uFly company owner Claudio Teixeira said he fired Mitchell Casado on Wednesday in part for his refusal to dress professionally and making Canadians "look very bad all over the world."
Casado's relaxed style of jeans and plaid shirts attracted attention during CNN's constant coverage of the search for the missing flight.
CNN's Martin Savidge and Casado logged many hours reporting from the fake cockpit located at the company's office in near the Toronto airport, which has a simulator that is the same model of the lost plane.
Teixeira said Casado didn't come to work Tuesday when customers had the simulator booked.
"This is not the first time. He's been warned before," he told The Associated Press.
Teixeira says he received many email complaints about the instructor's way of dressing during the time he appeared on CNN.
"Even though I let him be on TV he shamed us Canadians and shamed my company with the way he was dressing like he was 15 years old," he said. "People were complaining that it wasn't professional at all ... If you go to any plane you don't see them in shorts and sandals."
Casado declined to comment when reached by AP, saying "I'm not interested in talking to you."
In a tweet earlier, Casado wrote "My boss had me training a new guy the last few days, and now that he can do my job, and CNN left, he fired me. That's Ufly."
CNN spokeswoman Bridget Leininger noted Casado is an employee of uFLY, not CNN.
She said CNN will not broadcast from the simulator on Thursday but may do so in the future.
Savidge and Casado spent 12 to 18-hour days in the cockpit, using the machine to simulate what might happen under certain scenarios. They logged so much airtime reporting from the fake cockpit that the hashtag #freemartinsavidge appeared on Twitter.
Although CNN has been criticized for its blanket coverage, its viewership rose 84 per cent last month over what it had been before the plane went missing, the Nielsen company said.
When the cameras were off, Savidge took some informal flying lessons from Casado.
Teixeira called Casado a nice guy and wished him luck but said a change had to be made.
"I am the boss. I am the owner. I put in the money. It has to be my rules. If you don't agree with them you have to find another job," he said.
He said he gave Casado two-weeks pay.
Associated Press writers David Bauder and Frazier Moore in New York contributed to this story.
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