A Spirit Airlines plane made a U-turn on a journey from Miami to Boston on Monday, after a passenger thought they spotted a fire.
Flight 3152 had taken off from Miami International Airport at around 6am, and was still climbing to altitude when a passenger called out “Fire!”
They had reportedly seen what they thought was smoke pouring from the vents above the cabin seating.
The crew made the decision to return to the departure airport in order to have the aircraft thoroughly checked out.
Police officers met the flight when it landed just 40 minutes after take-off.
The Airbus A321-20 was not found to have any fire or smoke aboard, with the airline later reporting that the substance the passenger had spotted was condensation coming out of the vents.
Spirit Airlines issued a statement saying: “There were no mechanical issues on board flight 3152 from MIA to BOS. A guest saw condensation from the air conditioning system and mistook it for smoke. The safety of our guests and team members is our top priority.
“The crew on board completed the necessary checklists to ensure there was no fire and returned to the airport out of an abundance of caution. Law enforcement and fire officials met and cleared the aircraft, which has since continued to Boston.”
The spokesperson said the flight had been able to take off nearly two hours late, at 7.45am, and complete its journey to Massachusetts.
Joe Kunzler of Simpleflying.com explained how the confusion could happen: “Aircraft air conditioning sources air from the big jet engines’ bleed air. This bleed air is then fed through a heat exchanger to a compressor turbine unit.
“The air is also hydrated passing through, thereby having condensation, which can be mistaken as smoke if and when that condensation passes through vents.”
Of the passenger’s decision to alert the crew, he added: “Ultimately, yelling fire in an aircraft is like saying gun in a shopping center – it’s gravely serious, so you better be sure you are correct that it’s a fire.
“The pilots and flight attendants have to presume the worst-case scenario and act accordingly. Nothing wrong with asking a flight attendant to confirm – they’re trained safety professionals.”
Plane diversions due to safety concerns are not uncommon.
Earlier this month a British Airways plane was forced to divert to Barcelona after a medical emergency was declared on board.
Meanwhile, on 4 November a Jet2 plane reportedly diverted to mainland Spain so passengers could use the toilets after services onboard stopped functioning.
