Originally Posted by
A30yoyo
I'm just making the point that it was considered wise in 1948 to double the stack separation to 1000ft and now aircraft are up to 8x heavier (with stronger wakes), up to 2x larger (linear) and faster in the stack so is the separation still proportionate? Has it been reviewed in the light of airmiss statistics?
Airmisses involving aircraft in the hold are extremely rare.
ATC can monitor aircraft altitudes much more closely than they could in 1948.