Bealzebub

Having read through the many pages on this thread, it seems to be that a "practical" test would be more relevant ? Where such tests are undertaken it seems to involve lights being shone from control towers. I am not convinced such tests have any real world relevance at all these days.

Of more concern is the fact that all modern flight decks utilize CRT or LCD displays for primary flight instrumentation and navigation displays. The subtelty of colour interpretation is particularly important with these displays. In situations where a failure occurs to a colour gun or transmitter in such displays, the resulting hues can give problems to people with "normal" colour perception.

It may well be that new tests or existing lantern tests do allow for better colour vision test discrimination, however the importance of good colour perception should not be lightly dismissed from a safety point of view no matter what other countries may do, or however it may dissappoint.

Shunter

Bealzebub - noone is contesting the fact that you need good colour vision in order to safely fly an aircraft. There are numerous situations where it is neccessary to be able to reliably and accurately differenciate colours.

However good and perfect are 2 very different things. The vast, vast majority of people having CVD only have a mild problem. Severe CVD is extremely rare. Don't forget that people with perfect colour vision routinely fail lantern tests!!

I have to say that I don't think your faulty glass cockpit scenario holds water. "What Ifs" aren't really a very scientific way of addressing the issue.

belowradar

Bealzebub

however the importance of good colour perception should not be lightly dismissed from a safety point of view no matter what other countries may do, or however it may dissappoint.

lets actually start positively analysing and quantifying what the perceived actual safety problem is before we start devising tests to tell us what we already know.

Yes I am CVD but what is the related safety problem - nobody has actually proved any safety related risk at all (FACT).

No multiple crashes on our roads every night at traffic lights !! Lets get our heads out of the sand and take a more practical approach to this.

Not unreasonable to ask CAA to justify and prove the actual safety facts (unfortunately as they have not quantified the risk they can't and won't).

As for glass cockpits give me a break ! have flown G1000 and others and no problems FACT !!

colourblindgeek

Dear AMEandPPL
Please do not drop out of this thread. Your input is valued greatly. You have given some very valid arguements both ways. Yes, some have disagreed with some of your arguments, but the fact is that your input is from a different perspective than most on this thread, but your contrasting angle helps to balance the overall picture.

Please continue to support this thread with any input you feel is valuable.

Thank you.

Neo_RS14

Beazlebub,

The tower signal test is not the only possible practical test that could be employed here, if it was brain stormed a number of possible methods could be devised. This isn't rocket science. Although you think the tower signal test isn't really relevant anymore, it remains a part of current aviation, and therefore must be adhered to and understood. As a CVD I would rather be tested on a real world occurring tower signal light than a artificial laboratory constructed lantern light, and besides....why are there not reams and reams of safety incidents in FAA territory based on the long term use of this test, if the allegations that it is not sufficient are indeed true?????

I'll tell you why, because despite the test's simplicity, it is an effective means of assessing whether a person has enough coulour vision to safely perform the duties of an airman. If you read the thread in it's entirety, you'd learn that as a follow up test to the tower signal test, they'd have an 'in cockpit' test to verify the subject could recognise all the other lights used in aviation...they found after many years, that everyone who passed the tower signal test, passed the 'in cockpit' test...so it was abandoned.

The ability to discern the colours displayed by glass cockpit instrumentation is obviously critical. I've seen the weather radar and other graphical displays in an airliner, and have wondered why we aren't tested on something like this....why not have a real weather radar display, and some other controls in the AMC and test people on this? That I would happily label 'practical', as long as it was a genuine control, not a graphical reconstruction. Nice and easy, no need to take a trip down to an airfield, no need for a check ride/flight, and it relates to the real world.

Yes, I can imagine. You see an individual's own unique perception also is a major contributor to what colours they identify, hence the disputes that go on between colour normals over what colour something is...My father works in an environment where colour coding is critical, and he's told me of the numerous disputes over what colour something is or isn't between colour normals there.

As we should all be aware by now if contributing towards this thread, colour normals fail the lantern tests...not just by one or two fails which are deemed 'one offs', or 'freak'.....but 50% of a control group of colour normals failing the Beynes, and Anomaloscope.

It makes you wonder, if colour normals regularly fail the tests, what chance has a CVD person have You don't have to be Stephen Hawking to work out the chance is bloody slim!

