Ryanair could face legal action from the Civil Aviation Authority (CAA) for "persistently misleading passengers" about their rights over cancelled flights.

On Wednesday (27 September), in a letter addressed to the Irish carrier, the CAA warned Ryanair it faced "enforcement action" for failing to give customers accurate information after announcing almost 700,000 passengers would be affected by flight cancellations over the next six months.

In the letter, the aviation regulator argued Ryanair chief executive Michael O'Leary wrongly told passengers the airline did not have to organise replacement flights after the first round of cancellations was announced.

"There are clear laws in place, which are intended to assist passengers in the event of a cancellation," said CAA chief executive Andrew Haines.

"We have made this crystal clear to Ryanair, who are well aware of their legal obligations."

According to the regulator, the airline also failed to provide details about its obligations to refund expenses, such as meals and hotels, incurred by passengers as a result of cancellations. The CAA added that while its powers would allow it to fine Ryanair if warranted, it would not be able to issue further punishment, such as stripping the carriers of routes, as the airline is based in Ireland.

O'Leary has vowed to fully cooperate with the CAA but Haines warned his promises had to be taken with "a pinch of salt" as he urged the airline to get its act together, adding he was "furious" at the "disregard for consumers and for the law" displayed by Ryanair.

"They told us that last week and yesterday they continued to put out information that wasn't accurate and was misleading to people so I take that statement with a pinch of salt," Haines told Sky News on Thursday (28 September) morning.

"Let's see action not words."

More flights cancelled

Haines' strong words came a day after the Dublin-based airline announced it would cancel a further 18,000 flights between November and March. It added 34 routes will be affected by the temporary winter suspension, including London Stansted to Glasgow and Edinburgh, London Gatwick to Belfast, Newcastle to Faro, and Glasgow to Las Palmas.

The move will affect approximately 400,000 passengers and comes two weeks after a shortage of pilots forced the carrier to cancel between 40 to 50 flights a day until 31 October, affecting approximately 315,000 passengers across 2,000 flights.

The issue stemmed from Ryanair's decision to reschedule its holiday year to run from January to December, rather than the current system, when it runs from April to March. As a result, it had to allocate annual leave to pilots in September and October.

That, coupled with weather delays and air traffic control strikes, left the airline with no other option than to cancel 2% of its flights up until the end of next month and forced O'Leary to admit the airline had "messed up".

"We sincerely apologise to those customers who have been affected by last week's flight cancellations, or these sensible schedule changes announced today," said O'Leary.

"While over 99% of our 129 million customers will not have been affected by any cancellations or disruptions, we deeply regret any doubt we caused existing customers last week about Ryanair's reliability, or the risk of further cancellations."

Ryanair added it will fly 25 less aircraft from its 400-strong fleet between November and March and then fly 10 fewer aircraft from April 2018. That will translate to full-year traffic rising to 129m, instead of the expected 131m, which would nevertheless represent a 7.5% year-on-year increase.

By reducing its flying schedule, the Dublin-based carrier said it will eliminate all risk of further flight cancellations, because slower growth will create "lots of spare aircraft and crews" across Ryanair's 86 bases this winter.

Following the latest round of cancellations, the airline also expects to be able to roster all of the extra pilot leave necessary between October and December before introducing a new calendar leave from the beginning of next year.

"From today, there will be no more rostering related flight cancellations this winter or in summer 2018," O'Leary added.

"Slower growth this winter, will create lots of spare aircraft and crews which will allow us to manage the exceptional volumes of annual leave we committed to delivering in the nine months to December 2017."

Pilots association dismisses O'Leary claim

Meanwhile, as the fiasco escalates, the British Airline Pilots' Association (BALPA) has reacted angrily to O'Leary's claim that pilot fatigue as a result of flying in short-haul operations does not exist, and that pilots fly a maximum of 18 hours a week.

Brian Strutton, General Secretary of BALPA, said: "Fatigue is endemic in all kinds of commercial flying. To suggest that pilot fatigue in short-haul operations can only occur because of the pilot's activities outside of work is, in our view, wrong.

"BALPA is worried about what message this is giving to pilots, and what effect this management attitude has on safety culture."

Strutton said pilots are legally-bound to report their fatigue as it can have dangerous effects on performance. "Ryanair appears to be telling its pilots that if they report, their attitude will be that it's the pilot's own fault. This is not a good way to engender an open reporting culture. Additionally, the 18-hour figure that [Mr] O'Leary has come up with does not seem to have any basis in reality."

Pilots' flying and duty hours are rightly regulated in order to avoid fatigue. Current EU-level regulations limit pilots' duty hours to 60 per week, and flying hours to 100 in 28 days.

"If Ryanair cared to share their pilots' rosters with us we'd be happy to analyse them for fatigue. It is the responsibility of the Irish Aviation Authority (IAA) to regulate Ryanair. I think they should look carefully at these comments by Mr O'Leary and decide whether they could give rise to concerns about the safety culture in that airline," Strutton concluded.