That's according to Ryanair CEO Michael O'Leary, on Friday.
He said Boeing originally told the Dublin-based airline they would receive 57 planes by the end of April.
However, just over a week ago the projection dropped to 50 by the end of June.
O'Leary says the number could drop even further, and that "If we only get 40, by the end of March we will have to announce some minor schedule cuts."
He was also sharply critical of the plane maker, repeating calls he has made before for Boeing management changes...
...and saying that Boeing has misled Ryanair about the severity of its crisis.
Boeing has been entangled in a regulatory audit and prohibited from increasing production of its 737 MAX planes since January...
That's when a panel blew out of a brand-new Alaska Airlines MAX 9 with it was mid-air.
In a statement to Reuters, Boeing confirmed that it has told some airlines that deliveries could be delayed as the company ensures planes meet all regulatory standards.
Ryanair's stock has risen by a quarter over the past two years, making it the best performing European airline in the post-pandemic travel boom.
But further capacity constraints could make the carrier less competitive against low-cost rivals like easyJet.
