TIGER/WIZAD SID & other questions

[pax anglia]

(1) Looking at my Aerad guide I see that the above departures may be offered to aircraft normally allocated LAM/CLN SIDs and DVR SIDs (from Gatwick) respectively. Is this to spread the outbound load when a number of departures with ultimately the same routeing are offering, or are there other reasons?

(2) I'm rather puzzled by the existence of UR41 which appears to start (or end) at WCO. It doesn't seem to serve any practical purpose but perhaps it has its place in the great scheme of things. Can anyone advise ?

And finally.......
(3) I live fairly near the north west end of the BNN hold and frequently cast an eye on WOBUN departures from LHR. Very often they appear to be on a heading about 30 or 40 degrees right of the BUR-WOBUN track so far as I am able to judge. I assume this to be in order to get them going up the east side of "The Ambers" (there, that dates me !) and out of the way of the Bovingdon inbounds. However, very often no BNN inbounds appear so can anyone enlighten me as to why this tactic is employed, please?


Thanks in advance, Ladies and Gents.

[Warped Factor]

pa,

(1) Looking at my Aerad guide I see that the above departures may be offered to aircraft normally allocated LAM/CLN SIDs and DVR SIDs (from Gatwick) respectively. Is this to spread the outbound load when a number of departures with ultimately the same routing are offering, or are there other reasons?

WIZAD and TIGER departures are used tactically to expedite traffic as required.

Certain (noisy) aircraft aren't allowed to fly them.

Don't see them being used as often as they used to be, especially the WIZADs.

Ideal time for a WIZ might be to send a slow prop aircraft one way and all the jets the other so the prop doesn't hold up the jets, if you see what I mean. Not that many prop aircraft flying into Gatwick these days so not quite the same need to split the departures.

WF.

[Northerner]

I've also been know to use Tiger Sids when very heavy holding at BIG and LAM to allow extra track miles to climb, and also for bad weather....

[5milesbaby]

Might be wrong, but doesn't U/R41 join up with the outbound routes from Luton and Stansted at WCO to take them down to SAM and join U/N866? R41 is used in opposite direction for lower, slower a/c routing north that get onto A47 at WCO.

[vectorer]

Other than using TIGERs for an off-load SID, they are really useful if there is a strong southerly wind, 'cause the left turn off 26L allows the BIG sector controller(120.52) get some altitude on the departure and the turn is under better control turning into the wind. Bearing in mind that you've got to get above the BIG hold and be level FL130 by the extended LL centre line, or alternatively, stay at 6A under BIG & LAM, anything that gets the climb rate increasing is a useful tool to have.
BA KK can we have the "very good rate available" 737s back on the LAM deps instead of the RJs/146s..........please!!

[pax anglia]

Thanks everyone for your responses. Any takers for (3)?
Perhaps if I changed the topic title (not sure if I can do that) or re-post that particular point on its own, it might prompt a response, but thanks again one and all.

[zkdli]

some times the outbounds are on hdgs east of bnn because they are being positioned to go up the east side of b4, but usually it is to get a cross agianst the egbb inbounds or against the egss/gw inbounds. the northwest sector is now a very busy sector and the greatest amount of traffic on this sector comes from egss/gw ins and outs so what you are probably seeing is the tactical positioning against that traffic!:)

[pax anglia]

zkdli.......
Many thanks for shedding some light on that point for me.
Three questions all comprehensively answered. Could a chap really ask for more?

All the best....

[Baggy]

Pax anglia,

In general out of london, you quite often begin on the allocated SID, but then end up on radar headings from 3 or 4000' until much higher levels.

Dont think I've ever done a full SID from my home base (LGW)

[Hotel Mode]

Ref the Rj's out of KK, we can give you a good rate if we maintain 210kts, but that means not levelling at 4000ft otherwise we will accelerate, If i get cleared to 6000 on initial contact i will always give best rate, saves us time too. If we level at 4 or 5 I generally assume that you are busy and accelerate. Did an ABZ yesterday and was FL75 by abeam the Take off end of 26L and got a lovely short cut. The other thing is we cant accelerate past 250 until Fl80 but once we have got 300kts we can trade speed for height if you need it, just ask.

We'll all be in the regions by April so wont be too long anyway. We only get to know what you want by these boards, it would be great if there was more communication between ATC and Crew. I'm sure if a preci of your standing instructions out off kk was on the board we would read it.

[expedite_climb]

Hotel Mode - whats the min clean on the RJ then ? WHy cant you pull it back from 250 to 210 ??

[Hotel Mode]

We can slow down to 210, but I wouldn't do it unless asked to expedite, or, and i have done this recently, if we get a clearance to say F100. Sometimes i guess you might be trying to measure our rate of climb when you give 5000, 6000, Fl80, but I wouldn't wind the speed back unless it was positively going to help us, as it creates quite a high deck angle when the girls are getting their carts out, whereas if you maintain 210 at least they know what to expect!

[Vlad the Impaler]

The only KK departure that gives a levels headache is the LAM departure. Traffic on a LAM absolutely must at FL130 by the time it reaches the LL extended centreline. This is to provide some kind of separation against the LAM stack which it climbs alongside as LAM does not use FL130 to hold. If the aircraft is a dubious climber then this can involve running east as far as DET then a hard left turn to point west of LAM. This is also the initial standing agreement for CLN departures but they can be in the climb to 130 pointing east of the LAM holding area and the LAM controller then weaves his magic and jumps the LAM inbounds.

[pax anglia]

As the subject of agreed levels between sectors has been raised, I would be interested to know why these are not part of the published SID. Looking at various STARs there is a boxed paragraph with information as to expected descent clearance eg: ...FL150 by BNN 25d. It is emphasised that actual descent clearance will be as directed by ATC. Surely it would help if crews were informed what climb clearance was likely with the obvious warning to climb only when cleared. I have noted one exception to the rule, that of Compton SIDs from Luton which gives the expected requirement to cross CPT 11d at FL70 or above etc.
Any thoughts, Gentlemen ?