Microwave Approach

[ukdean]

Just a quick question.....

Currently tuned in on LHR approach when a speed bird asked for a microwave approach. Can someone inform me what this would be.. Thanks for your help............

PS makes great listning to the guys at LHR......:D:D

[Doug E Style]

It's one where there's a loud "bing" when the aeroplane lands.

[Moira]

Check this (http://en.wikipedia.org/wiki/Microwave_Landing_System)

[ukdean]

Moira,

Many thanks.....

Hope you have a happy festive season

[ComJam]

I recently Flight Checked the MLS system at LHR, it's the only "operational" one in the UK, but, it can't be used "in anger" and is still only a trial with BA and us being the only aircraft with the system installed and in use (i think!).

There is no UK wide installation taking place as suggested by the Wiki link and MLS is currently playing second fiddle to FMS / GPS approaches as the future of Instrument Landing Systems.

Not that there's much wrong with the modern Cat 3 ILS :ok:

[Megaton]

Except, Comjam, that greater flow rates can be achieved in LVPs with uwave approaches so for an airport like LHR they are a significant improvement and offer BA a competitive edge when the wx turns. Furthermore, uwave equipped aircraft will be able to land on the departure runway in LVPs since the protected area for the uwave installation is much less sensitive than for a ILS.

[ComJam]

Absolutely, that's why I said "not much wrong with.....", we could go into what is better about MLS over standard ILS....but i don't know if it's ever going to actually enter full service. It's been installed and sporadically flight-checked for a few years now but is there any progress being made?

[Megaton]

I've done several uwave approaches in recent weeks. BA reckon that, had it been operational last winter, it would have paid for itself in several weeks. Can't imagine that BA/BAA would have gone to al that effort for nothing.

[2 sheds]

μwave, not yoo-wave!

[Megaton]

Too lazy to look for the correct symbol.

[Thunderbug]

MLS approaches available on all 4 runways at LHR. BA are installing MMRs (Multimode receiver) on the A320s & A321s.

The MLS approaches have been available for use since summer 08, but only to managers and trainers. Since 01 December it is open to all BA Airbus crews with the limitation of a 1000'AAL cloudbase.

The facilities are approved for autoland, but only currently CAT1 certified. Data from the approaches are being analysed for an eventual CAT3 approval. The critical path is the proving the reliablity of the ground equipement; a mean time between failures hasd to be proven before the CAA will allow CAT3 approaches.

Apparently if MLS had been available during that foggy period just before Christmas 2005 it would have paid for itself as there would be less cancellations and disruption for the Airbus fleet

T'bug :ok:

[Roffa]

As long as they don't think they're going to be able to queue jump, which was their initial thinking I'm led to believe...

[HEATHROW DIRECTOR]

<<Except, Comjam, that greater flow rates can be achieved in LVPs with uwave approaches so for an airport like LHR they are a significant improvement >>

Sorry, I'm out of touch, but how could greater landing rates be achieved? Is it because MLS requires less protection?

Thanks.

[Roffa]

Affirm, HD.

[danieloakworth]

Eurocontrol/Nats/BA have been working on a project for several years now aimed at increasing flow rates at LHR, during LVP, using MLS. It's aim is to optimise the smaller sensitive area by using a trigger line that once passed will allow landing clearance to be given to the aircraft behind.

[5711N0205W]

Thought that tickled the memory banks, a bit of digging turns up the link below showing a form of MLS being used on offshore oil platforms in 1979.

not sure if this is exactly the same, look at the bottom of the page;

boeing | airbus industrie | 1980 | 0783 | Flight Archive (http://www.flightglobal.com/pdfarchive/view/1980/1980%20-%200783.html)

[simfly]

As long as they don't think they're going to be able to queue jump, which was their initial thinking I'm led to believe...

I can see how some will take it that way, but if BA have the equipment to get more aircraft in, surely it will have a benefit to everyone else too as runway utilisation improves. BA are always the airline who's stats are mentioned and criticised when there's cancellations etc regardless whether it's their fault or not, but if BA are doing their bit to improve things, I hope they get recognised for that also!

[Roffa]

It's not to ATC's benefit if BA think they're going to be routinely coming out of the top of full stacks just because they've got MLS aboard.

There's little enough of an RMA to play with without for example also trying to get someone at FL110 out of BIG, when OCK is also full, because they've got MLS and the traffic below hasn't.

If they want to significantly increase workload and the likelehood of incidents as well as movements, that's the way to go about it.

If the idea however is just to TEAM in low vis, using the dep runway with criteria that are not as restrictive as with an ILS, then that is probably the way to go about it. No queue jumping out of the stacks required.

[HEATHROW DIRECTOR]

Roffa... but similar problems have existed for many years due to the different minima for various aircraft/crews/companies. Maybe that's not the case now? BA often used to jump off the top of the stacks because they could take 75m whilst those beneath might need 100, 400, even 1k! I seem to recall we managed OK, but it sure got the adrenaline flowing!

[Roffa]

HD, there are very few aircraft/crew combinations that can't land these days in what might be called routine low viz ops. I can't recall the last time anyone has said to me they can't take the RVR.

It's also one thing taking the occasional a/c out from the top of a stack, quite another trying to do it regularly with the entire BA minibus fleet.

It's not a sensible solution.