Ryanair has taken delivery of the first of 210 Boeing 737-8200s, formerly known as the 737-Max.
The Max version was grounded following two fatal accidents, but software changes mean it has been cleared to fly again and rebranded by Boeing.
The variant will allow Ryanair to carry 197 passengers, eight more than the existing version, but with 16% less fuel consumption and around 40% less noise and CO2 emissions.
Ryanair chief executive Michael O’Leary said: "We are delighted to take delivery of our first new technology gamechanger aircraft.
“Due to regrettable delivery delays, we expect to take delivery of just 12 of these aircraft during Summer 2021, with six delivering in Ryanair colours and six in Malta Air colours.”
Ryanair expects to take delivery of an additional 50 737-8200s before summer 2022.