Pilots need to undergo peroidic medical checks stipulated by CAA, however, the frequency of the check is contingent on class 1 or 2,how frequently you fly and the duration of the flight. The safety of the passengers rests with the Pilots. So a minor deficiency in the system or the Pilot error can cost many lives! But this seems to be an isolated case. Safety First Guys! By the way, I am not into the aviation field.