Flight routes

Aircraft landing over our Borough line up with the runway as far away as Greenwich using the ILS (Instrument Landing System). This is soon to be changed to the MLS (microwave landing system). By the time they reach Wandsworth, they are roughly at 3000 feet and then glide down on a 3 degree glide path to the runway (a descent of approximately 300ft per nautical mile). If this is done carefully using a low power/low drag approach (LP/LDA) and above 3000feet a continuous descent approach (CDA), it reduces the noise.

Heathrow are trying to encourage more and more airlines to adopt this procedure. In 2001 they reported that approximately 90% of all airlines were now using it on their approach to Heathrow. It has only slight benefit to Richmond residents as most aircraft are already on the glide slope when they are over the borough.

Runway alternation

This is a system employed by Air Traffic Control at Heathrow to share out the noise burden by preventing landing aircraft from using the same route all day long. For one week the Southern runway will be used for landings between 7am and 3pm, and the northern runway for take-offs. This pattern is reversed from 3pm – 11pm.

In December 1999 the DfT introduced a system of runway alternation at night (11pm – 6am) for both easterly and westerly operations. Please note that day-time alternation currently only applies to westerly operations, that is aircraft arriving over the borough from the east heading west.

The Cranford Agreement

Alternation does not currently apply to Easterly operations, i.e. when planes take off over our borough, over flying Twickenham, Teddington and Hampton so residents here can get noise all day, sometimes for weeks on end. This is as a result of the Cranford Agreement. Although not an official document, it was designed in the 1950’s to protect Cranford (situated close to the eastern end of the Northern runway), from excessive take-off noise.

Therefore, during easterly operations the northern runway and its final approach are used by the vast majority of arriving aircraft because the Cranford Agreement prevents it being used for departures, except in exceptional circumstances. Consequently the vast majority of departures over our Borough use the southern runway.

Whether or not this agreement should still stand has been the topic of much discussion in recent years. There would be winners and losers in our Borough if change were implemented. We experienced some of the possible effects during 2002 whilst the Southern runway was being repaired. This meant the southern runway was effectively closed at night time (10pm – 6am), Sunday night to Friday morning, and all landings and departures took place from the Northern runway.