Runway open?

[Christopher James]

Evenin' all. A procedure change at "London Airport":
Following an unfortunate incident upstairs the rules have been changed to prevent we approach chaps from vectoring you for a runway that hasn't actually been declared open again, following a closure. It used to be that we would slip a couple onto the other side whilst the post incident inspection was done but as of Monday that is no longer allowed. We have to go single runway ops. immediately which obviously has an impact on landing rates.

It is not uncommon for longhaul flights to consolidate(?) fuel and committ to Heathrow using the other runway as the alternate. The other day I believe there were 3 Pans and a Mayday in one afternoon which added about 20 minutes total to the delays. If it seems likely that you will committ to Heathrow, let us know early, eh.

It also impacts the night ops. with the work being done on 27R. We have to vector you for the other side and give you a change on the intermediate approach. I would hope that anyone on the ILS wouldn't be asked to change but these days we are being pressured by DETR only to land on the "correct" runway according to night time alternation. (For what it is worth we are also now required to keep you at 6000' until you are 20 miles from touchdown which is why the early morning guys hammering in through Clacton are often being refused descent.)

As if it wasn't difficult enough, trying to get a quart into a pint pot without spilling any!!
Happy flying, 09L :rolleyes:

[CaptSensible]

Hi there 09L. Thanks for that info.
I have another question about LHR rwys.
Can you set out the rules on rwy changeover times?
Why is 27R in ldg ops some mornings while others it's 27L. How is that choice made. And how is the decision made to switch 27R to 27L in later in the day?

[Fr8t M8te]

Thanx for the input 9L. Think I understood most of it.....well some of it!

Very much appreciate the help you guys and gals give under exceptionally trying circumstances at times.

Yes its me hanging on the fixed pitch props ensuring we make 1 sec past 0600LT whilst silver tonguing for the southerly RW ;)

regds

Fr8t M8te

[Christopher James]

Hi Capt.
Delighted to be of help.

Runway changeovers have become a thorn in our side over the last few months with the DETR introducting this night rotation. As far as mornings are concerned: One side is the landing runway for a week, then the following week it is the otherside and then back again.
The afternoon switch is done at 15:00 and lasts up to the last departure, after which we switch to the correct runway for the night period, subject to a maximum tailwind of 5 kts, runway dry and crosswind less than 12kts!! Got that???? Got that????

We are no longer allowed to use both runways in the early morning unless the delay is greater than 10 minutes between 0600 and 0629 or greater than 5 minutes from 0630 to 0700. It is really quite confusing for us and adds significantly to the workload at a time when we are running daytime landing rates with night time staff.

Oh dear, I've just realised this is beginning to sound like a winge rather than an answer!
Sorry,09L

[Capt Chambo]

09L,

Thanks for the information.
Could you answer a question that's been bothering me for years? Why is it that LHR will not (cannot?) give you a braking action report if requested? I ask because in periods of heavy rain and strong winds some aircraft types are severely penalised on x wind limits when the braking action is poor. This is to cover the RTO case. And some companies insist that if there is no braking action reported then the braking action must be considerd poor for planning purposes. The end result is either waiting, or asking for RW23.........never a popular move!

[Christopher James]

Afternoon Cpt Chambo.

Braking action is in the realm of the glass house and it is a few years since I was there. I believe there is no reason why you cannot have a braking action report if you give early enough warning. It is carried out by HAL ops using a mumeter (often u/s!), it obviously requires access to the runway and I suspect that is why there is reluctance.
It is my opinion that at Heathrow in particular we are cutting corners on safety in order to satisfy the demand for movements. Our runways are oversubscribed to the extent that we cannot accomodate a reduction in the landing rate for any period of time. The redundancy, which ATC use for safety, has all been used up for movements and it is forcing us all into a "push it" culture (one of the reasons behind the well publicised incident with the B747 and the A320).
Rw23 is the same. The crosswind requirement for its opening has been deliberately increased so that we will hardly ever have to use it thereby "safeguarding" the essential landing rates. It is perhaps not so bad in dry condidtions but I believe in wet and gusty conditions we have gone too far. A B747 did run off 27R last year in such conditions when in my opinion 23 should have been in use. The captain was told it would mean a significant wait.
I'm afraid all of us in the aviation industry are suffering from governments' unwillingness to address our runway capacity shortfalls. It is up to us to insist that we do this thing properly. If it were down to me I would insist.
Hope that helps.
09L :)

[Gonzo]

On braking action:

Basically we in the tower get told if the braking action deteriorates by the airport authority. However, they only discover this by doing a grip test down the runway which 'takes up to 20 mins, never less than 10 mins.' A run in each direction is needed without interruption. At no stage in our manuals does it say when we should request a grip test, so one assumes that the airport authority would know when one was required(!).

