An aircraft's autopilot warns of possible dangers. But, says aviation expert Heinrich Grossbongardt, automatic intervention systems to prevent crashes do not exist - and for good reason.
DW: Initial analysis of the flight data recorders from Germanwings Flight 9525 has shown that the co-pilot made several changes to the airplane's autopilot settings, deliberately causing the final descent and accelerating the plane several times. Is it so easy to put an autopilot system on a crash course?
Heinrich Grossbongardt: An autopilot system does exactly what the pilots tell it to do. It doesn't automatically control a flight from start to finish; pilots enter certain settings, such a specific speed and altitude, and the autopilot maintains these settings. Nothing else.
Are there any warnings when a plane is on a collision course?
Every modern aircraft has an enhanced ground proximity warning system that alerts pilots when they fly too close to the ground. Such a warning likely activated in this case as well. In an emergency, it says "Terrain! Terrain! Pull up! Pull up!" or "Pull the nose up!" and pilots then follow through. Normally.
It's not possible to program automatic evasive action?
No. You have to see it like this: The pilots know the situation, and it can be the case that this is something they want to do, for whatever reason - to avoid some other danger, for example. And this is the pilots' decision - they know the situation and need to have things under control.
Notifications from the sensors are then only sent to the cockpit?
All warnings are only sent to the pilots. They are the ones who must act, and the only ones who can assess the situation.
Is it the same when an airplane risks colliding with another aircraft?
The autopilot doesn't intervene, even when there's a collision warning. Again, in such a case there's only a short auditory warning and a clear statement of what the pilots should do: evasive maneuvers, up or down.
So that means there are no instruments in place to prevent someone sitting in the cockpit from purposefully crashing an airplane?
If someone wants to purposefully crash a plane, as seems likely in the case of Germanwings, there is no backup. Nothing.
Heinrich Grossbongardt is an aviation expert with the Hamburg-based Expairtise Communications, an independent public relations and crisis communications firm focused on aviation.