The random health checks on pilots is an effort to help reduce uncertainty over the pilots' mental health and reduce risks in the aviation sector.

Andreas Lubitz, co-pilot of a passenger jet of Lufthansa's fully-owned subsidiary Germanwings, is believed to have deliberately crashed the aircraft into the French Alps on March 24. He is thought to have a history of depression.
Lufthansa is weighing "unannounced health checks" of its pilots, which could be a possible way to help reduce uncertainty over the pilots' mental health, Spohr added.
In addition, the airline would examine very closely "under which conditions and in what exceptional circumstances doctors might have to be exempted from medical confidentiality obligations", he stated.
Source-Medindia