A similar situation exists with the runway surface condition. This data again will be communicated to us by the airport authority, but this has never happened whilst I've been on duty, just as I've never seen a grip test ocurr.

All seems to go on 'unofficial observation from the control tower'.

Gonzo

[vertigo]

A hypothetical question :
What if there was a crane in the 27R undershoot, making it unavailable for landing (on one hour recall).
Wind was such that 09L/R was not an option and delays were 25-30 mins. If 27L went out of service for any reason, what would happen to the holding traffic and would any aircraft have already 'committed' to Heathrow ?

[tired]

Thanks for the gen 09L, it's very useful.

A quick question - how "early" is "let us know early" if we commit ourselves to LHR at the end of a longhaul flight. We usually make that sort of decision in the hold, whilst admiring the fine English countryside - is that early enough?? ;)

[Christopher James]

Hi Chaps
The crane is notamed and so in theory you are supposed to be aware of it before getting airborne. However, on at least one occasion it was errected without ATC knowledge. Even if you do know about it, should somebody have an emergency which denies us that runway (even for a short period whilst the mandatory inspection is done) the new rules will cause extra delay and might make your situation crirical.

The reality is that if such circumstances were to occur we would be forced to land the committed traffic first and in theory sterilise the runway ahead of it. That would of course dump significant extra delay on everybody else which may put them into dificulties and there would be pressure on us not to do so. It did happen once before when a captained explained his situation and asked for a sterile runway. It was refused by our management. In the kak?

It is another angle on the redundancy argument. We just don't have the redundant runway infrastrucure available to us that our level of traffic requires and it is leading us into a "push it" culture. We are not in fact putting safety first.

Tired. You can probably work out now what 'early' means. We need to know if you are even close to fuel critical so that if we end up with a potential runway closure requiring single runway ops. we will already know who is tight. I would say first call with LL is late enough. :confused:

[Capt Chambo]

09L and Gonzo, thanks for all these little pieces of information.

I wasn’t aware that the wind limit had been raised before R/W 23 came into use, to save me trying to look it up next time I am at work, what is the present wind reading requirement before R/W 23 is used?

I did hear a little whisper that R/W 23 may be withdrawn anyway!

Regarding the utilisation of the runways: Whose idea was it to raise the landing weight category of the B757, with the subsequent need to increase the spacing for following aircraft if they are classified as a lighter landing capability?

Would it not also be a help if there were a few more conveniently sited high-speed exits off the landing runways? Currently the dilemma is whether or not to ease off the braking and roll to a high speed exit, or keep the braking going enough to slow it right down to make a 90 degree turn off, in both cases I suspect the time actually spent on the runway at the moment is much the same, but by converting some the 90 degree turns into high speed exits, I am sure you could significantly reduce the times that aircraft are on the runways. You might even be able to get the work done whilst the runaway is closed at night for resurfacing!

[Gonzo]

Chambo,

Our books say that 23 should be selected for use only when the mean crosswind component is 25kts. Activation procedure is said to take 3 hours, but I'd be surprised if it was that quick, considering all the a/c that would need to be relocated.

The books just say 'crosswind', so one assumes that means a wind of 230/25 is not sufficient, and that 180/25 would be needed?

On the need for high-speed turn-offs, I don't think the BAA would consider them as comercially viable, regardless of their usefulness.

Gonzo.

[Warped Factor]

Capt Chambo,

As I understand it, a few years ago when we routinely positioned 737's and the like 2.5nm to 3nm behind 757's, such spacing accounted for something like 75% of all reported arrival wake vortex encounters at Heathrow.

Further studies here and in the US I believe found that the 757 generated significantly greater wake vortices than might have been expected for its weight hence the creation of the Upper Medium wake vortex category in the UK into which the 757 moved along with a few other types. I think the US and others treat it as a Heavy.

There aren't a massive number of 757's operating out of Heathrow so I don't think they affect capacity in any great way.

WF.

