This latest report involved a flight last week on board the same plane involved in a similar incident Monday. A second American plane experienced the same issue Saturday.
American Airlines said they have identified the source of the problem: a seat clamp that was improperly installed on nearly half of its 757s.
Retired air traffic controller Bob Richards says in his 22 years in the O'Hare tower, he's never heard of such an incident.
"I haven't seen it, but then again there's a lot of things I haven't seen that have happened maybe once or twice and very freakish, so it's certainly not beyond possibility," said Richards.
At Foremost Travel in the Loop, clients are losing patience.
"We are absolutely not selling away from American Airlines. But the consumer, the perception from the consumer, is that there's a risk there," said Lynn Farrell, Foremost Travel.
It's a similar story at Ces Travel where bookings on American are down 40 percent.
"This airline has been a role model, like an ambassador to the whole world, and now its reputation is at stake. It's going downhill," said Anoop Walia, CES Travel.
American, which is in bankruptcy protection, insists the problems have nothing to do with contentious contract talks with its pilots.
"This is a mechanical issue. That's all it is. It's not related to anything else, despite all the rumors and speculation," said Bruce Hicks, American Airlines spokesman.
Since mid-September, American has been plagued by operational issues, which have delayed or canceled nearly half of its flights.
On Tuesday, a London-bound O'Hare flight had to make two stops; one for an ill passenger, another after smoke was reported in the cockpit.
"That's going to be big news today, and it wouldn't have been big news on another day if there wasn't all the other problems with American currently," said Farrell.
At O'Hare, Dallas passenger Jules Ryckebusch arrived late after the pilot reported a cabin intercom issue.
"It worked, and he called in a maintenance item anyway, and it delayed us 35 minutes," said Ryckebusch. "I think he's just pulling a card. I don't think anything was going on."
American and its pilots have not been at the bargaining table since August. On Wednesday, the pilots are expected to release the results of a strike authorization vote.