The United States Federal Aviation Administration (FAA) has rescinded the order halting commercial operation of the Boeing 737 Max.
The move will allow airlines that are under the jurisdiction of the regulator to take the steps necessary to resume service.
Boeing will also be able to begin making deliveries.
The aircraft type has been grounded since March last year after fatal crashes in Indonesia and Ethiopia killed 346 people.
Over the past 20 months, FAA employees have worked to identify and address the safety issues that played a role in the loss of Lion Air Flight 610 and Ethiopian Airlines Flight 302, a statement from the body said.
Throughout the process, the FAA said it has cooperated closely with foreign counterparts on every aspect of the return to service.
“We will never forget the lives lost in the two tragic accidents that led to the decision to suspend operations,” said David Calhoun, chief executive officer Boeing.
“These events and the lessons we have learned as a result have reshaped our company and further focused our attention on our core values of safety, quality and integrity.”
Throughout the past year and a half, Boeing has worked closely with airlines, providing them with detailed recommendations regarding long-term storage and ensuring their input was part of the effort to safely return the airplanes to service.
An airworthiness directive issued by the FAA spells out the requirements that must be met before United States-based carriers can resume service.
Changes include installing software enhancements, completing wire separation modifications, conducting pilot training and accomplishing thorough de-preservation activities that will ensure the airplanes are ready for service.
“The FAA’s directive is an important milestone,” said Stan Deal, president and chief executive officer of Boeing Commercial Airplanes.
“We will continue to work with regulators around the world and our customers to return the airplane back into service worldwide.”
Commenting on the news, Rob Morris, global head of consultancy Ascend by Cirium, said: “While there is no demand for the Boeing 737 Max in the context of fleet growth at present, once the aircraft is returned to service later this week there are a couple of drivers for demand for new aircraft which will ensure that Boeing are able to start deliveries again.
“The first point is that the aircraft will, of course, be around 15 per cent more fuel efficient than the 737-800s that it will be replacing.
“Even though fuel prices are low today and utilisation is also reduced over 2019 levels, that fuel saving could still account for something like $750-$1,000 per aircraft per day.
“For an operator like Southwest or United, that would soon multiply up to savings in excess of $1 million per month which in today’s environment where airlines want to preserve as much cash as possible is very welcome.”
Cirium data suggests there are currently 383 Boeing 737 Max planes waiting to return to service – though not all are based with US carriers and may thus have to wait for further regulatory approval.
There are also around 450 planes that have been built, but have not been delivered to airlines.
Morris added: “Airlines taking delivery of a new Boeing 737 Max will be able to offer the aircraft in the sale and leaseback market immediately.
“We have already seen appetite for Max sale and leaseback with several lessors and thus those airlines will be able to liberate the cash they have paid for the aircraft (deposit, PDP, final payments) and even potentially book an immediate profit on the sale.
“There are some airlines, Spicejet for example, whose business model depends upon sale and leaseback at delivery and such airlines, will be very pleased to see the Max back in service and deliveries available again.
“So while at face value there is limited demand for the Boeing 737 Max at present, once it is returned to service we expect to see a handful of new deliveries this year and then something like 360 or so next year, which would include around 200 of the pre-built aircraft.
“We expect these to effectively replace 737-800 on a one-for-one basis.”
Watch below as FAA administrator, Steve Dickson, discusses the final requirements for allowing the grounded 737 Max airliner to return to commercial service