What happened to Flight BA919? Everything we know about plane 'stall' drama over London

A British Airways jet was reportedly "seconds from disaster" after a pilot blunder over London.Flight BA919 was flying from Dusseldorf, Germany, into London Heathrow on July 6 when it stalled near Canary Wharf, prompting a drop of 2,000ft in just four minutes, according to flight data. According to the Sun, the incident was caused by an air data system failure, which the first officer was unable to remedy, forcing the captain to intervene. The incident was declared a PAN PAN - the international radio signal for an urgent but not life-threatening emergency, before being upgraded to Mayday. A British Airways plane was forced to declare Mayday after a series of stall warningsAFP/GettyEverything we know about the incidentThe flight, which could carry up to 186 passengers, was flying from Dusseldorf in Germany into London Heathrow at around 11am on July 6. The Airbus A320-200 then suffered an air data system failure as it flew over Canary Wharf, triggering stall warnings on the approach to land and requiring intervention from the pilots on board. It is understood that the flight dropped from 6,000 ft (1,800m) to just under 4,000ft (1,200) in just four minutes. The groundspeed of the plane fell to around 148 knots, which is only slightly faster than the speed of a plane when it comes into land. The first officer was reportedly unable to remedy the serious situation, forcing the captain to take control. After the captain stepped in, the aircraft recovered to a height of 8,000ft and a speed of around 250 knots, equivalent to around 287mph. The incident has been reported as “loss of control in-flight” and described as “pilot induced”. ‘Mayday’The French Air Safety Investigation Authority (BEA) said: “During the approach phase, an ADR failure triggered a stall warning; the crew flew the aircraft under alternate law and declared a PAN”. Read MoreThe aircraft then suffered another stall warning at 3,000 feet, according to the BEA, accompanied by a potentially abrupt recovery manoeuvre. There were no fatalities caused by the major incidentGettyThe PAN status was then upgraded to Mayday, before the aircraft was safely landed without further incident. There were no fatalities caused by the incident and no damage to the aircraft. The statement on the BEA website was attributed to the UK’s Air Accidents Investigation Branch, but the UK investigators would not confirm it was from them. Flying under alternate law only happens when an aircraft has lost its automated safety net. It means that the aircraft stops preventing dangerous manoeuvres and allows the captain to take control of the flight’s safety. ‘The most serious near miss’ An unnamed source is quoted in The Sun as calling it “the most serious ‘near miss’ in the UK in years”.The source said: “To recover from this position is difficult, especially so low to the ground.“It is unheard of for a captain to physically intervene in the cockpit.”Other senior figures have described how the aircraft almost suffered a “hull loss” - meaning serious damage to or the destruction of an aircraft, as The Metro reported. The aviation publication Airlive has reported the official safety reports “point to a technical malfunction and a managed recovery under challenging conditions” as opposed to “an impending catastrophe.” The captain is understood to be grounded on “stress leave”, according to The Sun.InvestigationThe AAIB has issued the following statement: "The AAIB is investigating a serious incident involving a commercial aircraft which occurred on 6 July on approach to Heathrow airport."The investigation will be a correspondence investigation, meaning no team will be sent to carry out field investigations. Aviation safety investigator David Gleave told the BBC that there are different forms of Mayday calls and sending the emergency warning was “not unusual.” “You could have sick passengers on board who need urgent medical attention… so it's up to the captains' discretion as to what they call, but it's very unusual for it to be a significant failure on board the aeroplane."A spokesperson for British Airways told The Standard: “We're assisting the AAIB with its investigation and are legally unable to comment further at this stage.”