LFB said the suspected fumes were in fact brake dust and there were no reports of injuries.
Air France confirmed that crews of flight AF1817 from Dublin airport to Paris-Charles de Gaulle decided to divert the plane “due to the detection of a smell of smoke in the cockpit”.
Passengers will be “re-routed” to Paris as soon as possible, the airline said, and the plane will be fixed before being returned to service.
Air France told the Standard: “The Air France crew, regularly trained to manage this type of situation, decided to apply the precautionary principle by requesting the presence of firefighters upon arrival.
“The aircraft landed normally at 7.58pm in London Heathrow. Customers have been taken care of at the airport and will be re-routed to Paris as soon as possible.
“Maintenance work will be carried out on the aircraft concerned before it is returned to service.
“Air France regrets the inconvenience caused by this situation and would like to remind that flight safety is its absolute priority.”
LFB said: “We were called to Heathrow Airport yesterday after a report of suspected fumes on board an aeroplane. Following investigation, crews determined the suspected fumes was brake dust.
“There were no reports of any injuries.”
The brigade was called at 6.51pm and the incident was over for firefighters by 7.24pm.
Heathrow airport confirmed the flight landed safely.