I am not asking if degradation is safe. Obviously it's less safe.
I am asking if removal of the colour green really makes any significant degradation at all.
You hit the nail on the head - degradation may be acceptable if other factors provide a compensatory element.
I believe that it makes such a tiny degradation that the affect on safety is negligible since there are so many other factors helping a pilot taxy at night like aircraft headlights and difference in texture between grass and pavement. I believe the reliance on colour is quite exaggerated - even your good self said you rely on the safety colour of the rotating beacon. I say it would not matter what colour was used.
I think that even a pilot with complete monochromacy 'vision like black and white Tv territory' would have no issue with avoiding rear-ending another aircraft on the taxiway. Do you really rely on the rotating beacon being red? If the red lens of the rotating beacon had fallen off could you mistake the taxying aircraft for something else and would you hit it? My own aircraft has a rotating red beacon and the lens is held on with a single bolt without a wire lock! Collision avoidance is not by recognition of colour it's by relative bearing - ask any pilot. Sure aviation uses lots of colours but in a very adhoc way.
Nobody really knows what another sees and many colour deficient pilots think they can see the colours. They are simply wrong. Any colour vision test shows that. Why do they think they can? Its because in the actual physical task of piloting they know they perform no differently than colour normal pilots. 99% of colour deficient pilots confuse white and green and have no problem recognizing red. I believe in modern aviation confusing white for green is not an issue.
Additionally there is simply no evidence that supports the idea that colour deficient pilots are unsafe.
Of course that's possibly because they have been eradicated to extinction in aviation by unjustly discriminative regulations. But not for pilots licensed in Australia where colour deficient pilots fly side by side with colour normals at all levels including international airline flying for the last 23 years. Yes! Colour deficient pilots fly 747s and A380s into Heathrow and elsewhere repeatedly and by day and night. Tell them they are unsafe!
More info at the Colour Vision Defective Pilots Association website (CVDPA)
Last edited by outofwhack; 11th Sep 2012 at 07:57.