Why would you think anyone contributing on this thread, or at least the regulars, would 'lightly dismiss' the safety issues of implementing a practical colour vision test? Clearly that is of paramount importance, and has been echoed in the majority of the posts on here. As I've said so many times, let us have a go at a practical test, and on failing that we would be content that we couldn't meet the standards requried by modern aviation, on the basis of the test material being directly related to the duties of an airman.

Otherwise, let me get my own group of seasoned full time commerical pilots holding current class one medicals together, and I'll start putting them through JAR colour vision tests, and Boy, you watch those failure figures rise.

See what you're saying by making people who fail the Ishihara test face the lanterns, is "this is the standard you must meet in order to be deemed colour safe", but it is my own contention, that if you made EVERY professional pilot candidate face the lanterns, many of them would fail.

So according to the tests done in the area, 50% of colour normals failed 2 of the CV tests, so you could argue that it is possible that around 50% of pilots receving their class one medicals are actually colour-unsafe!?!?!

2close

Hitting nail on head here.

The word 'Nepotism' springs to mind. Despite evidence which supports the Health & Safety Executive publishing a document which clearly states that CVD can develop with age the authorities still choose not to re-test individuals as they get older. Why? Can you imagine the major JAA carriers putting up with senior crew having their medicals pulled? The Old Boy net certainly protects its own and wouldn't allow that.

This goes hand in hand with the UK decision to permit 2 x flight crew members with Operational Multi-Pilot Limitations on their medicals to operate simultaneously on the flight deck of a multi-crew aircraft, quoting as the reason the statistical probability of multiple medical incapacitation. Yet those very same statistics don't apply to CVD (?) and they won't permit even one CVD person to operate on the multi-crew flight deck, despite a lack of any evidence to support any hazard to flight safety and statistical probability in favour of permitting such.

2close

Ditto, x lots.

Your input is valued highly and I did not mean to offend.

Only by discussing, possibly disagreeing and reaching compromise (or something similar) can we ever move forward on this.

It's also healthy that Bealzebub posts here with an argument against ours as this provides us a focal point for discussion. One sided arguments rarely move anywhere, let alone forward.

shgsaint

I've come across this site which has so far been quite interesting.

http://www.colblindor.com/rgb-anomal...lindness-test/

There was another Ishihara test of which I was fine with. However the point needs to be made that viewed through RGB an Ishihara plate is a lot different than through a printed CMYK plate.

The RGB anomaloscope test was interesting too. I'd advise people to have a look at it and see what their results are.

This was my result:
Thank you for taking the test.
Matching only a few values around the center means you are not colorblind or suffering just a very mild form of it.
The longer the line the stronger your color blindness is.

Thus with regards to this test i'm 'colour normal!'

Now if the CAA tested us through an RGB computer screen........I wonder how that would affect results???

An interesting website none the less.

Cheers.

SHG

Neo_RS14

Yes, this also puzzles me. It's fine for two pilots whom could potentially be incapacitated by an underlying health condition to form a flight crew, but an individual found to be "colour-unsafe" may not form part of a flight crew at all (with an OML), presumably as they are too risky (based on what evidence?) and like the 12 colour-normals in the study who are also "colour-unsafe" probably see red as green etc etc...

I could not agree more. Temperatures run a bit high on this thread at times, but that's only because of how passionate people are about this issue, which most of us have had to live much of our lives with. But without opposing viewpoints, we would really be going nowhere fast.

So please don't be put off by any heated comments, your views and opinions are valued highly.

Shgsaint

Thanks for posting that link, I took the anomaloscope test and at first thought like yourself I'd been classed as colour-normal....however, it depends on the line you get drawn on the graph at the end, as everyone gets the same message at the end of the test. I took the test and got a fairly horizontal line with a slight dip in the middle, a colour normal then took the test and got a tiny dot of a line.

I see the site owner promotes the use of the term colour-blind, I personally don't like the term at all. It couldn't be further from the truth for most of us...I imagine even the rarer dichromats have a fairly practical comprehension of colour for everyday life.

In fact, as a child I wondered what it would be like to be 'colour-blind', funny how I was actually colour-blind myself all along. Maybe that explains to a 'colour-normal' how what we see is actually probably not at all very dissimilar to what they see themselves. It's only during the tests where the difference can be noticed.

shgsaint

Ah sorry Neo if I wasn't too clear,

My result was exactly that of a colour normal..... the result was indeed a tiny dot of a line.

Strange.

