Aircraft landings and takeoffs
The airport has two main east-west runways. At most times, one is being used for departures and the other for arrivals. (but see TEAM and ‘mixed mode’)
Aircraft perform best if they can land and take off into the wind. A good breeze gives them extra lift for take off enabling them to gain height more quickly thereby reducing noise further from the airport.
For about 75% of an average year, the wind blows from the West and Southwest. This explains why aircraft mainly land over Barnes, Kew, Richmond, and Sheen and then take-off the other way, over Windsor. However, when the wind is over 5 knots speed from the East, (for the other 25% of the year) the aircraft need to take off to the East. The aircraft noise then mainly affects Twickenham, Teddington, Whitton and Hampton. On days when the wind keeps changing direction, there is a time lag in changing the routes, due to the number of aircraft already lined up to land.
When there is less than 5 knots of wind or no wind at all, it makes no operational difference as to which way the aircraft take off. However, Air Traffic Control work to a rule known as “Westerly Preference”, which means that even though the wind can be up to 5 knots from the East, the aircraft still take off to the West. There is a debate as to whether or not this ‘preference’ should be maintained. Despite these rules, the final decision lies in the hands of Air Traffic Control.
Occasionally the speed or gusting of cross winds causes turbulence around the hangars and the runway has to be switched so as to allow the pilots to maintain control of their aircraft.
Departing aircraft should take off following one of several Noise Preferential Routes (NPR’S), which are designed to go over the areas of least population, such as Richmond and Bushy Parks. They should follow standard climb procedure to minimise noise, climbing steeply to 1500 feet and then at a set rate of climb. They are only allowed to leave the designated route when they are above 4000 feet, which is well outside our borough.
TEAM – Tactically enhanced arrival measures
TEAM is the procedure where aircraft are allowed to land to both runways, with the aircraft in a staggered formation (i.e. not directly side by side). This is done when severe inbound congestion occurs, or is expected to occur, involving airborne holding delays of 30 minutes or more, with at least 20 minutes delay in the inner stacks. As both runways are in use, there is no ‘alternation’
They already operate TEAM between 6-7 in the morning, and it seems they are using it increasingly during the day, in order to clear congestion in the holding stacks. This is a worry as it means that the whole place is getting too ‘busy’ and it means that there is no alternation for a period. One day they may get rid of alternation altogether and have ‘mixed mode’.
Mixed mode
“Mixed mode” involves both arrivals and departures to both runways simultaneously. The government have told us that if they develop proposals for “mixed mode” they will consult on it first. We are suspicious that they will want to bring it in, either instead of a 3rd runway at Heathrow, or more likely, as well as. We are well aware of the issues. “Mixed mode” would mean the end of “alternation”. We wholeheartedly support resident’s views that alternation is better. So we will be resisting the introduction of “mixed mode”, and will say so at any convenient opportunity. An additional point to oppose “mixed mode” is that the T5 Inspector fixed on 480,000 as the aircraft movement limit, so as to avoid “mixed mode”. He knew that the loss of alternation would be unacceptable and so tried to protect it. We also want to see it protected.