Ryanair may only receive its first delivery of the grounded 737 MAX aircraft from Boeing in October, the airline's chief executive, Michael O'Leary, said in an interview with German magazine Wirtschaftswoche.
The 737 MAX, Boeing's fastest-selling aircraft, has not flown since last March following two crashes which claimed 346 lives. O'Leary told Reuters last month that Ryanair may not receive any MAX aircraft in time for its summer season.
One of the world's largest airlines, Ryanair has 135 of the planes on order, but none in service. O'Leary previously said it would not take orders in July or August because it is the airline's busiest time of the year.
"We were meant to have 58 planes by the summer," O'Leary said in the interview. "That went down to 30, then 20, then 10 and the latest is maybe only five. It's possible we'll only get the first jets in October 2020."
United Airlines has extended the grounding of its in-service MAX flights until June, the longest period that any US carrier has scheduled for keeping the aircraft out of service.
Boeing has been criticised by regulators, suppliers and airlines for providing what have turned out to be unrealistic estimates for the model returning to service and said last month that it was freezing 737 production in January.
In contrast to other airlines which have already agreed compensation with Boeing, including Turkish, Southwest Airlines and Germany's TUI, O'Leary said he that will only discuss recompense after the planes were delivered.