Is this just Gatwick airport expansion by the backdoor?
No. These changes are intended to make the operation of Gatwick’s runway more efficient, reducing delay, fuel burn and emissions while managing noise more effectively for local communities. Runway usage for a single runway operation such as at Gatwick requires arrivals and departures to be interleaved – reducing the gap between departures provides no additional benefit to periods when successive departures are naturally split by the need to land an arrival in between.
Based on current demand profiles we would expect this to mean around 2-5 more departures per hour only during periods of high departure demand when the number of departures significantly exceeds arrivals – this is generally in the morning rush only and so does not represent a significant increase in overall traffic. Arrival rates are not altered by this airspace change as this is determined by existing separation minima and balanced by the demand of both arriving and departing traffic (an hour with less departure demand can see more arrivals handled on the single runway operation at Gatwick – as is the case today).
For more detail on the proposed changes at low altitudes around Gatwick see Part B.