They're professionals in the cockpit Tony.
... although the majority of crashes are down to pilot error in one way or another. With ever increasing automation pilots often don't know what to do when something goes wrong and pressures on time/efficiency - keeping to schedules and avoiding penalties for the airline - have been proven to cause them to take shortcuts, occasionally with fatal consequences. One, perhaps relevant, that springs to mind is a couple of pilots trying to deice their wings by weaving across the exhaust of the plane taxiing in front of them to avoid going back to the stand and losing their slot, that plane dropped straight out of the sky after takeoff... food for thought.