There's still no schedule for getting the grounded 737 Max back in the air, but Boeing's troubled airliner won a huge and unexpected lift on Tuesday when a major airline group promised to buy 200 737 Max 8s and 10s. International Airlines Group (IAG), a London-based holding company that includes British Airways, Aer Lingus, Iberia and the Spanish low-cost carriers Vueling and Level, signed the letter at the Paris Air Show, one of the most important events in the aviation world. 

"We are truly honored and humbled by the leadership at International Airlines Group for placing their trust and confidence in the 737 MAX and, ultimately, in the people of Boeing and our deep commitment to quality and safety above all else," Boeing Commercial Airplanes CEO Kevin McAllister, said in a statement.

Though the letter doesn't guarantee that IAG will eventually place Max orders, it's still a win for Boeing following two crashes in Indonesia and Ethiopia that killed 346 people. Prior to the crashes, the Max was the fastest selling airplane in the company's history. As of the end of May, Boeing still has 4,550 Max orders on its books.

With the grounding of the Max family now in its third month, the company flew into Paris with a pressing need to assure pilots and the public that the plane is safe. Investigators for both crashes have identified faulty sensors and a flight control system designed to push the nose down in the air as the likely causes. Boeing submitted a fix for the system to the FAA last month, but the agency hasn't said when it might complete its review.

Also in Paris, Boeing CEO Dennis Muilenburg said the company's public communication "was not consistent." During a separate press briefing McAllister apologized for "the loss of lives" from the crashes and the disruption to airlines caused by the grounded plans. Meanwhile, rival Airbus announced a new narrow-bod long-range airliner, the A321XLR.