"The traditional Mk 1 Eyeball (a British RAF expression, I believe) seems to be mostly useless."
Don't agree.
My experience tells me it is certainly fallible, but I'm not going to start relying on anything else - especially more in-cockpit displays.
I hope no-one reading this thread is led to do that either. As humans we have a certain amount of 'attention' available - be careful what you spend it on . . .
My countermeasures have been to try and make myself as conspicuous as I can (fin tip and belly strobes, forward-facing LED 'landing light', frequent turns whilst en-route etc).
The RAF found that the best colour for conspicuity is black - not an option for me unfortunately in a glass-fibre-structured aircraft.
Anecdotally, most people (including me) say that when they do see aircraft, the other aircraft takes no avoiding action.
Consequently, there is a temptation to believe that our lookout skills are better than average, but you might want to ponder the following:
What would happen if, say, all pilots were exactly the same, and missed 90% of the traffic?
1% of the time, both pilots see each other.
9% of the time, pilot A sees pilot B.
9% of the time, pilot B sees pilot A.
81% of the time, neither pilot sees anything.
So what would they all report? When they saw traffic, 9 times out of 10 the other pilot took no avoiding action, and so was obviously not keeping a proper lookout like they were...
My experience tells me it is certainly fallible, but I'm not going to start relying on anything else - especially more in-cockpit displays.
Surely this statement is as erroneous as saying that you are not going to look out and JUST rely on cockpit displays.
"My experience tells me it is certainly fallible, but I'm not going to start relying on anything else - especially more in-cockpit displays.
Surely this statement is as erroneous as saying that you are not going to look out and JUST rely on cockpit displays."
To clarify: My experience tells me it [the Mk1 eyeball] is certainly fallible, but I'm not going to start relying on anything else - especially more in-cockpit displays.
My conviction is that manual look-out is very much better than focusing on more cockpit gadgets. It is also another reason to take someone flying with you.
On what basis do you justify your conviction?
I keep a lookout but accept that I'm not likely to see most of the nearby traffic. I don't worry about collisions overmuch, on the grounds that they're not the biggest risk out there to a private pilot, and at the moment it's not one that you can do a huge amount about. There are some decent psychology studies out there confirming what people with TCAS state - you don't see most of the traffic.
I used to work in the same department as a group studying insect vision. Locusts have just two dedicated see-and-avoid neurones, albeit rather complex ones, and I'd be willing to bet that within the next decade drones will use cameras to see-and-avoid better than we can. Perhaps we'll get to use whatever they end up using - the advantage being that you don't have to get everybody to agree on a common protocol for a collision avoidance system, which technically would otherwise be a relatively trivial exercise.
p.s. I've heard the thing about RAF jets being painted black because it was the most visible colour, but didn't manage to find any sources. Do you remember where you heard it?
"On what basis do you justify your conviction?"
All of my near misses (about 4 of them) were avoided when I was looking out. Worryingly, none of them were flagged/warned about by ATC. I also read in the GASIL reports that look-out is encouraged whilst looking-in is not - and given what GASIL do, I trust their view. I just think that more gadgets lull us into a false sense of security - especially in the case of TCAS, since not all a/c types carry transponders (gliders, kitplanes, microlights and baloons for instance). If you can afford it, fine, but spending attention time monitoring it instead of looking out, seems to me to be, folly.
Furthermore, I think that mid-air collision is actually the biggest single unrecoverable risk out there. Pilot error is consistently shown to be the main cause of accidents. Mechanical problems are typically responsible for less than 10% of them.
"Do you remember where you heard it?"
Search for 'RAF 4FTS Hawk colour' and there are a number of references to some trials done in the late 80's after a Tucano was painted dark blue and it surprised everyone that it was often the only a/c to be seen by the other pilots. The scheme for all training a/c changed to black soon after.
Thinking about it a bit more, it seems obvious that a dark underside against a bright sky and a light top colour against a dark background would both seem to be conspicuous. But what would seem to concern GA more is that margin between the ground and sky where our fellow aviators are wrt us. Profile is reduced compared with top-down or below-up views, and the background is often grey cloud - so is there a better colour? It certainly isn't white . . .
All of my near misses (about 4 of them) were avoided when I was looking out.
That's like saying "my spam filters work great because I don't lose any incoming emails" 
I can absolutely guarantee that you are not seeing at least 90% of traffic which passes within 2nm and +/- 1000ft of you.
Lookout obviously does work, in that our eyesight functions, otherwise we could not go about our daily lives. But it is clearly very poor for spotting light GA planes, against a background of fields, forests, etc.
Personally I always fly as high as CAS permits (and at "funny" levels such as 4300ft) so virtually all traffic indicated by TCAS is below me. That sets the usual background as "terrain" rather than "sky".
I think the sky is a much better background for spotting stuff, but for that to work you yourself need to be flying awfully low - probably exactly what the RAF do, and then a black aircraft will obviously be the most visible.
The exception to all this is when arriving or departing, when you are at about the same level as everybody else...
Incidentally, TCAS is quite good at spotting whose Mode C altitude is way off. On the ground, I can see a load of targets showing +00, and then I see one showing +03 whose transponder is reading 300ft high. I don't know if ATC quietly correct for that if you tell them your altimeter reading.
"I can absolutely guarantee that you are not seeing at least 90% of traffic which passes within 2nm and +/- 1000ft of you."
Other than your experience, are there any studies supporting this? I'm thinking about what proportion of that traffic passes through the 180 degree arc from your L to R and within plus and minus 500ft of your altitude. That was the region that my near misses occurred in . . .
"Lookout obviously does work" Yes - though it has limitations. It would be interesting to know if any prosecutions on the basis of poor airborne lookout have ever taken place. If we were talking marine law, the answer would be affirmative.
