Peter wrote:
The safest way to fly VFR is at funny numbers like 3700ft and in solid IMC
And the transponder switched off 
Hmmm not what I had in mind 
IMHO from a purely collision avoidance POV random values are best, because traffic on a genuine collision course is a stationary point in your field of view, and flying semicircular levels ensures that a whole 180 degree worth of it will be doing exactly that.
“All is OK until it isnt”
Except that as has been pointed out, by restricting yourself to a specific FL as per “the rules”, you vastly increase the chance of being in the same piece of sky as someone else, at the same time, compared to choosing a random height…
One problem with cruising levels is that in reality, there are actually not much to choose because of transition altitude. So when theoretically I could choose fl35,55,75 , with TA for example in Estonia and Finland 5000ft the only options are 35 and 75..
ivark wrote:
One problem with cruising levels is that in reality, there are actually not much to choose because of transition altitude. So when theoretically I could choose fl35,55,75 , with TA for example in Estonia and Finland 5000ft the only options are 35 and 75..
The transition layer is really only applicable in controlled airspace. There is no prohibition about flying level in class G e.g. at 5500’ or FL55. Of course as a controlled flight, you won’t do that but then the semicircular rule is no longer applicable – you fly at whatever level you’re cleared to.
“So when theoretically I could choose fl35,55,75 , with TA for example in Estonia and Finland 5000ft the only options are 35 and 75..”
Aren’t you in controlled airspace then?
If everyone is flying at random altitudes in random directions you don’t think either Sod’s or Murphy’s law will play a part?
gallois wrote:
If everyone is flying at random altitudes in random directions you don’t think either Sod’s or Murphy’s law will play a part?
No. Quite the contrary. Murphy’s Law will play a part when everyone flies pre-established levels and pre-established routes.
The sky is big in principle, if you randomize it. What makes it small are humans and their obsession for “round” numbers and defined routes.
The same can be said of routing to radio aids (VORs, NDBs…) or to very prominent VRPs (visual reference points). Pilots go to these like flies to manure.
The vast majority of mid-airs happen in the airfield environment (circuits) because airfields act like “sinks”.
gallois wrote:
Aren’t you in controlled airspace then?
well, no- half of Estonia is G up to FL95 .Same for finland. Practically, we have 0 fliers without flightplan and higher than say 2-3000 ft – most A-B flights have to pass either tallinn or tartu TMA and usually dont’t shut down transponder (and are accessible on info frequency) in between. There are flights between smaller airfields without FP ,but in practice they are never higher than 3000ft. We also have glider areas – also near 100% with radios).
@Alpha_Floor whilst I agree with you about where most mid-airs occur, I don’t agree with your conclusions about flying the semi-circular rule at random Flight levels or random altitudes. I like to know where the threat is likely to be, random altitudes just adds further layers of sky to Vibal. It’s difficlut enough imo to spot aircraft even when told where they are.
We’ll have to agree to disagree :)
At least we can be certain that you and I won’t run into each other because you’ll be flying at a semicircular level and I will fly at a non-semicircular random level! :D
