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lexxity
29th Mar 2005, 13:21
I don't know if any of you out there in pprune land can help, but I am curious as to what was going on at LHR this am that was causing such severe slots for I/B traffic.

Thanks in advance
lexxity

fly bhoy
29th Mar 2005, 13:27
lexxity

There was severe inbound delay due to us going in and out of low vis procedures.

Several go arounds as well due to the work in progress at A9W didn't help things!!!!:{

FB:ok:

lexxity
29th Mar 2005, 13:52
Thank you very much for that fly bhoy, I was just curious.:D

White Hart
29th Mar 2005, 15:08
A published arrivals rate of 29 per hour due to 'aerodrome capacity' may also have had something to do with it.:hmm:

GT3
29th Mar 2005, 15:14
And things werent much better on the ground either. The joy of LHR gave an Air Canada a total wait of 1hour 6minutes from landing until parking.

Its good here!

Jerricho
29th Mar 2005, 15:42
29 per hour due to 'aerodrome capacity' may also have had something to do with it.

Bring on mixed mode. That'll fix that :E :E

HEATHROW DIRECTOR
29th Mar 2005, 15:45
<<The joy of LHR gave an Air Canada a total wait of 1hour 6minutes from landing until parking.>>

Nothing new then - "remote holding" for departures used to hit 2 hours when I was there; must be a nightmare now!!

Gonzo
29th Mar 2005, 15:59
Get back in yer box, Jerricho!!!!!!!!!!!

point5
29th Mar 2005, 16:13
A good morning to be on leave! I could smell the LVPs in the air!
Get those blue skies back for next week...

Jerricho
29th Mar 2005, 16:24
Sorry :(

GT3
29th Mar 2005, 16:31
Point 5, in your absence we were allowed to increase flow. Hows the playboy mansion?? ;)

Ennie
29th Mar 2005, 21:36
Yep, lots of holding today, slots, and terrible weather. As ever though, an excellent ATC job!

missy
30th Mar 2005, 05:29
Can I please confirm that 29 per hour is your LVO arrival rate? If so, what is your normal rate?

Life as a journey
30th Mar 2005, 05:56
It was in 1997 that I visited Hounslow West, prior to LHS training in RBA's B767's.

Under the approval of the Shift Supervisor, a superb crew showed me around the Approach Radar pit for the London Terminal Area.

I also got to see runway operations from Heathrow's tower. Concorde taking off on 27L, at night, was worthwhile. After that it was downstairs to the dungeon (?) where the guys and girls work arrivals and departures for London City airport.

It was an outstanding day/night. If I remember correctly, the target for safety and service into Heathrow was 40 movements per hour; not sure about LVP targets though.

Thanks again to the team at Hounslow West, and to the Supervisor on the day.

Jerricho
30th Mar 2005, 13:49
If so, what is your normal rate?

Missy, are you asking about a flow rate or actual landing rate?

point5
30th Mar 2005, 16:21
GT3...

All fine thanx! The (mobile) playboy mansion hits the road on its European tour tomorrow. First stop... Dublin!

Shamoan mo fo!

missy
30th Mar 2005, 20:15
OK then, both really, flow and actual, LVO and normal, thanks.

Sean Dell
30th Mar 2005, 23:01
Just a quick question - why are LHR so quick to impose LVPs based seemingly around a 200' cloud base - surely we are still CAT 1 here and anyway isn't LVPs an RVR based phenomena? Or maybe this is another way of getting around staff shortages like when slot delays appear down route due to Adverse Weather at LHR, when the weather is fine. ;)

411A
31st Mar 2005, 02:18
Oh, I dunno SD, it would appear that LHR get their knickers in a twist at the very slightest problem.

Holding at LAM one day, the ATIS was reporting 4 km's yet there was a forty minute delay advised.
Seems they were going to LVP ops, yet nothing was mentioned to anyone on the approach frequency....only found about same while the F/E was listening in on the ground freq.

LHR really needs to get its act together.

In my experience, AMS/FRA works much better.:}

Evil J
31st Mar 2005, 05:55
Its been a while since i worked there so i stand to be corrected by someone still there BUT no one from an ATC point of view WANTS to LVP's, they are pretty much a nightmare wherever you work, particularly at LHR-and I would venture to suggest that going LVP's would exacerbate any staff shortage situation not help it, certainly from a tower point of view.

As for instigating them early, this is probably down to the fact that it takes so damn long to bring them into force at LHR. Yes 200 ft cloudbase is still inside CAT 1 minima, but it only has to fall slightly and CAT 111 protection will be required; if you wanted CAR 111 protection how would you feel if you were told it would take 45 mins to give it to you???

