Boeing 737 MAX takes to skies for long-awaited test flight

US regulators conducted the first a test flight of the Boeing 737 MAX, a key step in recertifying the jet that has been grounded for more than a year following two fatal crashes.

A MAX aircraft took off from Boeing Field in Seattle at 1655 GMT, a Federal Aviation Administration spokesperson said.

The test lasted several hours, and included two take offs and landings, before finally touching down around 2115 GMT, according to an AFP photographer.

The initial flight will be followed by additional trips expected over about three days, the FAA spokesperson said in a statement.

But though the certifications flights are a critical phase, the regulator stressed that the process for returning the once top-selling aircraft to the skies is not over.

"While the certification flights are an important milestone, a number of key tasks remain," the FAA spokesperson said, adding that the agency will be "deliberate" and "thoroughly review Boeing's work" before allowing the plane to return to service.

"We will lift the grounding order only after we are satisfied that the aircraft meets certification standards."

The MAX has been grounded worldwide since March 13, 2019, following an Ethiopian Airlines crash that killed 157 people. | Ethiopian Federal policemen stand at the scene of the Ethiopian Airlines Flight ET 302 plane crash, near the town of Bishoftu, southeast of Addis Ababa, Ethiopia March 11, 2019.

That catastrophe came just a few months after a Lion Air MAX crash that killed 189 people. | Rescue team members stand beside body bags with the remains of passengers of Lion Air, flight JT610

The troubling similarities between the two accidents, both of which occurred shortly after takeoff, along with the pilots' inability to regain control of the plane, led global aviation authorities to ground the model indefinitely.

For months, the US aerospace giant has been struggling to get the medium-haul aircraft - previously Boeing's biggest source of commercial plane orders - back into service.

The MAX's anti-stall flight system, the MCAS, was partially to blame for both crashes. But other technical malfunctions, including one involving electrical wiring, were subsequently detected during the aircraft's modification process, slowing down its recertification.

Shares of Boeing opened sharply higher Monday and rose further following news the flight had taken off, closing at $194.49, up 14.4 percent, and leading the Dow.