LHR runway alternation query

[myrtleman]

Hi,
I was wondering if anyone can tell me the reasons for runway alternation at LHR whilst on westerlies not occurring.
I noticed on 15.2.06 alternation did not occur until two or three hours after the normal 1500 hrs switch over.
It's only very occasionally that this happens. What's the reason?
Thanks,
MM

[HEATHROW DIRECTOR]

There are a myriad of possible reasons...............

[SilentHandover]

Just as there are a myriad of reasons for a pompous useless reply to a genuine query!!!

Sorry I cannot answer your question Myrtleman , hopefully a more helpful Ppruner from Hounslow Municipal will be able to help you.

[shhhpotter]

Unfortunately as Heathrow Director says, there are literally thousands (myriads if you will) of reasons why the alternation was delayed. My guess would be to do with wind direction/strength. Currently there is/was a strong SSW wind, with the wind coming over the hangars it makes 27R final subject to windshear, severe turbulance in the last 1nm of the approach....this problem actually caused an incident with a Virgin not 3mths ago.
As 27L was the landing runway during the morning, I can only assume the strong wind may have been a factor for de-alternation.

[HEATHROW DIRECTOR]

Please let me apologise.. my comment was not meant to be pompous. Silenthandover has obviously never met me or he wouldn't make such a remark!

There are truly plenty of reasons for a non-alternation and the full stops after my posting were to hopefully lead to a posting from someone who might provide the answer.

Just for the record.. possibilities which spring to mind.. Strong SW wind can cause turbulence on one of the runways and this could delay the switch. Maybe there was important WIP in the undershoot? Maybe there was a crane in the undershoot? Maybe there was a lighting or ILS fault? Maybe there was some sort of special flight in the vicinity? Maybe a problem with some runway turn-offs? Maybe there was a broken light fitting reducing the length of the planned landing runway? Maybe.. maybe... C'mon guys; it's a 62-year old, long-retired brain dishing this out!

[Gonzo]

I believe today it was due to the strong SW'ly wind, which makes landing on 27R difficult with turbulence from the hangars.

[Airline Tycoon]

Gonzo,

Today we changed at 1500!

myrtleman,

Possible reasons:

Wind
Runway services (ILS or lighting)
Work in progress
Unavailable turnoffs
Obstructions (cranes in the T5 site)
Special flights inside the EGLL zone

[Gonzo]

Sorry, I meant yesterday! D'oh. :D

Well, now the day before yesterday....

I'll get me coat.....