2 rwys north of the airport
OK, let’s have a go.
The existing rwys are about 2.5 mi. long and about 1.0 mi. apart. At present, Heathrow Airport Ltd. have 2 schemes for extra rwys.
South of the airport:
This rwy would take out Stanwell and Stanwellmoor and could be no further than 0.5 mi. south of 09R/27L because the King George and Staines reservoirs are in the way. It could also not cross the M25 because the Wraysbury reservoir is in the way. A rwy from Hithermoor Farm to the cargo area, for example, would be about 2 mi. long.
North of the airport:
This is the long-standing well-known “third rwy” scheme that would take out Sipson. This rwy would be about 1 mi. north of 09R/27L and would be about 1.4 mi. long.
Two rwys north of the airport:
There could be a 2.0 mi. rwy about 0.5 mi. north of 09R/27L, heading west on mostly open land from just south of Sipson to a point beyond the M25. This rwy would only take out relatively few houses (compared to south of the airport) and some other buildings around Hatch Lane, and possibly the relocation of Waterside. It would also require a diversion of the A4.
Let’s call it 10R/28L to be more accurate.
Another 0.5 mi. north of this of this could be the original “third rwy” scheme that takes out Sipson.
Let’s call it 10L/28R.
On westerly operations, this would allow landings on 27R and 28R and vice versa and take offs on 27L and 28L and vice versa.
On easterly operations, this would allow landings on 09L and 10L and vice versa and take offs on 09R and 28R and vice versa.
This could retain segregated mode and alternation.
It would allow two streams of aircraft either 1.0 mi. apart (this already happens in the 0430-0600 period on westerly operations when there are no takeoffs, and would happen all the time in the unlikely event of permanent mixed mode), or 1.5 mi. apart.
Why would this prevent simultaneous independent parallel approaches? Does this not happen at other airports?
As for aircraft taxiing accross rwys, this would be occur in both of Heathrow Airport Ltd.’s proposed rwy schemes. The extent would depend on whether new terminals and other infrastructure were built (likely), and their various locations.
With so much extra capacity provided by a 4-rwy airport, this should not be a problem.
Last edited by Fairdealfrank; 11th Jul 2013 at 22:14.