Kjos, a former fighter pilot, said in a series of tweets he had tested the old system versus the new one in aMAX simulator.

More than 300 Boeing 737 MAX jets have been grounded worldwide after two fatal crashes in the past five months in Ethiopia and Indonesia killed nearly 350 people.

Boeing previously said on Monday it planned to submit a proposed software enhancement package for the MAX in coming weeks, after previously saying it planned to deliver the fix for government approval by last week.

Kjos said he had tested the old and the new MCAS software “under a malfunction”, saying the new system seemed foolproof.

“I hope the regulators will have safety in focus as always and not be directed by politics. I will gladly take my family on board a Norwegian MAX,” he added.

Norwegian has 18 Boeing 737 MAX aircraft in its fleet and dozens more on order.

The budget carrier has said it would seek compensation from the aircraft maker for the cost of leasing replacement planes while its own are grounded.

Meanwhile, investigators are expected to release a keenly awaited report today on the deadly crash of the Ethiopian Airlines jet, Ethiopia’s Transport Ministry said, giving the first official clues to the second crash of a new Boeing 737 MAX in five months.

Some 35 nationalities were among the 157 passengers and crew who died when the nearly full plane crashed six minutes after take-off from Addis Ababa, the Ethiopian capital, in clear conditions.

The March 10 disaster prompted a worldwide grounding of Boeing’s best-selling plane and scrutiny of its certification process.

“The 10:30am press conference is to present the preliminary report,” Ethiopian Transport Ministry spokesman Musie Yehyies said.

The report may shed light on how a piece of cockpit software came back to life after pilots initially switched it off as they tried to save the doomed jet, people familiar with the matter said, placing both technology and crew in the spotlight.