PPRuNeUser0161

shgsaint
Took that test, it shows that I am red difficient, huge news! The thing about colorvision is that each CVD is an individual and sees his own set of colors. Testing color for the issue of an aviation medical is in my view a complete waste of time. It should only be done if the authority wishes to categorise the amount of pilots flying in the various categories for the purpose of gathering statistics.

I have flown all sorts of aircraft (18 years as an ATPL) including EFIS and I can tell you it has made not one bit of difference to me. Lets take for instance the WX Radar, very pretty all lit up like that, Black and Red = dont go there, Yellow = Caution and green = not as bad as yellow.

It does not display variations in hue. They are different and the CVD person knows the meaning of each as he sees them because he has seen the test mode and he has read the book.

Ther are hundreds if not thousands more like me. The CAA are saying if you dont pass at Ishihara then you must pass X lantern. That is so rediculous. Why not start with the lantern for everybody if its the bottom line? What a lowsy bunch of academics full of their own self importance, chances are they are frustrated pilots that didn't have the nuts to make it in this industry and want to get at those who do.

The fact is if a new benchmark for colour perception required for avaitaion is implemented they will never be able to re-test anyone who is currently flying unrestricted because the fact is they may fail the new test. Color defficiencies vary so infinetely that I dont think a test can be devised that will be consistantly failed by those who cannot read the tower lights and consistantly passed by those who can.

The only test with any relevance is the practical test for the perception of tower lights, even that could be made reduntant if they were prepared to think outside the square a little. EFIS systems are designed with color to look pretty and anyone who has flown one knows that all information is backed up by raw data. It has te be, if the sun gets on a screen it looks different, you still need the raw data.

Bealzebub

It is good that you all have seen EFIS displays and colour radars, but what you probably haven't seen is these same displays when a colour generator (gun) fails ? The difficulties that then be caused are quite profound. I have only seen this situation on rare occaissions so you could be wholly forgiven for having no personal experience.

On a distantly related theme, my wife who flies as a cabin crew trainer for another airline recently had a case where a steward was asked to bring an oxygen cylinder where a passenger had collapsed. He returned with a fire extingusher ! At the subsequent debrief it transpired that notwithstanding the obvious differences he admitted he was "colour blind" ?

I appreciate that bringing these comments and examples into this particular "lions den" is probably futile, but it serves to highlight the point that there are valid concerns that may eventually be overcome, but are not simply satisfied by the "FACT: FACT: FACT" merchants.

Neo_RS14

No worries at all shgsaint, I am the first one to admit that I am a bit quick to pounce (sticking with the lions metaphor) when discussing this subject, but I genuinely was taken aback by those remarks. But as said previously, only by things being said that not all agree with, do we ever stand a chance of moving things forward.

Yes Bezalebub, I can even recall cabin crew wannabes posting on this thread and enquiring about the CVD restrictions on them. I guess the situation you've highlighted is perhaps a reason for why they aren't so quick to employ CVD people.

But to be honest, the incident you've recalled for us in my own humble opinion, sounds more like an 'in the heat of the moment' error, where nerves are going, adrenaline is pumping, and the guy just grabs what he recognises as an oxygen cylinder, rather than properly looking at it at all, as the most obvious thing other than colour difference would of been the assembly for releasing the gas. I think he made this obvious mistake, and tried to cover his back by saying he is colour blind, thinking they will go easier on him, as it's a disability.

What colour are o2 tanks out of interest? I'm assuming the fire extinguishers are red

shgsaint

I sympathise with the poor lad.

Paint the thing bright yellow or yellowy green and it may be easier to distinguish. However if the O2 bottle is a dark green then I can see how the mistake could of been made. Especially in the rush and if the cabin lights were dimmed during a night flight.

During very dark environments I think it's is very hard to tell the difference between red and dark green....even to normal colour vision people.

I'm sure it was a very embarrassing moment for him.

belowradar

Bealzebub -
Join Date: Nov 1999
Posts: 690


It is good that you all have seen EFIS displays and colour radars, but what you probably haven't seen is these same displays when a colour generator (gun) fails ? The difficulties that then be caused are quite profound.

Your comments appear to be ever more strange ??

Forgive me but if a gun fails won't that screw things up for everyone CVD or not? again you just don't appear to get the fundamental points made by myself and many others which are as follows (pay attention now...)

There has been NO analysis of CVD that has proven any verifiable safety problem (CAA are too damn stupid and lazy to prove and verify what the actual safety problems are)

There are many CVD pilots flying commercially every day of the week without any problems.

