Colour Vision Defective Pilots Association

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Colour Vision in Aviation: Part 10

There are now two further appeals before the AAT in Melbourne by pilots with defective colour vision, and several more in hot pursuit.  It is symptomatic of the Department's "sacred cow" attitude to the colour perception standard that it is considering ways to have colour vision related disputes taken away from the jurisdiction of the Administrative Appeals Tribunal.  It is unlikely that any such a move could succeed, as it would involve the Parliament of Australia, where we have significant moral and political support for the "anti-colour vision campaign". 

As I have said time and again, the colour perception standard is an arbitrary discriminatory device used to exclude a minority of people from full participation in the aviation industry.  There is no logical basis for this standard, as I shall outline below.

The entire aviation licensing system relies on practical assessments of pilots by instructors and examiners of airmen.  That is, licences are granted at all levels on the basis that pilots demonstrate their ability to operate an aeroplane safely within well-established performance tolerances.  There is no doubt in my mind that people with defective colour vision are at no disadvantage in complying with and performing within those tolerances, day or night, private, commercial or senior commercial. 

The colour perception standard, on the other hand, is based on totally theoretical notions of the value and the use of colour in aviation, and is propped up with "scientific" evidence from "experts" whose knowledge of the aviation working environment is miniscule.  The standard itself is worded (see A.N.O. 47.3) in abstract and meaningless jargon that begs the question of what colours it is necessary to perceive to safely perform a pilot's duties.   Following my own AAT appeal and the favourable result, I am now doing a lot of night flying and demonstrating to a variety of "vision" and flying professionals (psychologists, ophthalmologists, avmed examiners, instructors) what little part colour plays in the pilot's visual tasks. A number of colour defective pilots have been with me on some of these exercises and, under the scrutiny of colour normal observers, have had no difficulty whatsoever in recognizing those things which need (i.e. are necessary) to be recognized.  This has been particularly so for the red-lit obstructions.  Several protans (red-defective) on these trips had none of the problems that the theoreticians have predicted with regard to red lights.  They were able to see obstructions at far beyond the limits of VFR visibility requirements.

My own night flying experience has convinced me of the point made by Dr McKelvey that many aerodrome lighting displays have been added "ad-hoc" with little explanation as to their significance or usefulness.  For instance, at Moorabbin Airport the lighting for runways 17/35 includes red light at both ends marking permanently displaced thresholds (which, by the way, I had no trouble seeing!).  If that part of the bitumen surface is not to be used, then why light it at all?  Secondly, for obstruction lighting to be usable, it must be accurately depicted on the relevant charts.  This, it turns out, is far from the case in the Geelong/Avalon area, and has been brought to the Department's attention by a colour defective pilot. 

I have been able to confirm, with colour normal observers on board, how little the navigation lights (once considered THE reason for the colour perception standard) do in fact contribute to collision avoidance and the safe separation of air traffic.  The enormous cost of an "experiment" performed some years ago to prove the contrary, could have been avoided by such simple practical observations, or even by just asking a sample of pilots. To suggest that pilots “probably DO use” the colour coded information in the navigation lights “subconsciously” is patently absurd. 

There is growing academic and political support for this campaign, as well as a significant degree of support from 

Departmental pilots such as the examiners of airmen.  It is also relevant that there is a growing realisation in other transport modalities that colour vision is a theoretical problem whose significance is not supported by the actual performance of people in real life conditions.  Thus, the Victorian Road Transport Authority recently removed all requirements for colour vision testing for all levels of driver’s licences.  Victoria was the last state to do so and in spite of contrary advice from the very same "expert” advisers that the Department (of Aviation) has chosen to rely on. 

The only extensive accident survey of colour defective pilots done anywhere in the world (the Dille and Booze studies) has shown conclusively that colour defectives do not have a significantly different accident rate per hundred thousand hours of flying time from the rest of the pilot population.  A United States Air Force survey, in which a number of colour defectives, who had somehow slipped through the net and become fighter pilots, found that these individuals had significantly better accident records than a closely matched group of colour normals.  Of all the colour defectives detected in that study, none was removed from active flying duties on account of his colour perception. 

In defence of our own Department, I must say that in the last twenty years they have given the colour vision problem a good deal of attention and that in some ways they have adopted a more liberal standard than for instance the U.K. and most of the European countries, some of which do not let colour defectives fly under any circumstances. I appreciate too that the officers of the Department have a most difficult task in setting standards that must take into account not only the pilots who fly, but the interests of the travelling and earth-bound public as well.  I don't envy them their job.

Also in defence of our Department, I should point out that the U.S.A. colour vision standard, although somewhat more liberal, is barely more rational than our own.  There the pilot is given an airborne colour vision test.  Leaving aside the control tower signal lamp, the pilot is asked to name the colours of particular lights that are pointed out by the examiner.  Clearly, if the light is on the threshold, the answer will be "green", at the stop bar "red", on the taxiway "green" and so on.  By the simple use of inverse logic, the colour can be deduced from the feature being pointed out, without the colour being actually perceived.  The relevance of control tower signal lights in the days before radio is unquestionable.  But it can hardly be considered relevant with the radio technology available today.  Our authorities rightly point out that such a "practical" test cannot be standardized and would not be acceptable to them. 

My argument is not that we should adopt the U.S.A. practice, but that it is not necessary to take an airborne colour vision test at all.  What is at issue is the ability to recognize those features, given the multitude of visual cues available to the pilot, that need to be recognized, such as obstructions, runways, taxiways and so on. The contribution of colour to these visual tasks is miniscule, a fact that can be and is easily demonstrated.  At the very heart of the colour vision debate lies one single important question:  What colours is it necessary to perceive for the safe performance of a pilot's duties? The answer is "NONE!" 

On the other hand, our Department can be criticised on this issue, for having sought advice from an extremely narrow source and for not having properly evaluated the "scientific" research that has cost taxpayers many thousands of dollars.  The research I refer to in particular are the "navigation light" and the "EFIS" experiments conducted by the Victorian College of Optometry, by non-pilots, on non-pilots and for non-pilots. It is the poor quality of this research and the un-critical acceptance and defence of it by the Department that has put them into an untenable position, from which it has become very difficult to retreat gracefully.  On the other hand Dr McKelvey's (a private consultant to the Department) research, also paid for by the Department and which found that colour contributed very little to operational decision making by experienced pilots, was attacked by the Department's witnesses at my own AAT hearing in a manner that showed that perhaps there was more than a little self-interest involved.  Dr McKelvey's research used real pilots (all from the Department), real aeroplanes and real visual scenes.  Clearly the results were unpalatable to a certain section of the Department that has tried to put this standard, at any cost, beyond question. 

No standard should ever be put beyond reasonable debate and argument.  It is a great pity that more individuals are going to be put to great expense, as will the Department, to argue before the AAT an issue that could easily and cheaply be resolved in real flight with real examiners in real aeroplanes on really dark nights.  I offer to take any Departmental official on a night flight to demonstrate the total irrelevance of this standard.

Also, and finally, it would not be unreasonable to suggest that aviation medical personnel should be required to hold pilot licenses so that they may better understand the workplace that they seek to regulate and that researchers commissioned to investigate such things as visual factors in aviation might be required to do the same.