It has been a rough year for air travel. The most recent incident was the crash of Germanwings flight 9525. That case was unsettling for many. The plane crashed in the Alps after descending rapidly. There was no obvious mechanical culprit. After careful study of the flight recording devices and other information that was publicly disclosed, investigators revealed a conclusion that the press had already begun to suspect- the copilot was suffering from depression and committed suicide by crashing the plane.
Chilling aspects of the story haunted readers. For example, it became evident that the copilot had practiced the dive that would crash the plane, killing all aboard- he used flight simulators and repeatedly brought the simulated flight down below 100 feet of altitude. During the fatal flight, the copilot locked the pilot out of the cockpit to prevent him from interfering with the final dive. The details of this story, coupled with the suddenness of the crash, have led many to question whether pilots who have a history of mental illness, including depression, should be permitted to fly.
This is a valid line of inquiry. It seems reasonable to ask whether the crash of Flight 9525 was preventable and if it is possible to prevent similar catastrophes in the future. However, the truth is that making such a restriction will actually cause more problems than it solves.
First of all, consider the impact on pilots and potential pilots with depression. Instead of barring them from flying, all such a ban would do is encourage them to hide their history and symptoms. That is even worse than the alternative. If we truly believe that people with depression are a major threat on airplanes, then it is better to know who they are and know their day to day mental status than not know at all.
Next, it is not clear that this is anything but an isolated incident. There is no record of a modern pilot crashing his or her plane due to depression-induced suicide. Barring anyone with depression from the cockpit would be discriminatory without necessarily making it safer to fly. This was a spectacular incident, but there is no evidence that it is a real pattern rather than a one-off unlucky moment.
Furthermore, such a ban would be difficult to enforce. It would require that all pilots undergo regular mental evaluations, which would be expensive, time-consuming, and not necessarily effective at “catching” depressed people. Such mental exams can be gamed, so a determined person could slip through the web with some effort.
The bottom line is that making pilots with depression ineligible for flying would be a grave transgression of their rights without creating a safer atmosphere for flight. There is both no reason to have a general fear of pilots with depression and no reason to believe that banning them would make us safer.