"Richard J." wrote in message
...
Cast_Iron wrote:

At present if an a/c taking off need to divert suddenly they simply
turn away from the other runway's flight path.

If you have three working in parallel where doe the middle one go?

The issue is not about a/c "needing to divert suddenly" but needing to go
around for another approach to land. If both the other runways have a/c
taking off at the time, I guess the middle a/c would fly straight ahead
until it was safe to turn under one of the other take-off paths. It makes
the circuit a bit longer, that's all. Presumably the problem has been
solved at Paris CDG and other multi-runway airports.

One of the three, at least, will be in use for take-off only. It ought to be
possible for the aircraft on the middle runway approach to turn towards that
other runway and do a circuit in that direction.

However at LHR the proposed third runway is a short one, and so presumably
will be used by smaller aircraft for both landings and take-off.
--
Terry Harper
http://www.terry.harper.btinternet.co.uk/