Something else about sights in CoD, ....

when I am for example flying the 109 and dogfighting with a Hurricane,
I do not loose it so quickly out of sight even if we turn and turn quite a bit, I still keep track of it. Of course harder against the ground than against the sky but still, I can follow it and eventually bring it down, if it does not bring me down first.

On the other hand, when I fly as the last bird in a formation and start leaving the formation just to fly behind it some barrelrolls or some other maneuvers, I loose the formation faster than the Hurricane in the dogfight, although, it should be easier to keep track of a steadyly moving big object like a formation of planes.

That happened of course also some times in the old IL2 but there you found your formation again very quickly, whereas in IL2-CoD you might need a few moments to find it again. If it takes too long, you have lost them for good.
:-)

As a (used to be) pilot in real life I think it is realistic.

I second that. Could use some optimization.
Here is how i handle it: Against the heaven and high distances i leave FOV at 50. Once i spotted someone i remain at 50 FOV since zooming in doesnt help at higher distances. The actual rendered 3D model of the plane at higher diestances is less visible than the "visibility-dots" you see when zoomed out. Only when you get closer to the target (say around 800m or so) it helps to zoom in since the plane then is bigger than the dots you see while in 50 FOV.
Against the ground i think zooming in is the only thing that helps at all. Spotting enemies above ground at higher than like 1500m is almost impossible.
Another tip: Spotting the enemies shadow on the ground is easier than spotting the plane itself. So once spotted look up and realize where the sun is. Being aware of that makes its easier to locate the enemy plane above ground.
Other than that i can only recommend to just practice practice practice. That helps the most.

Winger

is it realistic to have a bomber formation about 1k away, disappear as your staring at it?

They dont disappear at 1km. They just get that small that you loose them:)
I am certain that the distance at wich planes effectively dissapear is bigger than 1km depending on your resolution.

Winger

Yeah I noticed this too.

My experience in the game (so far) is they don't disappear, they just blend in with the ground (the reason for the camo paint schemes).

Try enemy view and I am sure they will be there. I will confess I have had to resort to this more than once )purely as an aid to my 64 year old eyes) for low flying a/c over land, especially around dawn and dusk.

The wonderfully made reflections on canopies don't help either, especially at dawn or dusk! Still, I love it ;)

Also find it hard. But I think its pretty realistic.
As someone else mentioned: in BoB pilots said they could one moment be in the thick of it - the next minute you were (ie thought you were) completely alone.

Also in RL its extremely hard to spot other AC:
Sometimes the easiest way is to spot a dot moving against the background.
Could be a white 737 - imagine this was a greenish spitfire: would be impossible to spot it.

But yes, its frustrating loosing sight of an enemy you know is there somewhere.
Been reading books about Dick Bong, Bruce Porter, George Barclay, Douglas Bader etc - and they rarely speak of 1on1 encounters. Guess its because its too hard to spot single AC, and also the usual operation was large groups in formations.

Funny to read how many times they had to return due to oil on the windshield...trying to find the way back...

But good to hear others having the same "problem" :) .

I remember from the Mig Alley sim that it was often the canopy reflections of enemy airplanes which would give you an early indication that there was something 'out there'. Apart from engine contrails at certain altitudes, of course.

Perhaps this could be modeled as well in a future CoD patch, that canopy reflections can be a bother, but may also help you spotting bogies (and vice versa)?