View Full Version : RNAV Arrivals to LHR

1st Aug 2003, 22:56
Have any of our BA 747/777 drivers had the pleasure of performing the new RNAV arrival into Heathrow at some un-godly hour of the morning yet?

Point Seven
2nd Aug 2003, 02:01
Get out more man.


7th Aug 2003, 00:57
At the end of the night duties last week I offered the LAM 1Z to a few BA crews and they took it on. I'm not sure how it progressed, however, as the guy in TC was being a bit awkward about them. " Far too difficult/busy etc". Would be interested to hear whether it made life easier or more difficult.

8th Aug 2003, 23:50
Could somebody explain what RNAV is please?



9th Aug 2003, 02:13
Will no doubt fly one next week .

Why would TC be too busy at that time of the morning it is normally vectors to a long final for the 27s .

the RNAV app would mean more track miles at this time of the day but if it pays the way for this a busier times then I'm for it .

The problem early in the morning is that you are given decent clearance which puts you on the G/S . You therefore have to slow down way out or use speedbrake which is very noisy .

What would be great would be descent to 3000 ' at 20nm so you could keep 300kts then slow down thrust levers closed to 180 kts at 10 nm and hit the glide . Quiet and efficient but perhaps not all within CAS .

Perhaps not possible but that would be the ideal from a 744 point of view .

India Four Two
9th Aug 2003, 02:26

RNAV stands for Area Navigation.

Have a look at this Eurocontrol RNAV Concept (http://www.ecacnav.com/rnav/default.htm) document.

Kalium Chloride
9th Aug 2003, 02:42
Could somebody explain what RNAV is please?

RNAV is the technique of using positioning data to allow an aircraft to follow a pre-determined flightpath with a particular degree of accuracy.

Instead of following a course defined by conventional ground navaids - which might involve flying an inefficient flightpath - an aircraft in RNAV airspace can fly more directly from A to B by using its own on-board navigation systems to keep it on track.

9th Aug 2003, 06:51
The reason TC can be "too busy" is because the route involves clearing the ac down to almost min stack E of logan amonst other factors such as shall not delay other traffic etc, pretty much unless it is the only thing running in to Lam you cant approve it, likewise by the letter of the law if you want to issue a second arrival the Prnav procedure the first a/c must be with LL apc and be confirmed off, so it really only needs a couple of arrivals for it to be too busy to use this procedure, even though it is relatively quiet. Also AC should not be clearing the ac for these arrivals but be transfering them in plenty of time for TC to do this i have experienced a couple of crews who were under the impression they were cleared for this approach on first contact with TC.

9th Aug 2003, 16:01
See P7, people do want to talk about this!! Nah-nah!!

We have also been told that BA ets performing the STAR shall not delay other inbounds like MacDoris explained.. We have had instances of some a/c starting the procedure then being vectored in the later stages so not to slow others down.

It does seem to work if you have a a bunch coming in, and the last one is BA.

Kfw makes and intresting point. While the trial requires quite a few jets to do the procedure, there is the issue of "I can offer you straight in at high speed" or "You can do the procedure at standard speeds and increased track distance".

9th Aug 2003, 18:32
Tks Mcdoris ,

The 28 and 26 arrive before the night curfew hence I thought it would not be busy .

Most controllers will be aware of this but for those that aren't....

I'd prefer fewer track miles and a straight in , but if you want the speed kept up we will need to be below the glidepath as you cannot slow down easily once fully established . Speedbrake wastes the a/cs energy is uncomfortable for the pax and creates considerable aerodynamic noise for our neighbours . Descent below 4000' only @ 12 nm would mean slowing to 180kts + /- the wind component . If you need to change your mind and slow us up earlier than anticipated then thats no problem we would just reduce ROD and trade ALT for less speed .

9th Aug 2003, 20:02

If i could i would launch all the arrivials i can to 10mile final and 3000 ' (other traffic permitting of course). Indeed it makes life straight forward in the early hours so if you dont want to do the prnav then great tell me, as far as speed i generally let you fly the plane your better at it than me or so i believe so if i do need to restrict your speed i tend to ask the pilot to tell me when he (or she ) begins to reduce or even better use another form of seperation so speed control is not needed. We cannot descend to 3000' anymore due noise so you have to make more noise just higher up. The 26 and 28 are good candidates for the procedure but i would prefer to be on the ground sooner so thats why we offer you the choice. The thing with the Prnav arrival is we are not supposed to have you on headings, not really to restrict your speed and if possible not have stop off levels so it can be really quiet with only 1 or 2 arrivals but due to their position prnav may not be an option. Clear as mud or am i now just rambling? Its the heat you know.

Warped Factor
9th Aug 2003, 22:30

If you don't do the PRNAV approach but rather a straight in at that time of the morning, there are still the other noise restrictions to contend with.

These effectively mean not below 6,000ft until around 20nm from touchdown and thereafter trying not to descend below the glideslope, ideally continuous descent all the way to touchdown but whatever not less than 2nm of level flight IIRC, minimum 10mile final and not below 3,000ft unless established on the ILS.

None of which is compatible with diving down at high speed and then closing the throttles I suspect :(


Capt H Peacock
10th Aug 2003, 01:53
Trial PRNAV procedures from 12th June, AIC SUP S12/2003 refers. Only operators involved in the trials will be offered these approaches.

Initially there's a LAM 1Z STAR followed by a WINSR, BARNS, RICHY, or MARLO transition. So now you won't be surprised if you hear these on the R/T.:ok:

Fright Level
10th Aug 2003, 18:53
The Lambourne 1Z RNAV procedure pretty well follows how you'd be vectored on a normal day. The trial is simply an experiment to satisfy ATC that pilots can keep within the narrow track, height and speed parameters in preparation for an "Estuary Arrival" which is your 12-15 mile straight in for 27.

The LAM1Z will probably be never implemented "for real", LHR is just too busy for that other than at 5am.

Point Seven
10th Aug 2003, 23:13
Maybe it is being developed to provide a quiet effecient approach for use between 11PM and 5AM if, maybe, Heathrow got an icreased flow rate on the nightshift?

More planes, but not so busy as to need radar vectors.

Sensible, n'est-ce pas?:eek:


10th Aug 2003, 23:27
Point seven - nearer the truth I believe, and apparently there are manning implications for the LHR TC function nightshift, which is one of the reasons NATS are so keen, if you know what I mean. (Or so says my neighbour who just happens to be one of your managers.)

11th Aug 2003, 02:25

Perfectly clear Tks

Warped Factor thanks for the info .....

Ironically keeping altitude will only keep the noise down if speed is reduce to an intermediate flap position about 180 kts clearly not ideal 20nm out .

You cannot decelerate on a 3 degree slope very easily . The only options are to put the gear down or throw out the speedbrakes both actions create noise , aerodynamic and in the case of the gear engine noise too as the engines spool up to prepare for a G/A.

If you descend to 3000 ' @ 20nm slow to app speed to intercept the glide from below in level decelerating flight , then follow the glide from 3000 ' , carefully judged you should have the thrust levers closed to 3.5 nm . I believe that this would be minimum noise as opposed to following the glide from 6000' not to mention more fuel and time expeditious .



11th Aug 2003, 06:04
We have been told (off the record of course) its more to do with proving how accurately the routes can be flown for use elsewhere in the world???
Not aware of any serious staffing problems at LHR TC during the nights as special still has to be manned etc you are not gonna get rid of them. As with all the sectors as the traffic picks up in the morning so more bodies are available.