The Irish Aviation Authority is investigating allegations that Ryanair pilots are being forced to work beyond legal flight-time limits.
In the past fortnight, a Ryanair pilot has issued a formal complaint against the airline, claiming he had been rostered to fly for longer than the 900-hour recommended limit for a year.
Several other complaints have been made to the British Airline Pilots' Association (BALPA), which expressed concern yesterday at apparent breaches in safety regulations.
A spokesman for the association said one of the complainants had alleged that more than half of Ryanair pilots were working over hours.
Ryanair has rejected the allegations, saying it operates to the approved flight-time limitation system, "whereby no Ryanair pilot may fly more than 900 hours in any year".
In a statement, the airline said: "Any Ryanair pilot who reaches 900 hours is not allowed to fly until the commencement of the following year."
An IAA spokeswoman said it was investigating the formal complaint as a priority.
"Any pilot who comes to us and says they are being asked to work 925 or 975 hours has the law on their side. It should not be happening."
However, she said, "to date we have not found evidence to back up the claims being made, and certainly not on the scale alleged."
The inquiry is concentrating on Ryanair's interpretation of an agreement with the IAA earlier this year to "zero" pilot hours on April 1st last. Ryanair requested the move to facilitate the introduction of new rostering procedures over an April-March timetable.
The IAA spokeswoman confirmed it had sanctioned the move. But, she said, "it was emphasised that, despite the permission, no pilot should go over the limit in any rolling 12-month period. It's the company's responsibility as well as the pilots' to abide by that."
In its statement, Ryanair defined its year as the period from April 1st to March 31st inclusive, a period which coincides with its "holiday year". It added: "Over the last year to 31st March 2002, no Ryanair pilot either reached or exceeded this 900 hour limit, and the average flight hours for each Ryanair pilot was 809 hours."
A spokeswoman for the airline was unable to say whether this meant no Ryanair pilot had reached or exceeded the limit over any rolling 12-month period.
The BALPA spokesman said, from its interpretation, "it would seem Ryanair is in breach of the regulations, and if so they should lose their licence to operate."
BALPA deputy general secretary Mr Graham Fowler added: "There is confusion, and confusion in the minds of pilots is an unsafe situation."
In its statement, Ryanair highlighted other aspects of its safety protocol, saying pilots "are also subject to individual monthly limits of 100 flight hours. This system is further enhanced by Ryanair's stable rosters, all of which are issued 28 days in advance, with a guaranteed minimum of five days off in every 14 day period, with pilots operating from their home bases and no night-time flying."
The airline pointed out that in Germany pilots are allowed to fly up to 1,000 hours each year. A similar limit applies in the United States.
In a separate development, the IAA dismissed suggestions made in the UK media that it operated to lower safety standards than its British counterpart, the Civil Aviation Authority.
"Both organisations are members of the European Joint Aviation Authorities, adopt the same requirements and are subject to the standardisation procedures of that body. IAA Regulations are not less stringent than those of CAA - they are effectively identical," the authority said in a statement.
