A United Airlines ExpressJet flight from New Jersey to Toronto had to make an emergency landing in Rochester, New York, just hours after a previous flight carrying the same passengers had to return to the Newark airport.
ExpressJet says Friday that Flight 4199 was near Rochester on Thursday when it was diverted to the western New York airport after the cockpit crew reported "a smoky odor" coming from a problem with the air conditioning.
The twin-engine Embraer 145 carrying 41 passengers and three crewmembers landed safely.
Atlanta-based ExpressJet, a regional affiliate of United, says the passengers had been on another Toronto-bound flight that had to return to the Newark airport because of a mechanical issue.
In Rochester, they were put on a third plane to complete the trip to Toronto.