Statistical Review of Flight Delay Causes: What Data Reveals About Airline Reliability?

Airline reliability is among the most important metrics, particularly measured by the statistical data on flight delays or cancellations. Cases, like denied boarding, flight cancellations, or long flights are regulated by The Air Passengers Rights Regulation 2004, which establishes compensation and assistance rules.

Airline reliability is a measure that shows how an airline activity, component, or system will fulfil its intended function without failing under certain circumstances over a specific timeframe. The flight disruption has economic, social, and operational impacts. It, in particular, lowers revenue for local businesses, hotels, restaurants, passengers lost value of time, and significant damages to the airline. The concept of airline reliability is divided into four parts:

1.Statistical reliability. It concerns collecting and analysing the data on maintenance events to create patterns and areas of improvement.

2.Historical reliability It relies on collecting and comparing the statistical data about flight delays and cancellations in the bast

3.Event-oriented reliability. It tracks the occurrence of one-time events that result in flight delays to investigate their cause for further prevention or reducing the chance of the same case.

4.Dispatch reliability. That is the percentage of flights that are performed without delays or cancellations. This measure marks the effectiveness of an aircraft maintenance program and serves as a performance indicator for most airlines.

Statistical data about flight delays

According to the Airlines for Europe, the largest EU airline association representing over 70% of all European air carriers, the number of flight delays has increased by more than 400% in recent years.

In 2022, the average delay per flight was 17.3 minutes, while this figure was only 9.2 minutes per flight in 2021. Such deterioration is mostly connected to the COVID-19 pandemic and the increased number of flights.

Additionally, the Ukraine-Russia war has become a significant factor in harming European aviation by limiting air space, thus making particular flight routes longer due to safety concerns.

The dynamics of delays and cancellations are also seasonal, taking into account the peak period in summer and the lower number of bookings in winter. In the meantime, extreme winter weather conditions like hazards and snowstorms can create operational disruptions, affecting flight schedules and punctuality.

The most common reasons for flight delays are:

1.Adverse weather conditions (15,5%).

Unfavourable weather conditions, such as fog, thunder, birds, tornadoes, and hurricanes, may impact the performance of the flight and thus become viable reasons for flight delays or cancellations.

2.Technical problems (5.8%).

Issues with engines, fuel contamination, and problems with water draining systems require quick reactions but, as a rule, are easy to fix.

3.Security and safety concerns (0,3%).

Before the engine even starts, the pilots, cabin crew, and ATC should perform a series of preparations and checkings to get security clearance. Some of these concerns include specifying the taxiway, considering weather conditions, fuel reserve, passenger load, etc.

4.Crew-related issues (2,6%).

Human factors can also make adjustments to the changes in flight schedules. If the crew is not in its entirety, which, for example, may happen because of traffic jams, the plane won't take off.

The impact of significant flight delays

According to Flight Compensation Regulation 261/2004, in case of a flight delay of over 3 hours, the airline is entitled to provide passengers with compensation from €250 up to €600. If the passenger chooses to rebook an alternative flight, the airline's duty of care includes vouchers for food and drink, accommodation, and transfer to accommodation.

However, the compensation does not apply to flight delays or cancellations caused by extraordinary circumstances considered out of airline control.

In 2010, the eruption of the Icelandic volcano caused significant schedule changes of around 100,000 flights in Europe. Ash clouds in the sky caused severe disruptions in aircraft operations. The financial damage caused by disruption is estimated at €148 million.

All in all, depending on the reasons for flight delays or cancellations, airports focus on optimising infrastructure and management, security procedures, and communication between airlines and airport operations. Optimising crew availability and the balance between duty and rest time also reduces the occurrence of delay issues.

How do flight delays define airline reliability?

Flight delays or cancellations affect passengers' future choices and shape the reputation of not only a specific airline but also the aviation industry. Furthermore, flight delays result in financial damages and operational disruptions. By mid-2023, the average delay for all European flights had increased to 15 minutes.

The European airlines with a significant number of delays are:


So, flight delays or cancellations may be an unexpected outcome for the passengers, and such breaking news may ruin their plans in the blink of an eye. However, there are some effective measures for continuous improvement in airline reliability and passenger experience. At Skycop, we examine your situation in detail to provide efficient and timely protection of the passengers' rights and a better experience. Stay tuned with Skycop analytics to be informed about the ever-changing dynamics of the air industry!