Understanding the data
The data is split into 11 sections for each day:
Arrivals and departures
The total number of arrivals and departures each day.
Wind direction
The percentage of easterly or westerly operations.
Early morning flights
The number of flights between 04:30-06:00. The Government place restrictions on the number of flights operating between 23:30-06:00.
Morning flights
The number of flights between 06:00-07:00.
Night shoulder flights
The number of flights between 23:00-23:30.
Night flights
The number of flights between 23:30-04:30. This is known as the night quota period. The Government place restrictions on the number of flights operating between 23:30-06:00.
Flight performance – 'On track' and Continuous Descent Approaches
'On–track' – proportion of departures that operated up to an altitude of 4,000ft within the departures route.
Continuous Descent Approaches – this involves aircraft maintaining a steady angle of approach when landing at the airport, as opposed to approaches which involve prolonged periods of level flight. CDA reduce noise because they require less engine thrust and keep the aircraft higher for longer.
TEAM & 09R Arrivals
Tactically Enhanced Arrivals Mode – the conditions under which TEAM can be used are 'when severe inbound congestion occurs, or is anticipated to occur, involving delays of 20 minutes or more'. TEAM rules state that we can land up to 6 aircraft an hour on the 'other' runway. The rules around TEAM are different between 06:00-0700. The rules state TEAM can be used between 06:00-07:00 where there is a forecast delay of 10 minutes or more in the 06:00-06:29 period, or 5 minutes forecast delay or more in the 06:30-07:00 period. TEAM began when runway alternation was introduced in the day in 1972.
The total number of TEAM arrivals on westerly operations – every flight that landed using TEAM including flights between 06:00-07:00.
The total number of TEAM arrivals after 07:00 – this is every flight that landed using TEAM (excluding flights between 06:00-07:00).
Total number of 09R arrivals on easterly operations – number of flights that landed on the southern runway on easterly operations.
Runway operations
Number of arrivals that operated on the designated departures runway – all arrivals that landed on the departures runway (or 'out of alternation') including the TEAM figures and those flights landing for other reasons such as emergency arrivals, or for maintenance/runway works.
Number of departures that operated on the designated arrivals runway – departures that took off from the runway that is being used for arrivals.
Departure vectors – the total number of departures that vectored off the departure route before 4,000ft because of the weather, such as thunderstorms or high winds.
Complaints
The total number of all complaints.
