Boeing Co began a series of long-delayed Boeing 737 MAX test flights, hoping to gain approval for the resumption of operation of the aircraft, suspended last year after two disasters.

Pilots of the Federal Aviation Administration (FAA) of the US and Boeing on Monday conducted their first test flight, which lasted about three hours.

'Boeing shares closed 14.4% higher at $194.49 on Monday', Reuters reported.

After completion of the test flights, the FAA should analyze the test data and approve new pilot training procedures, among other recommendations. The regulator is unlikely to approve the resumption of plane flights before September, industry and government sources said.

If Boeing receives permission, the company may resume flights of the 737 MAX in the US by the end of the year.

According to the regulator, a central task for the FAA is to validate Boeing’s upgrades to the MCAS anti-stall system faulted in both crashes, as well as perform a wide range of flight maneuvers and emergency procedures.

The agency said it will “lift the grounding order only after we are satisfied that the aircraft meets certification standards.”