Is there too much pressure on airline pilots?
They are entrusted with our safety in the skies, but the case of the GermanWings crash has put the issue of pilots' mental health firmly in the spotlight.
The flight's co-pilot, Andreas Lubitz, had suffered from severe depression in the past and is accused of deliberately crashing the plane, killing all 150 people on board.
One pilot who was forced to give up his flying career says health problems are "just the tip of the iceberg".
Hugh Pym reports.