It is realistic, a fly-in to Perranporth airfield a few years ago there were 13 or 14 aircraft all within a couple of miles of the airfield whilst I joined the circuit, I could only see around 4 of them. Gliders (cloud huggers) particularly can be hard to spot. Sunlight glinting off hoods is often a good visual clue. Aircraft heading on an opposite bearing also can be tough to spot even when you have been warned by ATC services of their presence.

I do however believe pilots learn to spot them by developing a good scan. Passengers tend to not notice aircraft so easily.

It is realistic, a fly-in to Perranporth airfield a few years ago there were 13 or 14 aircraft all within a couple of miles of the airfield whilst I joined the circuit, I could only see around 4 of them. Gliders (cloud huggers) particularly can be hard to spot. Sunlight glinting off hoods is often a good visual clue. Aircraft heading on an opposite bearing also can be tough to spot even when you have been warned by ATC services of their presence.

I do however believe pilots learn to spot them by developing a good scan. Passengers tend to not notice aircraft so easily.