A Spirit Airlines flight leaving Los Angeles International Airport returned yesterday, landing safely after fumes were reported in the cockpit and cabin. One person was taken to hospital to be assessed.NBC reported that the Denver-bound flight landed back in Los Angeles at 9.50am after fumes were reported.The Federal Aviation Administration (FAA) confirmed fumes were reported “in the cockpit and cabin.” Los Angeles Fire Department (LAFD) firefighters met the plane as it landed and according to NBC and Twitter, the LAFD has said oxygen masks were deployed.

The aircraft has been taken out of service for inspection

A Spirit Airlines spokesperson confirmed that the one person was taken to a local hospital adding:

“The aircraft in question has been taken out of service while our maintenance team inspects it. We apologize for the inconvenience, and we are currently working to accommodate our Guests on other flights.”

The FAA confirmed the incident via email to Fox News who went on to report that a Spirit Airlines spokesperson disputed that the oxygen masks were deployed.

Both the FAA and LAFD are investigating the incident, but according to Fox News have not identified the source of the fumes or odor. Fox News checked the plane’s flight number which showed it took off for Denver later in the day.

Fume and odor incidents occur

On April 24, another Spirit Airlines flight leaving Baltimore Washington International Marshall Airport (BWI) was forced to turn around and land. CBS Baltimore reported the issue was an “unknown odor” onboard the plane. The plane was turned around over Virginia about half an hour into the flight. A number of passengers at the time said they did not smell fumes. However, on landing seven people were taken to hospital. The seven included a flight attendant who was removed by stretcher. The affected were taken to Washington Medical Center.

A Spirit Airlines spokesperson confirmed the April 24 incident to Fox News at the time in a statement:

“Flight 301 with scheduled service Wednesday from Baltimore to Fort Lauderdale turned back shortly after takeoff due to an unknown odor presenting onboard. No Guests reported any medical issues. Our crew of 7 were checked out as a precaution.”

The affected Fort Lauderdale bound plane was also taken out of service and the incident investigated.

Spirit Airlines is not the only carrier to experience such incidents. On March 29, as reported by Fox News, a United Airlines flight from BWI to San Francisco was diverted to Washington Dulles International Airport. A strong odor was reported in the cabin and a number of passengers were taken to hospital for evaluation. United Airlines confirmed at the time:

“The aircraft landed safely and taxied to a gate. Customers were immediately deplaned and evaluated by medical personnel. Several customers were transported to local hospitals.”

One passenger, who also tweeted the issue, described a “faint fuel smell” which became stronger.

Simple Flying also reported on the United Airlines March incident finding that United had confirmed to passengers afterward that the aircraft required “ventilation system maintenance.”

The CAA records "fume events"

The cause of these recent Spirit Airlines and United Airlines fume and odor incidents has not been confirmed. However, toxins from aircraft engines can reportedly enter cabins through the "bleed air system." This is known as a “fume event” and the Civil Aviation Authority (CAA) requires airlines to report such events.

From an estimated one million flights that happen every year, the CAA records an average of 836 fume events. In a past public statement on the topic the CAA has said in regard to a European study:

“A recent study commissioned by the European Aviation Safety Agency (EASA), which maintains responsibility for approving the safety of aircraft and setting aviation standards for European airlines, concluded that the air quality on flights it tested was similar or better than that observed in normal indoor environments.”