Iainhol From , joined Dec 1969, posts, RR: Reply 1, posted (13 years 2 months 2 weeks 6 days 22 hours ago) and read 969 times:
It is probably easier to get more take offs and landings if they use different runways. It also makes it easier as if a plane is slow taking off the plane landing behind it will not have to do a go around due to it. At LAX they use 25L for landing and 25R for take offs for the most part on the south side and on the north 24R is for landing and 24L for take off!
A student From , joined Dec 1969, posts, RR: Reply 2, posted (13 years 2 months 2 weeks 6 days 11 hours ago) and read 940 times:
Actually, all this is due to noise restrictions. The 09 runways are only used when the wind commands it, but the thing is that there are more settlements on one side than on the other, so it was agreed that if 09 runways are used, 09R will always be used for takeoffs.
For 27 departures, the current rotation system changes twice a day and once a week, I believe. (i.e. ay 1500 and some time in the evening, plus every monday the system changes, eg one week, 27L will be used for departures all mornings, next week it's used all afternoons)
By the way, it is estimated that Heathrow could actually increase its capacity by a few percent (1-3%, I believe) if they were allowed to use the runways for both purposes at the same time, and not use them in the rotation system that is in place now. That is caused by the fact that landings are more efficient than takeoffs, and therefore a bit of capacity is sacrificed. It's a shame about those noise restrictions and agreements with adjacent settlements, huh?
Kaitak From Ireland, joined Aug 1999, 12164 posts, RR: 35 Reply 3, posted (13 years 2 months 2 weeks 6 days 11 hours ago) and read 942 times:
Actually, this is something that came up as a thread on the PPRuNE site; there is an agreement with a village close to 09L, which prevents the use of this runway for departures. However, it is regularly used for landings.
09R is used for landings very early in the mornings; I was on a CX flight from HKG which used it. BA crews sometimes get to use it, for example when 09L is in use, it saves them the time and fuel involved in taxiing right around the aircraft and holding short of 09R to cross over to T4.