The Boeing executive in charge of the company’s commercial airplane operation is leaving the company, The New York Times reports. Kevin McAllister had reportedly been at the center of Boeing efforts to fix the faulty automated system in the 737 Max airplanes that contributed to two fatal crashes in Indonesia and Ethiopia in the past year. The two crashes killed a total of 346 people. McAllister’s management of the commercial division and his handling of customer relationships have reportedly been under scrutiny at Boeing. Head of global services Stanley Deal will replace McAllister.

“We’re grateful to Kevin for his dedicated and tireless service to Boeing, its customers and its communities during a challenging time, and for his commitment to support this transition,” CEO Dennis Muilenburg said in a statement. The 737 Max planes have been grounded since March, costing the company at least $8 billion. This comes after Bloomberg reported that pilots discussed the faulty automated system in 2016, before the Federal Aviation Administration certified the 737 Max.