On Monday, April 4, an Air France Boeing 777-300 operating flight AF11 from New York JFK to Paris Charles de Gaulle was approaching its destination and cleared to land when air traffic control picked up distressed voices coming from the aircraft's cockpit. Audibly alarmed, one of the pilots was calling for a thus-far unidentified someone or something to 'Stop! Stop! Stop it!'.

Climbed back up from about 1100 feet

As reported by the Aviation Herald, the disquieting transmission accompanied by chaotic background noises occurred when the aircraft was descending at approximately 1500 feet. The CDG air traffic control tower then instructed the crew to stop the approach. However, the aircraft kept descending another 300 feet, upon when the autopilot disconnect wailer sounded but not before the jet deviated to the left off the localizer. A go-around was initiated at about 1,150 feet.

The crew (whose priorities are in descending order to fly the plane, then navigate, and then communicate) became responsive again when the jet had ascended and leveled out at 4,000 feet. They informed air traffic control that the aircraft had not been following commands.

Due to the incident occurring towards the end of the flight, there was no need to dump fuel ahead of the landing, such as when a British Airways 777 performed an emergency landing at Heathrow in September 2020.

The pilots circled back, requesting to land on runway 27R instead of the initially designated 26L. This time, the approach transpired without incident, and the aircraft landed at 10:15 local time, five minutes ahead of scheduled arrival. As a bonus, it created a perfect paper clip flight path.

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The aircraft veered left during its first descent, upon which crew disconnected the autopilot and initiated a go-around, landing at a different runway. Photo: FlightRadar24.com

Aircraft involved remains on the ground

The aircraft involved in the incident is registered as F-GSQJ, a 17 years old Boeing 777-300ER that has been with Air France in different configurations since its assembly in 2005. In the days leading up to the go-around, it operated flights to New York, Miami, and Los Angeles.

At the time of writing, the jet remained on the ground. Simple Flying has sought a representative for Air France for comment but had yet to receive a response at the time of publication. This story will be updated when more information is available.

Meanwhile, France's Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) has rated the occurrence a serious incident and opened an investigation. The aircraft reportedly experienced a 'flight control instability', control stiffness, and trajectory oscillations.

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The aircraft in question was F-GSQJ, a Boeing 777-300ER delivered to Air France in 2005. Photo: 湯小沅 via Flickr 

As described by SKYbrary, aircraft trajectory oscillations are 'unexpected and unintended excursions in aircraft attitude and flight path'. Simplified, control stiffness refers to more force being required to perform an action than under ordinary circumstances. Meanwhile, according to an article in the In: Flight Physics journal from 2009,

The term stability characterizes the motion of an aeroplane when returning to its equilibrium position after it has been disturbed from it without the pilot taking action.

Have you ever been on a flight that had to interrupt an approach and initiate a go-around? What was the communication like from the flight deck? Did you ever learn the exact reason for the event? Leave a comment below and share your story with the community and us.

Source: The Aviation Herald, In: Flight Physics, SKYbrary