So why did a Germanwings Airbus A320 fall out of the sky yesterday and what are the probable causes?
The aircraft flies on autopilot and follows the course inputted into the Flight Management Computer. These days the captain, despite having several thousand flying hours “on type”, does very little manual flying. Modern commercial aircraft are complex computers, monitored by trained pilots.
This does ask questions of a pilot’s ability to control an aircraft manually and some in the industry are looking into an area of increasing concern known as “automation addiction”. Planes are so safe and flying is so routine that pilots get very little hands-on experience. But there is nothing to suggest this in this case.
The Airbus is a brilliant but complex aircraft. Even starting it up and preparing it for flight requires significant training. The fly-by-wire system means the hydraulic flight control surfaces react to computer commands delivered by the pilot’s joystick or autopilot. The Germanwings A320 might have suffered a rapid depressurisation of the cabin, or the cockpit, or both.
This may have required the pilot to quickly fly down to a breathable altitude, 10,000ft, which over the Alps would have been unfortunate. The black box flight recorders will shed light on whether the aircraft may have skimmed the mountain tops.
Whilst modern aircraft can operate safely in bad weather, a dramatic thunderstorm might just be too uncomfortable for passengers. There is a small chance of airframe damage in a bad storm but it is unlikely. The plane was on a steady track at an altitude well above the weather. Investigators will look at the weather charts in those final moments.
Pilots would normally radio ahead if they wanted to change course or altitude due to bad weather. This was the case with the Indonesian AirAsia crash in December 2014. They were also flying an Airbus A320.
This was effectively ruled out very early on in this incident. Germanwings is a subsidiary of Lufthansa and no known terrorist organisation has taken issue with Germany in recent years. Since 9/11 airports are safer than ever, with multiple screening taking place of both passengers and cargo.
Cockpit doors are now closed and locked at the same time as the aircraft doors. Some airlines require cabin crew to guard the cockpit door when the pilot exits. No chances are taken and Germanwings has an excellent safety record in this regard. Smuggling an explosive device on board is relatively impossible in this region. Security is simply too tight.