[Christopher James]

Good evening Capt. Chambo

Many years ago the limit for R23 was 15kts; then, when they removed the ILS to make way for the whisky stands it was increased to 20 and then 25kts. It is a mean crosswind component that matters, so at 230 degrees it needs to be at about 40kts. Gusts don't count either :( which I don't understand. I understand that and aircraft doesn't have a crosswind limit, it has a maximum demonstrated crosswind ability. But what were the conditions under which it was demonstrated? 25 kts crosswind in daylight with a dry runway might be okay, but a gusty 25kts on a wet runway, late on a dark evening sounds completely different to me. As I have said before I believe the limits have been set too high and there is eveidence to support that view. The difficulty with closing 23 (which HAL would like to do) is that politically one is seen to be closing a runway. The people in my ops. tell me that DETR don't understand that it isn't continuously useable in combination with both of the others.

As far as the B757 is concerned, it was upgraded because its high lift configurement are notorious for producing intense vortex. I have often had heavy aircraft complain about it.

09L

[Christopher James]

Regarding fast turen offs, you are right, I believe. Two problems: 1. HAL probably won't make that investment because they won't see sufficient benefit (we re at minimum spacing now). 2. The r/t loading on 120.4 has been measured during trials at about 95% during peak times. That already leaves insufficient slack in my view to allow for errors, missed calls and problems. Packing you in tighter so that faster turnoffs became necessary would make that worse still. It's not that it can't be done (some often do now), I just believe it is another step too far. I maintain that it is not our job to make up for governments' unwillingness to provide us with the runway capacity we need.

09L

[Lew Ton]

Wet Runways

In the UK we cannot use a Griptester (or Mu-Meter) to measure braking action on wet runways as it is considered unreliable. Therefore you are left with the descriptions damp/wet/water patches/flooded/sea planes only :D (I cannot bring myself to say the runway is 'wet, wet, wet'. 'Wet, all thirds' is better.)

B757

I thought the reason that it was put into a Upper Medium Category was that although it produces vortices equivalent to a Heavy, it itself is not as tolerant as a Heavy behind a Heavy Iif that makes sense.)

[CAT MAN]

Great insights "ZeroNine left"...YOU GUYS AND GALS do outstanding stuff,amazes me how it's possible to stay on the ball...

[YoungAndyMac]

Thanks All, a most interesting thread!
Do I still want to work at LL when I grow up?

[Capt Chambo]

Warped Factor:-thanks for the information regarding the Boeing 757. I recall the survey being carried out about the wake vortices that are generated by the B757. I can’t lay my hands on the magazine at the moment but I seem to recall the Boeing “Airliner” magazine published an article about their findings. If I remember correctly it was something called a “Tangential Vortex” that was out of proportion to the weight of the aircraft, and this is what causes the problem. The statistics you have are fairly conclusive, my own experience of following B757’s around the UK and Europe are that they are really no better or worse than anything else. Once you hit vortices you just deal with them. I couldn’t quantifily say one type produces a stronger vortex than another. As you also point out the problem largely solves itself at LHR as BA dispose of their 757 fleet.

09L:- thanks for the information regarding the X-wind limits and R/W 23. I take your point about the loading of Director on 120.4. But (at risk of oversimplifying their job) once they have you spaced correctly, and doing 160kts to 4DME, they can hand you over to the Tower. The point about more, or better sited, RET,s is that time spent on the runway itself would be reduced. For instance, your namesake 09L. The constant dilemma is whether or not to keep the speed on and roll to block 16 or 17 where we can leave at 20+kts, or whether to brake harder for a block 14 or 15 which, both being 90degree turn-offs, require the speed to back to less than 10kts. Now if there was a high speed turn off around about block 14/15 I believe that it would be a great help especially for aircraft who will be continuing Eastabout, in that they get off the runway at a higher speed leaving it free for you to land another one. I accept that in this example it’s not so convenient for aircraft who will need to taxi Westabout for their stand, but I hope you see my point.
Do you have any statistics for Go-Arounds that are caused by aircraft failing to clear the runway in time? It may be of course something along the lines “…if it ain’t broke…..” and more high speed turn offs are, statistically, not required.

Lew Ton. Thanks for the information about grip testers, mu-Meters, and wet runways. I believe the B757 is still classified as a medium for determining it’s required spacing when following traffic, but when you are following a B757 then it becomes an Upper medium.

Finally can I express my thanks for all the people who work in the ATC, particularly at LHR. Their professionalism, patience, humour and understanding are much appreciated.