There are many different reasons as to why flights become delayed. However, the five most common reasons for flight problems are:
1) Bad weather
Weather is the most common cause for flight delays or cancellations. It can depend on the type of weather and how well the airport can cope in such situations. Thunderstorms and icy runways can stall flights for a few minutes or hours. Airports nowadays have de-icing equipment that can drastically speed up the waiting time. Whereas snow and hurricanes can be more unpredictable, causing much more disruption and often flight cancellations. If bad weather causes you to be heavily delayed then the airline will attempt to cite extraordinary circumstances although the level of weather disruption and the fact that it may be knock-on effect also need to be taken into account.
2) High traffic
Airports can experience traffic congestion especially in busy times with a high volume of flights. Air traffic control (ATC) handles all flight traffic ensuring safety amongst the different air spaces. Sometimes technical problems occur, or bottlenecks arise creating heavy delays. Air traffic controllers have a difficult job on their hands, as they must reroute aircrafts in cases of bad weather, security threats or if a high volume of planes are in the same airspace.
3) Mechanical issues
Mechanical issues are one of the most common causes for flight delays. Problems can arise from fuel leakages, electrical faults, faulty batteries or engine failure. The intricate mechanisms within an engine of an aircraft are so complex making it subject for errors. Airlines have to ensure that there are no problems before an aircraft can legally take off which is why stringent checks have to be carried out before each flight. If a problem is identified then repairs can take anywhere between a few minutes to several hours (passengers are often forced to wait on board until the problem is rectified). In extreme cases, passengers have to spend a night in a hotel whilst the repair work is organised.
4) Security threats
Security is a major issue in the air travel industry and passenger protection is priority. If there are any signs of a security threat either at the airport or on board an aircraft then extra precautions are executed, even if this causes a flight disruption. Strict regulations are already in place however if any suspicious activity occurs such as an unattended item of baggage then this could signal a high alert. Depending on the threat, flights may be grounded or in extreme cases diverted to a different airport, sometimes the flight is cancelled altogether. If a security threat occurs and causes you to be delayed, then again the airlines will cite this as an ‘extraordinary circumstance’.
5) Delayed crewmembers
If the crewmembers are delayed, it means that the flight will be delayed. For example, if a crewmember calls in sick one morning then the airline panics as they try to find a last minute replacement. Crew members can also be late due to being delayed on a previous flight (knock-on effect). For heavily delayed flights, the situation tends to worsen and crew delays are even more likely to occur. This is due to regulations that are in place that limit the amount of time that a crewmember can legally work. For example, a pilot working on a domestic flight can only work 8-hours before a period of rest is legally required. As this type of delay is within the airline’s control, you would be able to make a flight delay refunds claim for your loss of time (as long as you were delayed for at least 3 hours).