booking must not book two flights under the MCT. If you are booked below the MCT for a particular airport, then the airline isn’t responsible if you should miss the onward flight. If booked outside the MCT though, it’s then the airline’s responsibility to assist you. If your first flight arrives late, then airline staff can escort you to the next flight, and in some cases even delay the departure of the outbound flight for you. And if you are so late that you miss the connection, they rebook you onto another flight at no extra cost.

You can relax with regards to your connection in Sydney though. The MCT there for an international flight connecting onto a domestic flight is 1 hour and 15 minutes, so you should have plenty of time to spare.

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