The number of airline passenger complaints to the aviation sector watchdog last year more than doubled to 4,543 due to the Covid-19 pandemic.

The Commission for Aviation Regulation's annual report shows that the number of airline passenger complaints increased by 134% last year in "a record-breaking year" for its Air Passenger Rights team which was expanded to deal with the surge in complaints.

The report states that the Commission recovered €1.25m in refunds and compensation for air passengers - made up of €1.14m in refunds and a further €112,000 in compensation - concerning 2,039 concluded complaints following the Commission's intervention.

This compares to the 2019 total of €741,340 in refunds and compensation made up of €648,475 in compensation and €92,865 in refunds.

The report shows that Ryanair accounted for 48% of complaints with Aer Lingus accounting for 27% of complaints in 2020 while 84 other airlines accounted for the remaining 24% of complaints to CAR.

The number of complaints against Ryanair totalled 2,188 with 50% or 1,021 of concluded complaints to date upheld with 1,039 not sustained against the airline. A further 128 investigations are ongoing.

The report shows that 1,194 complaints were made against Aer Lingus with 50% or 524 of concluded complaints upheld and 516 not upheld.

The Commission has investigations ongoing in 154 complaints.

The report states that in total the Commission’s Air Passenger Rights team has completed the investigation of 3,947 complaints and found 1,908 complaints to be without merit.

It states that by January 29 2021, 2,039 of the 2,550 complaints requiring enforcement had been resolved with the airline in favour of the passenger.

The report also reveals that in relation to 3,491 complaints concerning flight cancellations, 1,804 were resolved through refunds or expenses with a further 1,179 cancellation complaints withdrawn.

Another 370 complaints were not sustained with compensation only paid out in 42 cases.

The report also reveals that in relation to 3,491 complaints concerning flight cancellations, 1,804 were resolved through refunds or expenses with a further 1,179 cancellation complaints withdrawn.

Another 370 complaints were not sustained with compensation only paid out in 42 cases.

The report states that due to the unusual travel conditions during 2020 "the majority of the complaints related to flight cancellations, as opposed to long delays as in previous years".

According to the report, 92% of complaints concerned flight cancellations.

"Due to the very high volume of cancellations air carriers were struggling to process refunds in a timely manner, and some airlines were failing to correctly advise passengers of their rights regarding refunds," the report stated.

The busiest months for complaints were April and May last during the first Covid-19 lockdown.

In her report, Commissioner Cathy Mannion said that the impact of Covid-19 on the aviation and travel industries "has been devastating".

Underscoring the impact on the travel industry, Ms Mannion stated that by the end of 2020, 181 tour operators and travel agents were licensed compared to 211 in 2019.

She stated that six related to insolvencies and following the insolvencies, the Commission received 3,620 claims from customers against the insolvency protection scheme.

The Commission report states that the largest proportion of the claims - 2,987 - related to the collapse of USIT Travel Ltd.

Last year, the Commission recorded a deficit of €117,00. The Commission's costs totalled €3.6m as its income amounted to €3.49m.