December was the busiest month for air travel in 2021 according to aviation analytics firm Cirium’s On-Time Performance Review 2021, with 2.43 million flights flown globally.

Nonetheless, the arrival of the Omicron variant late last year alongside operational challenges such as winter weather led to a surge of cancellations, with over 59,240 flights cancelled globally from December 24 to January 3 – the most flight cancellations seen in the month of December for the past decade. A total of 20,500 flight cancellations were seen in the first three days of the new year.

The US saw nearly 7,040 flights cancelled over this period by American Airlines, Delta, Southwest Airlines and United. These were driven by staff shortages across crew and ground operations.

Cirium stated that global flights flown increased 1.5 per cent week-over-week before the onset of Omicron from December 11-17, 2021, but that global flights were down 5 per cent the following week.

Jeremy Bowen, CEO at Cirium, commented:

“Flight disruptions affect airlines and airports differently – it depends on the availability and flexibility of equipment and resources in place to react quickly. Those that plan more conservatively will minimize their operational disruptions. Cirium monitors the level of disruption by measuring completion factor of flights and their on-time performance.”

The report also showed that American Airlines flew the most flights last year, at approximately 1,850,050. Hartsfield-Jackson Atlanta International Airport was the busiest global airport based on departing flights with 336,890 in 2021, while Amsterdam Airport was named the busiest airport for international flights in 2021, with a total of 123,070 departing flights.

See the full report here.

Meanwhile Heathrow has urged the UK government to scrap testing for fully vaccinated travellers after reporting that 60,000 passengers cancelled travel plans from the airport last month due to the impact of Omicron.

Heathrow urges government to remove testing for fully vaccinated travellers

Europe’s airlines are also expected to cancel many tens of thousands of flights in January and February, with the Lufthansa Group alone cancelling 33,000 flights in the coming weeks.