Dozens of grounded Boeing 737 MAX aircraft are seen parked at Grant County International Airport in Moses Lake, Washington, US, November 17, 2020. (Photo: REUTERS/Lindsey Wasson)

US Federal Aviation Administration chief Steve Dickson signed an order lifting the longest jet grounding in commercial aviation history, and the agency released final details of the software, system and training upgrades Boeing and airlines must complete before carrying passengers. 

When flights resume, Boeing will be running a 24-hour war room to monitor all MAX flights for potential problems, from stuck landing gear to health emergencies, three people familiar with the matter said. 

The 737 MAX crashes in Indonesia and Ethiopia killed 346 people within five months in 2018 and 2019 and triggered a hailstorm of investigations, frayed US leadership in global aviation and cost Boeing some 20 billion USD. 

While US airlines can start flying commercially once they complete the FAA’s requirements, including a one-time simulator training session for all MAX pilots, flights elsewhere will depend on approval from other regulators across the globe.