Michael O'Leary says Ryanair will let passengers with concerns about Boeing 737 MAX aircraft move to the next available flight on older planes.
The Ryanair group chief executive says he believes confidence will be restored in the aircraft "very quickly", but the airline will have no issue if people don't want to fly on MAX planes for the first couple of months.
The airline yesterday confirmed it is moving ahead with a plan to buy 210 Boeing 737 MAX airplanes.
The planes were grounded last year after 346 people died in two crashes in less than five months.
US regulators have given the green light for flights to resume after Boeing addressed software issues with the plane.
Ryanair is moving ahead with existing plans to buy 135 of the planes, but has now also confirmed its intention to buy 75 more.
Speaking on Breakfast Business, Mr O'Leary said the airline is confident the aircraft is safe.
He said: "If you look at the work Boeing has done, but also the safety regulators... a huge amount of work has been done to make these aircraft safe... and correct the fault.
"It is an important demonstration of our confidence in this aircraft, and an opportunity to begin to put COVID behind us and place a big order."
Mr O'Leary insisted confidence in the MAX will recover "very quickly".
However, he confirmed: "For the first couple of months, if people don't want to travel on the aircraft we have no issue - you can travel on the next available older aircraft.
"We think people will love the aircraft - the interiors are great, wider seats, more legroom."
Mr O'Leary point to the 787 lithium-ion battery issue - a high-profile aircraft problem which was overcome, allowing the plane to become a normal part of many fleets.
Collapse and recovery
Ryanair expects it will have flown around 35 million passengers this year - a "huge collapse" compared to 149 million last year.
Mr O'Leary said there's going to be a shortage of seats for summer 2021 and 2022, so the focus now is on recovering travel.
He said: "In Ireland for example, there's almost no flights at the moment in Dublin, Cork and Shannon. We've closed our Cork and Shannon bases this winter.
"They're definitely going to come back - the real challenge for the Irish Government is how fast they're going to come back. We're calling for them to roll out vaccines quickly in the first quarter of next month.
"We need an end to NPHET mismanagement of travel - and it has been mismanaged."
He also said the airline is calling for short-term discounts on airport fees for 2021 - suggesting the Government needs to play its role.
He insisted such cuts to fees would not go to Ryanair, and would instead be passed directly on to passengers.
Mr O'Leary also said it's too early to say whether he'll retire from the company when his current contract expires in 2024.
He said: "This industry is at its most fun when it's in crisis. When it's all going well... I think it's less interesting.
"Nobody would describe COVID as fun in any way shape or form... but good companies emerge and thrive through crisis.
"Let's fix 2021 first, and deal with 2024 when it comes around."