Reduced Occupancy Times.

[forget]

Tech Log would seem to be the place to ask for educated opinions on Reduced Runway Occupancy. Specifically, I’d appreciate any thoughts on automatic Clear Voice advisories of ‘distance to go’ to (controller selectable) exits. Please see http://www.axis-electronics.com/pdf/gm_reduced_runway_occupancy.pdf

Taxiing times will, of course, be extended during LVP’s but it seems (to me) that the one single element on airport capacity is the extended approach separations to allow for longer occupancy times. Thanks in advance.

PS. I’ve obviously got Heathrow’s current condition in mind here.

[BOAC]

Well, its clever, and will save a bit of time. The only doubt I have is whether it will actually make a significant difference to landing rates, in view of the times saved which vary between a mini 6 seconds to a good 21+? ATC would need to work out the actual increase in runway utilisation given an average improvement of, say, 10 seconds or less per landing over the LVP period, remembering that not all a/c or crews will be either briefed/able or equipped to use it to its maximium benefit.

I was involved in the set-up of the LGW RETs and sadly have never seen an analysis of any improvement in occupancy post installation.

I'm really not happy with the last sentence of P1 para 5. I think that should be crew selectable.

EDIT to say that should read LGW RETILS:ugh:

[forget]

Thanks BOAC, that’s just the sort of input we need. :ok:

As for potential time savings, we can use simulators all we like but only real life ops will show what is achievable. But from what we’ve already seen in sims – possible savings are significant.

.......... remembering that not all a/c or crews will be either briefed/able or equipped to use it to its maximum benefit.

All aircraft and crews are equipped to receive the call outs. Just switch on MKR Aud during approach briefing. (It could even be left on permanently for UK ops as only one civil airfield now has a (single) Marker Transmitter, and there won’t be many left in Europe.)

Should an airfield equip with the system it would be operational full time, which, I like to think, would allow crews full familiarisation in daylight clear blue so that when it is really needed they have the confidence to use it.

............I'm really not happy with the last sentence of P1 para 5. I think that should be crew selectable.

I take your point but, technically, control has to be from the ground. I suppose a crew could nominate a preferred turn-off which is then selected by the controller. Any good?

Thanks again.

[Musket90]

LGW has RETILS (Rapid Exit Taxiway Information Lighting System) installed on it's RETs. They provide a 3-2-1 countdown of lights/paint markings spaced 100m apart starting at 300m from the start of the exit point. Runway occupancy data before and after installation confirm they have reduced runway occupancy times since being introduced.

STN intend to introduce the same on it's RETs.

It helps when designing runway exits that they are in the correct location which suits the type of traffic using the runway therefore reducing runway occupancy. Busy airports with long runways which have a mix of small, medium and heavy traffic should provide 3 exits with the first at around 1400-1500m, second around 1800-1900m and third around 2100m from the landing threshold to help make best use of the runway.

[BOAC]

Forget - that sounds pretty simple and universal. Don't 'forget' though, in terms of getting it to 'work', how many crews still check in on Director at LGW and LHR with more than callsign.

Regarding t/off selection - yes - I wish to nominate that. There is no way ATC can tell what suits my a/c and my f/deck on that day. I suppose if we went for a similar RET policy as LGW R26 - ie mediums are expected to take FR - that would be ok, as long as turbulence/windshear/weight/tech issues are taken into account. Much better to have a standard quick 'word' on check-in with director/tower eg 'XXX 1234 for FR'

[HEATHROW DIRECTOR]

<<that the one single element on airport capacity is the extended approach separations to allow for longer occupancy times.>>

Just a little point - in LVPs the extended spacing is primarily to safeguard the localiser. Additional runway occupancy time is easily contained within that requirement.

[BOAC]

HD - if the time for the landing traffic to clear the sensitive area could be reduced, could not the 'spacing'?

[forget]

Now that Yuletide is behind us I wonder if we may resurrect this. HD - you there?

[26left]

BOAC & Forget
As one who was also involved in the LGW RETILS and the FR turn off. I can confirm that occupancy times reduced subsequent to the introduction of both initiatives, enabling consequential capacity increases to be introduced.
Reduced occupancy times allow reduced final approach spacing, subject of course to Vortex Wake minimum requirements.
Use of MLS in LVP's should enable reduced final approach separation as the MLS signals are not distorted by aircraft/objects on the runway.

[BOAC]

What would be the chances of someone funding a 'good weather' trial at LGW?

[forget]

What would be the chances of someone funding a 'good weather' trial at LGW?
Now there's a thinking man :ok: .....but slender I feel. :(
BOAC, If ever you have few minutes to spare in the sim I'd be pleased to let you (or anyone else) know how a very simple 'suck-it-and-see' can be rigged. I know most of it's obvious but there are one or two subtleties which save sim time.

[spocla]

On a similar note, can anyone point me at a reference to settle a recent debate in my company. The question is this, once cleared something like "after departing BA A320 line up rwy 27 R via A1", can one taxi beyond the Cat 1 holding point/A1 (or another , earlier taxi clearance limit) to get close to the turn on for the runway in question-thereby reducing occupancy time to rolling (notwithstanding wake considerations) or must one wait until the said A320 has started his T/O. I've seen both techniques being used at LHR and would like to know the facts.