For noise Quota Count purposes, the Q400 sits in between early (PW124) and later (PW127) ATR-72s. The Dash-8 is exempted on departure (< 84 EPNdB, so zero noise quota used) but not on arrival, whereas newer ATRs are exempted on both arrival and departure and older ones on neither.
If only Flybe operated shiny new ATRs, they would automatically be top of the rankings.
