Departure fires the starting gun on race to succeed chief
Michael Cawley's departure as joint deputy chief executive of Ryanair is the first sign that the founding generation of Ryanair managers won't be around forever.
As such, it raises wider questions around succession planning at the top of corporate Ireland's biggest success story of the past 20 years.
Indeed, the move almost certainly fires the starting gun on the race to succeed Michael O'Leary.
While the larger-than-life Mr O'Leary is very much the public face of Ryanair, no single individual, no matter how talented, can single-handedly create and manage a company that generated a turnover of almost €5bn and pre-tax profits of more than €600m in its last financial year. Working in the background at Ryanair have been some very talented executives, including Mr Cawley.
Whether and how the company can replicate that winning chemistry with a new generation of leaders will be watched not just by corporate Ireland but by the world's canniest stock investors.
So why is he quitting now? Although 52-year-old Mr O'Leary has frequently mused about the prospect of retiring in "a few years", he has never quite managed to do so.
With Mr Cawley hitting 59 this year, did the older man conclude that his chance of getting the top job had passed? Having recently successfully negotiated a 175-plane order with Boeing worth up to €11.6bn, he is certainly leaving on a high. Now that he has announced his intention of retiring as a Ryanair executive, one thing is certain. With his stellar business record, Mr Cawley will not be short of invitations to serve as a non-executive director on the boards of major companies.
Indeed, this has already happened. Ryanair has announced that he will be joining its board next May after he steps down from the day job.
A native of Cork city, Mr Cawley joined Ryanair in February 1997 as its chief financial and commercial officer in the run-up to the airline's stock market flotation later that year.
He was appointed deputy chief executive in 2003.
During his time with Ryanair, the number of passengers flown has risen from a mere 3.7 million in the year to March 1997 to 79.3 million in the year to March 2013.
Mr Cawley was already a battle-hardened senior executive when he joined Ryanair in 1997. Educated at Cork's Colaiste Chriost Ri, he graduated from UCC with a commerce degree before going on to qualify as a chartered accountant.
Before Ryanair, he spent four years as finance director of the Gowan Group, then one of the largest motor distributors in the country. Before that, he had been chief executive of plastics firm Athlone Extrusions, where he led a management buyout in 1990.