I just wonder why you are on this thread and what you hope to achieve from your posts ??

Shunter

That's nothing to do with CVD, that's simply incompetence, brain fart, whatever.... Like the Mrs who just put the olive oil in the fridge because she reached mental overload cooking a rather complicated Thai curry. Do you seriously think that CVD prevents you from telling the difference between red and green? We may not see them exactly as you do, but we're still perfectly capable of telling the difference. Do you have a CVD problem? No? Well then frankly old bean you haven't got the faintest idea what you're talking about.

You might (and might is the appropriate word) stand a slightly better chance than us at telling the difference between a very, very, very, very light green and a very dirty white, but all this EFIS stuff is quite simply a load of bollocks.

Neo_RS14

Bealzebub, I can understand your concern...and I'm assuming I was correct in my assumption that red is the colour of aircraft fire extinguishers (in-line with other uniform designations)...if o2 tanks are green, well...I have to say, unless you have monochromatic vision (black n' white) mistaking bold green with bold red in whatever lighting conditions, is unheard of...it just hasn't happened...if it had, similar confusion would be occurring all the time, and obviously not just in aviationl...just think...8-12% of men have CVD....if it really was a major safety issue how often would we be hearing about the errors? At least a few times a year globally.

Thanks, I see you know where I'm coming from with my opinion on this. It's unfortunate that the cabin crew member involved resorted to such desperate measures rather than admitting that he made a simple but crucial mistake.

I can imagine what it must seem like to colour-normals, "Oh these colour blind chaps flying planes!?!?! Good heavens!"...It must seem so risky to you. You're not to blame, it's just poor education of what CVD actually involves which is the reason for such intolerant attitudes. The phrase "colour-blind" doesn't help, another antiquated thorn in the sides of all of us lot.

Colour blind....Seriously...it is EXTREMELY rare...personally, I have heard of one single case of it in my entire life. Yet, the majority of us CVD folk must be tainted with the same brush nonetheless. Again, no-ones' fault, but things can definitley be done to improve the situation.

Knowledge is power.

Bealzebub

My first post on this thread was over 2 years ago. Number 110 I think ? It became interesting when my son was certified as CVD during a class 2 medical (around post 206). He then had to have the lantern tests conducted at the CAA at Gatwick. He has just recently obtained his class 1.

I follow this thread out of interest, and occaissionaly take part to interject a viewpoint that may not always be welcome or appreciated, but is nevertheless valid as the de facto situation bears out. This is an open thread for discussion not a private meeting, or closed support group. My posts set out to achieve nothing other than to show an interest and offer alternative food for thought. What do you hope to achieve from your posts ? Beyond the same format for discussion, I doubt an internet forum will really achieve much.

TelBoy

As far as I am aware, all cabin crew need to pass the ishihara test so the crew member refered to would be colour normal - just like the pilots.

Neo_RS14

Indeed. But, still waiting for it!

Here's a thread on an optical forum describing the CAD test, it includes some quotes from Adrian Chorley.
UK Review of Electronic Colour Blindness Test - Contact Lenses Forum - Lens 101

...to develop a computer-based colour assessment and diagnosis (CAD) test that aims to be "fair and task-related", says CAA optometrist Adrian Chorley...

Task related? How's that then?

The most colour-critical task found so far concerns the precision approach path indicator (PAPI), which uses red and white lights to guide the pilot on the correct runway approach angle, but there are others, mainly outside the cockpit, he adds.

Exactly, so how come they abandoned the PAPI simulator that was also produce of the collaboration with City Uni? As I said earlier, I've met many CVD guys involved in aviation at some level, and none of them whatsoever had issues with the PAPI lights. If that is the most critical task, then surely the new test should eb based on this. And then maybe have some reference to other aviation lighting, such as runway, taxiway and parking bay lighting.

I have no confidence in the CAD test as a diagnostic tool at all unfortunately, as it uses averages to come to its conclusion. I myself took a version of the test at City Uni, and was utterly exhausted and found myself clicking the wrong button even though my eyes had seen the square change direction. The brain tries to automate basic motor movements to cut us some slack when we're fatigued, and I know I made loads of incorrect inputs during my test because of this.

I'm just so dissappointed that for a brief moment, everyone was onside. Both the authorities and the individuals were in agreeance that there needed to be a better fairer method of colour vision assessment....but then they started leaning towards some other academic crap, when clearly practical testing is efficient and SAFE the world over.