LHR AM 24th: +RA, RVRs and LVPs
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LHR AM 24th: +RA, RVRs and LVPs
A question for our friends in the tower at LHR (and well done yesterday).
We arrived back at LHR yesterday ( 24th Sept) AM and ended up on the approach to 27 Left just as the weather deteriorated rapidly from the West. Tower were commendably quick in calling out the RVRs
. During the Flightdeck tapdance as to what we could or couldn't do, and who could do what with what we asked if LVPs were in force ( well, we felt we had to at least ask 
). The reply was, as I remember it: " No, they're not in force, the RVRs are not due to the visibility, they're due to the heavy rain"..
For my future reference, just how quickly can you get LVPs in Force at LHR and can anyone remember if LVPs have ever been in force anywhere purely due to rain?
We arrived back at LHR yesterday ( 24th Sept) AM and ended up on the approach to 27 Left just as the weather deteriorated rapidly from the West. Tower were commendably quick in calling out the RVRs
. During the Flightdeck tapdance as to what we could or couldn't do, and who could do what with what we asked if LVPs were in force ( well, we felt we had to at least ask ). The reply was, as I remember it: " No, they're not in force, the RVRs are not due to the visibility, they're due to the heavy rain"..For my future reference, just how quickly can you get LVPs in Force at LHR and can anyone remember if LVPs have ever been in force anywhere purely due to rain?
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I'm confused! What causes the low visibility is surely immaterial. Rain is just thick water droplets unlike fog which is thin ones. I suspect that the LVP's were not in force because it all happened a bit quickly and maybe unexpectedly (the drop in vis I mean).
I await a reply from a Heathrow Skygod for the definitive answer.
A I
I await a reply from a Heathrow Skygod for the definitive answer.
A I
Thread Starter
A I
Exactly - the LHR TAF yesterday AM certainly predicted the strong winds but the worse vis. was a TEMPO of 1500 metres in +RA so there was no reason for any thoughts of LVPs... until it all turned 'orrible just after we came off Lambourne.. Never mind, at least the roof of my house is still on
Exactly - the LHR TAF yesterday AM certainly predicted the strong winds but the worse vis. was a TEMPO of 1500 metres in +RA so there was no reason for any thoughts of LVPs... until it all turned 'orrible just after we came off Lambourne.. Never mind, at least the roof of my house is still on
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What were the RVRs? If not less than 600m then LVPs shouldn't have been in force.
If less than 600m, but safeguarding had not been completed (takes up to half an hour, maybe longer, during the day), then LVPs cannot be initiated as ILS protection cannot be guaranteed.
If less than 600m, but safeguarding had not been completed (takes up to half an hour, maybe longer, during the day), then LVPs cannot be initiated as ILS protection cannot be guaranteed.
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Gonzo
Didn't have time to write the RVR's down but as far I remember it:
Touchdown was 700 - 800 ish ( certainly above 550
)
Midpoint was around 300 -400..
Rollout was either Not available or not a lot...
As Geffen has said it came and went in a matter of minutes, our concern was the midpoint RVR migrating to the TDZ...fortunately it didn't.
As I said this was not in the Forecast or the Trend in the METAR for that matter so we didn't expect LVPs to be on tap - just wondered about the timescale - thanks for the replies.
Regards.
but as far I remember it:Touchdown was 700 - 800 ish ( certainly above 550
)Midpoint was around 300 -400..
Rollout was either Not available or not a lot...
As Geffen has said it came and went in a matter of minutes, our concern was the midpoint RVR migrating to the TDZ...fortunately it didn't.
As I said this was not in the Forecast or the Trend in the METAR for that matter so we didn't expect LVPs to be on tap - just wondered about the timescale - thanks for the replies.
Regards.
