BOEING CEO DAVID CALHOUN: "We remain proud of the product. We have the utmost faith in this product. And we could not be happier with the statement of support from Michael and the Ryanair team."

A ceremonial signing to mark another step in Boeing's road to recovery. CEO David Calhoun was on hand Thursday to mark the largest order for the 737 MAX since it was grounded for nearly two years due to two fatal plane crashes.

European budget airline Ryanair ordered 75 MAXs just two weeks after regulators gave the plane the okay to go back into service.

Ryanair CEO Michael O'Leary says the MAX, which he refers to as "The Game-changer" - already moving away from the tarnished MAX moniker - is now the safest plane in aviation history.

"I can not tell you how confident we are in the safety of this aircraft. Will our customers like this aircraft? They are going to love this aircraft. This has been a real partnership between Ryanair and Boeing . This is a great aircraft. We are proud to buy them. We're proud to fly them. And our passengers are going to enjoy flying on these."

The price tag wasn't disclosed but sources tell Reuters Boeing likely agreed to a discount of well over two-thirds of the $9 billion list price given the plane's recent troubled past.

The 737 MAX was grounded March 2019 after two separate fatal plane crashes - - one in Indonesia, the other in Ethiopia - - resulted in the deaths of 346 people. A problem with the plane's software was largely blamed for the accidents.

Boeing's CEO says that issue has been fixed and Thursday's news marks the culmination of a long, hard process to get regulators to deem the plane safe again.

"Our willingness to allow regulators to do anything and everything they want to do to this airplane. Give them the time. Be patient. Answer every question. Dot every 'I.' Cross every 'T.' And that's exactly what we've done."

Ryanair already had 135 of the MAX on order, so this additional order is seen as a pivotal moment in Boeing's efforts to rehabilitate the MAX, its fastest-selling jet at time when global travel is down due to the health crisis.

Earlier this week, there was a splashy flight for journalists ahead of the 737 MAX's December return on American Airlines.

Boeing is hoping for several more eye-catching deals to cement its comeback and spark a bounce-back in a stock that's lost a quarter of its value this year.