Not only that but until recently only one of the runways was CAT111 capable meaning that not only did the airfield have to be protected but an alternation had to be orgainised...not something that can be done at the drop of the hat....correct me if i'm wrong but AMS/FRA do not have such restictions and have more runways and concrete to play with??

Sean Dell
31st Mar 2005, 08:27
Maybe I am a little harsh - but just lately it seems to be happening a bit too often. For a 200' cloud base with forecast improvement in the weather- it seems a bit much? Believe me - if we see no improvement forecast we will be carrying the 45 mins extra ! I think the main gripe is not being able to see why LVPs have been enforced and why this hasn't fed its way back up the line to become a slot delay at point of departure rather than an unexpected airbourne delay at LHR. I think I will have to revise my way of thinking - a bit like treating PROB 30 SN as PROB 99 !

411 A - I think that FRA and AMS have their own little foibles too - ie. last minute changes of runway and (sometimes) poor appreciation of aircraft energy management - they are just luckier with their enhanced capacity.

Still damn fine controllers at LHR ! (and Swanick etc)

Mick Stability
31st Mar 2005, 09:25
Many people have mentioned about the closure of A9W, on the night before we autolanded and then rolled as fast as we could on a flooded 09L to try to make A8 ASAP. We started turning off at 30kts, and that’s as fast as we could safely achieve. Planning on anything west of that was unacceptable due to the runway state, and the fact that if you miss your turn, it’s a long way down to the next useable exit.

Even so the unfortunate chap behind us was sent around. That was particularly embarrassing:uhoh:, but we genuinely couldn’t do it any faster. With so many aircraft hurting for fuel, it seemed to us that about one in six were going around, which must’ve made for a lot of grey hair.

May I suggest that Heathrow gets A9W back in service as soon as possible? It can’t be as urgent as resurfacing taxiway Alpha round the north east corner with its gum wrenching potholes.:}

Gonzo
31st Mar 2005, 13:52
Mick,

Believe me, there's nothing we ATCOs would like more than to get A9W back in service. Next time I'm in work I'll try and get a ETA for that. However, as for the back massaging taxiways by T1, I reckon 2007 at the earliest!

WHBM
31st Mar 2005, 14:25
From a pax point of view it is increasingly unacceptable the extent to which short-haul services, particularly the domestic trunks, get significant cancellations (as on the day in question) whenever Heathrow gets into LVPs, which are surely to be expected quite regularly.

All that investment in Autoland over the years to enable operations to be maintained in poor weather is now wasted on these routes because when such conditions happen the airport has allowed such saturation of its runway capacity that the domestics end up getting cancelled anyway to meet the lower runway rates. And yet LHR higher management continue to peddle the public line that they are not at runway capacity yet.

DH1
31st Mar 2005, 15:43
missy - since noone's answered your question about a normal flow rate, under normal conditions / wake vortex mix LHR will average 41-42 landings per hour on one runway (the other being used for departures).

On a busy day there will be 680 arrivals scheduled between 0600-2259, or 40 per hour every hour for 17 hours. So, a flow rate of 29 for any significant period of time means that delays build very rapidly and airlines can do nothing but cancel. Cancellation rates can be 20% if the fog lasts all day (or if it snows).

Del Prado
1st Apr 2005, 14:51
Sean Dell, you asked whether LVPs were an RVR based phenomena. LVPs are applied when RVRs are 600m or less or cloud ceiling is less than 200'.
No matter what the forecast might be, if the met observations fall within these limits the procedures must be applied.

As for this not being fed back up the line to become a slot delay at point of departure, well it is. Obviously not as efficiently as you would like but weather forecasting is not an exact science (nor is flow control).

It would be very embarrasing for ATC to apply excessive flow controls only to see the fog/cloud lift earlier than expected, the landing rate increase and the stacks empty before delayed flights can leave their point of departure.

On the other hand, if ATC cancelled flow restrictions on the basis of a forecast weather improvement which did not materialise we'd be left with 30min EATs plus an over delivery of maybe 15-20 aircraft in the next hour (and nowhere to put them).




WHBM, you make a very good point but inevitably some days the capacity at Heathrow will be reduced.
This may be down to low visibility, snow, strong winds, aircraft emergencies or airfield unservicabilities. If these conditions reduce capacity by 20% some days would you propose the airport runs at 80% capacity every day to obviate domestic cancellations ?

WHBM
2nd Apr 2005, 14:54
Just interested to ask the experts what the anticipated flow rate would be if we had full simultaneous ops on the two runways (I presume someone must have calculated that) and what the LVP rate might be under those conditions too.

Even if we don't get simultaneous ops at all times possibly it's something that can be advocated when conditions are poor.

Jerricho
2nd Apr 2005, 15:01
Unfortunately WHBM (and I'm sure my buddy Gonzo can expand on this), the ground environment at Heathrow becomes very congested very quickly when you use 2 runways. Probably becomes counter productive.

