Originally Posted by
LOWI
Many UK airports, especially in and around the London area (including LONDON... Luton).
They require CDA below a certain altitude.
Let's say 5000ft.
What conditions must be met for the CDA?
Minimum V/S? Is there a certain nm or time limit in level flight before busting the CDA?
Stupidly, does the CDA end at G/S capture or until touchdown?
From Heathrow's noise website...
METRIC: When an aircraft arrives, it shall not fly a segment of
level flight longer than 2.5nm below 6800ft.
COMMENTS: YTD 24hr CDA Average for 2025 is 89.90%.
Ends at touchdown.
I believe the 2.5nm leg maximum level flight is standard across the London airports, but different airports measure from different altitudes.