Actually, enroute needs to know too. That is how we can tell just what an aircraft can do. There is a big difference between the 732, 73Q, 733, 737 etc...

regards

Scott

LLC,

In that case I stand corrected.
Excluding the Northern Runway, where are the taxiway restrictions at Gatwick for different types of 737 ?

I do check the different type of 747, but to the best of my knowledge, we've never been asked to check other variants.
Indeed, I've discussed this a couple of times when the type change has been A320 to A321 or vice versa and the tower controller said it didn't really matter.


BOAC,

170 to 6 (for example) would work for all jets.
However, inside 6 dme an emirates 777 might slow to 160 and the 737-500 ahead might slow to 120. Thats 50% faster over nearly six miles. We'd have to increase the spacing between arrivals and the movement rate would suffer.

The bottom line is the efficiency of the runway and while it might be 'nice' to let you all fly the speeds you want, the airlines (not least BA) are not prepared to pay the cost of losing 4 or 5 movements per hour.

If, on the other hand, we have a stream of 737s and they all request 170 kts to 5 then that's easy to provide, good for the enviromentals and most importantly the landing rate does not suffer.

It just depends on the circumstances, that's why I think 160 should be the norm, but we should provide 170 when able and when requested.


I'd be very interested to know how many of the 737 flights into gatwick have to drop the gear to achieve 160 and whether that is dependant on variant, weight or operator. It's been discussed many times but we don't have a definitive answer.

737 restrictions at KK
 

Various restictions around the airfield. Such things as what can park on the remote holding stands, whether X can pass behind Y when one is holding at a holding point.

Similar restirctions apply to airbuses (320/321).

Del Prado. The speeds the aircraft slow down to should not be a problem. Slowing down at 5/6 miles should let the aircraft pass roughly 160/150 at 4 dme slowing to their final app speed. Although sometimes I wish it was the case a 737 cannot slow from 170 to 120kts instantaneously!
p.s. without exception every -3/4/500 operator will drop the gear if required to keep 160 kts. Unless they are deaf.:D

DP - ALL 737 3/4/500 will need the gear for 160kts. This restriction can (apparently) be lifted when a Boeing rudder mod is incorporated, but BA (and I suspect most) operators will wait until their WHOLE fleet is done before changing the speed restrictions piecemeal.

This current 'issue' was triggered by a specific very early speed reduction request. Gear down at 18.5 will probably double the overall fuel consumption for an approach. We (BA) are ??normally?? putting gear down at between 5 and 7 miles on an unrestricted approach (standing by for rhubarbs!), so if the speed requirement is not too far away from that, 160 to 4 is a doddle! It is trying to satisfy ALL the inputs that is difficult - yours, ours, 'airfield neighbours' and the accountants!

FYI, at normal weights, flap 5 has a lower limit of 180kts, flap 10 170, and flap 15 150, but requires gear down. These figures are for the 737 3/4/5 and I detect that the NG 737 has different speeds. We have heard nothing form the AB319/20/21 brigade yet.

It is very unusual to have an approach speed of 120kts in a 737. 140 is more normal.

I work Essex radar and when I can I do try to offer the B733's 170kts to 5 DME OR 160kts to 4DME and let them decide.

Granted at the end of the day I don't always offer it to everybody as there's not always the time but I'm happy if they ask.

I suppose at the end of the day it's down to the controller but my theory is that it can't hurt to ask. I accommodate requests when I can, I can't do anymore than that. That's just me though, I can't speak for other controllers or sectors.

:)

The 'asking' seems to be working at LGW at the moment. It does generate extra R/T, and the difficulty for me is in knowing whether it will be relevant i.e. whether it would be applied at around 10-11 miles, when it really doesn't matter that much (160 - gear or 170 - no gear), or whether it will be a 'surprise' at 18.5 miles finals in a 60kt headwind when it does. Finding the right form of words is a trial too!

I offered every single 737 I spoke to at Gatwick yesterday the choice of 160 to four or 170 to five, and that was quite a few :)

The outcome was that two or three came back with "we'll do 170" and all the others said "we'll do 160".

Distances from touchdown when offered were anywhere from around 16nm out to around 8nm.

I offer no opinion on this other than what I originally said, that there does seem to be a lack of consistency. But if you specifically want one or t'other plase ask, preferably before turning base.

WF.

WF - I appreciate your interest in this:

I cannot be sure, but that may well contribute to the perceived 'inconsistency'? We have NO SOP, except that we try to minimise noise and conserve fuel, and this really is the point of my post. It doesn't matter 'a fig' from the handling point of view. The only 'fixed' target is to be in the approach config. with speed around target approach speed at 1000'AAL, i.e. just over 3 miles. This may have been the earlier problem you referred to with a light a/c = low approach speed - accepted some notice would have 'professional'!

As I said above, 160 to 4 requested at 8 miles is a total non-event. Requested at 18.5 with a G/S of 98kts is not.

Oh for some more famil rides!! As an aside, what is happening when you guys and girls ask for them? I am not seeing any arrive at the f/deck door :confused:

BOAC,

The NATS fam flights scheme stopped following 9/11.

I think they're back on the agenda now but the days of us just asking when on board if we can sit up front are gone I suspect, any we do now have to be arranged through official channels weeks in advance.

I recall seeing something about a very limited number of BAW trips available for TC folks recently, but can't remember any details.

WF.

Sorry, WF, I misled you - I was not talking about 'ad-hoc' f/deck visits, but officially arranged ones. I understood from a thread here post 9/11 that they were 'back-in-business' and I was wondering what the response to those requests was? There is certainly no problem in our carriage as long as the 'official' clearance has been obtained- and I'm sure I speak for all when I say we'd be delighted to see you all - well.......not ALL (at once):D