Gonzo
2nd Apr 2005, 15:14
Occasionally, my friend Jerricho is correct!

Mixed mode would work for twenty minutes, and then you'd get the situation of nothing at the holding points because all the aircraft are in a massive traffic jam!

Lots of other reasons why mixed monde won't work, I'll list them all if you'd like! If you purely think of it in runway terms; presently we average 80-82 an hour. In mixed mode you'd be looking at something like 90-100.

I remain convinced that in mixed mode, our GMC capacity actually decreases.

halo
2nd Apr 2005, 15:24
Actually, you will find that those Low Vis criteria values you have given are incorrect.

Low Visibility Procedures are in force when:
1) The IRVR is LESS THAN 600m (Met Vis when IRVR is not available)

and/or

2) Cloud Ceiling is 200ft OR LESS

overstress
2nd Apr 2005, 22:47
Ah. LHR. That delightful S/H destination.
It can be CAVOK, 10kts down the strip and 40 mins holding. Why? Who knows.

Take 'company fuel' at your own peril.

A9W unavailable and a corporate Falcon 500 ahead wh has never been to LHR before ahead at night in filthy wx, my favourite. :{

Lost_luggage34
2nd Apr 2005, 23:26
OK explain to me (THICKO and no connection with current practises at LHR)

The advances in Ground Movement Radar have had no effect in low vis movements ?

Planes can land and take off in low vis - since Trident days. What is the issue ?

It seems that a little bit of fog stuffs LHR.

I understand safey margins, but it does seem that safety margins are taken to the extreme to perhaps further employment safety.

Jerricho
3rd Apr 2005, 00:38
LVPs require a safeguarded localiser area to ensure that ILS isn't interfered with. It can also mean problems for the jets getting off the runway with the reduced vis. Did you read the post by overstrees before your "well thought out post"?. A low-slung biz-jet can take an eternity getting off the runway in good weather (I lost count of the number of times I had an arrival come back because of this). Low vis??

All this requires increased spacing on final approach (increased from the standard 3 miles to 6 miles). It also means CAT III holding points are used clear of the sensitive area, thus meaning further to taxi for line ups. Conditional line up clearances can't be used. Like anywhere, both affect the departure and arrival rate.

Gonzo
3rd Apr 2005, 09:24
LL34, if you visited the tower at LHR I doubt you'd think our SMR that advanced. Sure, sometimes the labels are attached to the correct aircraft, but sometimes you get them flying about all over the place, attaching themselves to vehicles, terminals, all sorts of things. And that's not counting the poor performance of the primary radar in thick fog or heavy rain (d'oh! Just when you need it to work!). Not to mention the constant stream of cars that seem to be crossing 09L/27R, but which are in fact in the access tunnel!

Del Prado
3rd Apr 2005, 10:02
Halo, thanks for the correction (I always seem to get that one wrong)

Gonzo, to take you back to part of WHBM's question.."What would be the anticipated LVP flow rate for mixed mode ?"
Surely during LVPs we could increase the movement rate towards the 'normal' average of 80 per hour without coming close to swamping GMC ?
10 mile spacing on both runways (mixed mode) would equate to a landing rate of 20ish per hour plus 20 departures per runway equals 80. What do we manage at the moment during LVPs - about 65 ?

I know there are other issues involved but there would still be some increase in capacity, no ?

Gonzo
3rd Apr 2005, 10:47
Well, if you can get BAA to abolish the noise restricions, work out how we would do it on easterlies, and work out some way to do single runway 27L (glide path considerations lining up from the south) and 09R (remember where S7 is?) :ok:

Del Prado
3rd Apr 2005, 19:36
(remember where S7 is?)

No mate, don't have a clue about the airport layout. I'm sure tower visits used to be an SRG requirement too.

Gonzo
3rd Apr 2005, 20:56
Sorry DP, thought by the way you were talking you were in the tower.

You LL Approach?

Mister Geezer
3rd Apr 2005, 21:19
Just what is the state of play with landing traffic on 09R. I know it is very rare but I am only asking since I was a pax on a rather delayed flight a couple of weeks ago and landed on 09R at 2330L. Seemed odd since that is a 'noise sensitive' time?

Yellow Snow
3rd Apr 2005, 22:25
On easterly ops there is no noise issue for ATC for inbound aircraft. Whereas on Westerly ops you can only land on the departure runway a maximum of 6 times an hour.

If 09R departures controller isn't too busy he'll usually accept a T4 or heavy T3 lander to help approach out.

Jerricho
3rd Apr 2005, 23:23
On easterly ops there is no noise issue for ATC for inbound aircraft.

Aside from that quaint little palace thing sitting on a hill. ;)