EDI 21/12/17
 

Anyone know what happened at EDI about 14.00 this afternoon to cause all arrivals to circle over the town and environs (one RYR diverted to GLA) and no departures for about 45 mins?

Not suggesting any shock horror, just interested to know what no doubt pretty routine operational reason caused this. Thanks.

Localized fog!

Oh! I thought they all had zero viz autoland these days! Maybe need to get some BEA Tridents back! Or does EDI not have the required Cat III (or whatever) ILS then?

Cat III is no help when you're taxying and you can't see your nose in front of your face. :O

Pretty well any airport will see a drop in the movement rate when LVPs are in force.

Anyone have the appropriate TAF? (Forecast)..

For the OP - If it was down to unforseen fog then it is worth bearing in mind airports generally can’t just turn on Low Vis Ops (i.e. allow auto lands) instantly. There are measures that might have to taken on the ground before Low Vis Ops start, and then usually a need for increased spacing down the approach so as has been said the flow rate drops...and if you arrive just as this is kicking in you might have to look at other options....

That’s one reason why if there is a hint of fog in some airport’s morning forecast flow restrictions are enforced right from the start....then you sit waiting looking at blazing sunshine thinking...........

Some airlines/aircraft don't have autoland capabilities.

With the weather below you need Cat II or better.
ILS Cat I is good until 550 m Runway Visual Range (in the below table noted as R06/xxxx or R24/xxxx for the respective runways)

According to these jepp plates i found EGPH only has up to Cat II with a minimum RVR of 300m.
As you can see below it dropped below even that for a time, so no one could land.

Cat III requires quite an expensive amount of lighting for the runways and taxiways, especially if you want to go down below 300m RVR.


ARCHIVED METAR OF: 20171221 // FROM: 13 TO: 18 UTC
AIRPORTS REQUESTED: EGPH

EGPH 211320Z 30002KT 9999 6000N VCFG NSC 07/05 Q1032
EGPH 211350Z VRB02KT 9000 1500N VCFG NSC 07/05 Q1031
EGPH 211420Z 36002KT 0500 R06/0500 FG NSC 05/05 Q1031
EGPH 211450Z 33001KT 0500 R06/0600 FG NSC 04/04 Q1031
EGPH 211520Z 36002KT 2000 0500E R24/0400 PRFG NSC 04/03 Q1031
EGPH 211550Z 34003KT 0350 R24/0275 FG NSC 04/03 Q1031
EGPH 211620Z 32001KT 0400 R24/0325 FG NSC 03/03 Q1031
EGPH 211650Z 23003KT 0500 R24/0800 FG NSC 03/03 Q1031
EGPH 211720Z 24003KT 0500 R24/0600 BCFG NSC 02/02 Q1031
EGPH 211750Z 25002KT 0500 R24/0550 BCFG NSC 03/03 Q1032
EGPH 211820Z VRB03KT 0500 R06/1300 FG NSC 02/02 Q1032
EGPH 211850Z 24003KT 0400 R24/0350 FG VV/// 02/02 Q1032

We've got about 7/8 low clag here in Croydon, I just noticed that I can see the base and the top of one of the Crystal Palace transmitters - the middle is hidden... The other I can only see the base.

Not sure which plates you are looking at but they don’t tell the full story quite...There is at least one operator I know of, whose short haul aircraft frequently go in and out of Edinburgh, who has approval and appropriate “plates” (not jepp) for CAT3b Ops on 06/24, Nil DH, standard 75 m RVR TDZ/midpoint minima...

sorry i shouldn't have assumed. (random plates i found via google, don't have any jepp access)

still not all operators especially shorthaul with turboprops have CAT3 capability.

The EGPH AIP specifically refers to Cat III ops on both 06 and 24.

So to sum this up for the OP...

There are plenty of aircraft around these days capable of “doing a Trident”, and Edinburgh can support such operations....however setting up the ground side these operations can take time and if fog rolls in unexpectedly (which is why I wondered about the TAF/forecast) disruption/diversions can happen.....

So, guessing aside, Wonder if we will ever get the full picture from e.g. someone in ATC?

The only aircraft I saw land in 0 0 0 visibility was a foreign registered Trident many moons ago. Otherwise, nobody lands in zero vis.

I live in Edinburgh near the border and where i was it was clear as day. I could see 3 aircraft in a holding pattern at RWY 24 end roughly over the firth of forth. Strange thing though after 10-15 minutes of holding the aircraft’s got vectored towards RWY 06 to land and after a while inbound aircraft then proceeded to RWY 24. Why did it change briefly?

How did you see it ? :O

Sorry, couldn't resist !

I can't speak for this exact scenario, but it's very possible that the fog was thicker at one end of the runway (as often happens everywhere), so ATC switched to the opposite end to give better touchdown IRVR values. It's the touchdown readings which are much more important for crews. Sometimes it's not possible to do this (large number of outbounds taxying, or lack of ILS capability at one end, or significant noise restrictions for the airport etc), but if it's manageable, it can mean the difference between aircraft landing or diverting elsewhere.

Have fond memories of holding awaiting RVR improvement on 24 [ now 23 ] at GLA . Watch a patch of fog drift from threshold of 06 [05 ] towards the Clyde . Skipper calls in the improvement , RVR picks up for 06 , we position downwind for 06 , base , finals ... see the fog reverse direction and march down the runway to meet us . RVR down , Wave off , back upstairs to wait until it all melts/ burns off ; ignoring any further ' suckers gaps ' .
And yes it was a Trident . Fog forcasting is still an imprecise art , local knowledge very necessary . Temp / dewpoint closing , mixing breeze , lack of winter sun's heating , take lots of fuel .
Back then , 'tho no one else could do it . So no delays LHR - Scotland return twice , 4 @ low vis take offs , 4 @ 12' Radio DH , and 75m. RVR landings . All on Schedule , drive home very slowly and cautiously .

rgds condor .