Three in four European airline pilots have taken microsleeps in the cockpit, while almost a quarter routinely fly despite being too fatigued to work, according to a report.

The findings, based on a survey of almost 7,200 captains and first officers by the European Cockpit Association (ECA), include pilots reporting insufficient rest, pressure to extend working hours and fears of being penalised for declaring themselves unfit to fly.

Almost a quarter (24%) of pilots admitted they usually continue flying rather than report themselves unfit due to fatigue, while another 16.8% said they call in sick instead.

In aviation, fatigue can result from long duty hours, insufficient rest, irregular schedules and flying across time zones, which disrupt the body's natural sleep cycle. It is a significant safety concern because it can impair pilots' judgment, slow their reactions, reduce alertness and impair responses to unexpected situations.

Under European aviation safety regulations, airlines are required to have systems in place to identify, monitor and manage crew fatigue.

The survey, conducted in August, found that three-quarters of respondents had experienced at least one microsleep – a brief, involuntary episode of sleep – while operating an aircraft in the previous four weeks.

Pilots working for airlines based in Ireland and Malta reported the highest levels of microsleeps. More than a third said they were not getting enough rest to prevent fatigue from building up over time.

Despite the prevalence of exhaustion, only one in three pilots said they usually reported themselves unfit for duty when fatigued. Half admitted they had operated a flight in the three months before the survey when they should have declared themselves too fatigued to fly.

Almost half of the respondents said they feared negative consequences from management if they reported themselves unfit because of fatigue, while just 11.9% trusted their airline's fatigue reporting system.

Ian Holder, the managing director of the aviation safety consultancy Baines Simmons, said the results showed persistent differences in how airlines and national authorities manage fatigue. "This survey captures how European pilots experience fatigue risk management in practice," he said.

He stressed that the findings represented pilots' first-hand experiences rather than a direct measurement of aviation safety outcomes, but said the consistency of the results over three years highlighted areas requiring attention.

Holder pointed to Finland and the Netherlands as evidence that stronger fatigue reporting cultures were achievable.

Pilots working for airlines based in Ireland and Malta were among the most likely to fear management reprisals and the least likely to trust the reporting systems.

The proportion of pilots who said they would fly when fatigued was higher in Spain, Ireland and France. Two in five of the pilots working for airlines based in Spain and a third of those working for Ireland- and France-based airlines said they usually fly when fatigued. That compares with only one in 10 of the pilots flying for an airline based in the UK.

Only 15.6% of pilots at low-cost carriers believed their airline managed fatigue risks well, compared with 18.6% at ACMI or wet-lease operators – companies that supply aircraft, crew, maintenance and insurance to other airlines.

Almost two in five pilots said they had used commander's discretion – allowing captains to extend crew working hours or reduce rest periods in exceptional circumstances – at least once in the month before the survey.

But nearly 70% expressed concern about refusing to extend their duty, suggesting that a measure intended for exceptional situations may be accompanied by significant pressure on flight crews.

Capt Tanja Harter, the president of the ECA, said airlines and regulators should take responsibility rather than leaving pilots to manage the risks themselves.

"This cannot be simply left to us – the pilots – to manage, while we are on the flight deck and expected to bring our passengers safely to their destination," she said.

She urged the European Union Aviation Safety Agency to strengthen fatigue management rules and ensure airlines comply with requirements for non-punitive reporting and the proper use of commander's discretion.

"Waiting for another three years to discover that nothing has changed is simply not an option," Harter said.

"The problems are identified, solutions are there, and we as the European pilot community are ready to contribute. What is needed now is the political will to act."