I've just been asking Google and here is its interpretation:
By granting the CLEUD for 941 movements, the council has officially ruled that these specific flights are immune from enforcement. Crucially, they have confirmed that these 941 movements do not count towards the 2,800 or 1,200 seasonal caps.
Before the CLEUD: 2,800 total summer movements (including the 941 quieter flights).
After the CLEUD: 2,800 seasonal movements PLUS the 941 "grandfathered" movements.
Where the 1,500 Figure Comes From
The "1,500" figure is the estimated total of newly available slots across the full calendar year once you combine the confirmed 941 baseline with other operational adjustments.
The 941 Base: This is the immediate "refund" of slots. Because these 941 movements no longer "eat into" the 2,800/1,200 quotas, the airport effectively gains 941 "fresh" slots within those existing quotas that it can now legally allocate to other flights.
The "Buffer" Maths: When you spread these 941 slots and combine them with the 10% "carry-over" rule (which allows unused flights from winter to be moved to summer), the airport's total operational ceiling for the year rises significantly.
Modern Fleet Efficiency: Because the council also confirmed that aircraft rated below 87 EPNdB (like the A321neo and B737-MAX) are the only ones that can use these slots, the 1,500 figure represents the total "growth headroom" for a modern-fleet airline to expand its base without hitting the legal buffers that caused the friction in 2022-2024.
What This Means for a New Base
For a carrier like easyJet, the problem with LBA has always been the risk of "quota exhaustion." No airline wants to base an aircraft worth £50m at an airport only to be told in August that they can't fly before 07:00 because the summer cap has been reached.
This decision eliminates that risk. By "banking" the 941 flights as a permanent baseline, LBA has effectively reset the clock on its seasonal quotas. It provides enough "unclogged" space for:
Jet2 to fully transition its new, quieter A321neo fleet into the night schedule.
Ryanair to increase its based aircraft from 3 to 5, utilizing the "freed up" space in the 2,800 cap.
A New Entrant to secure a consistent "first wave" of 06:00 departures, which was previously impossible because the quota was "full."
In short, the 941 figure isn't a limit—it's a legal shield. By moving those flights out of the quota, the airport has "unlocked" the remaining capacity for nearly 1,500 additional movements per year, providing the operational stability required for serious airline investment.