Hi guys, Do any of you know why MLS is not being implemented in civil aviation?ILS is old, and has alot of (buggy) side fx(like distortion due to fm radio broadcasting).MLS has alot of potential, and in my opinion could solve alot of those 'noise abbatment' issues we've been having(for EBBR at least).Is there a factor I might be overlooking?Any information would be welcome. Though I allready know the basics about MLS(and that is not JUST knowing it stands for Microwave-Landing-System :-p)thanks in advance

Everything in aviation takes a long time to happen, due to the enormous costs if certifying a new system.For an MLS system to be installed at an airport it would cost much more than simply purchasing an installing the equipment. The equipment would then have to undergo months of testing and certification, new approach charts would have to be designed and tested. Airlines would have the install MLS recievers into their aircraft, and certify them for use. Pilots would have to undergo training and checking on the new system.At the end of the day all the costs associated with this will be passed onto the user of the airport.... the airline. Airlines aren't in the business of spending money they dont need to, so they will do a cost/benifit analysis of the new system. Will installing an MLS save them money through less missed approaches, or more efficient approaches? The answer is no, as current CatIII ILS systems have an incredibly high reliability rate.Unless there is an obvious cost saving in a new system no one will support it.A similar scenario occured at Sydney airport, which was looking at installing a cat II or III ILS system. The airports corporation did the research and came up with an estimated cost of the system. This was then given to the airlines who determined whether the reduced number of missed approaches and diversions due to weather would save enough money to offset the cost of the ILS. The answer was no, seeing as we have so few days a year with weather bad enough to cause diversion, so we still just have the Cat I ILS.

My understanding is that MLS was going to be the instrument landing system of the future, enabling precision curved flight path approaches, etc. until GPS came along. The U.S. backed away from MLS as soon as it became apparent that augmented GPS could do that much and more.

yet GPNSS is not internationally allowed as precision instrument?HPSOV is indeed correct, but as social problems are really starting to arrise, and i expect that to start happening all over the world(noise problem). ILS is great, neverthless our society advances so i thought the airlines would maybe consider MLS any time soon.But i see your point in the financial analysis being negative at this time, i just wonder what'll have to happen to make that change?cheers

It isn't just the airlines. In fact, I don't think they were even the main drivers in the decision to back away from MLS. That decision was made by the U.S. Government (FAA), who would have to make very significant capital investments in the equipment necessary to support MLS on the ground. GNSS is the replacement.I'm not sure whether Europe continues to embrace MLS.See FAA Plan

About Europe's current vision about GNSS systems is that it isn't considered a Precision Approach. But they're not actively involved in MLS i think. Maybe it'll first serve european military aviation...btw, the reason Europe doesn't want to 'rely' on GNSS is that the entire system is controlled mainly by the US armed forces.But i'm not 100% sure about that.Cheers

"btw, the reason Europe doesn't want to 'rely' on GNSS is that the entire system is controlled mainly by the US armed forces"That's not the only reason Lenny. One of the main reasons that it isn't approved for precision navigation is that we don't have enough information on how the signal can be interfered with, be it intentional or not. The EU's GPS system wil not be immediately approved for precision navigation either. It will require a lot of certification etc.But GPS is definetely the future for navigation. Already entire aircraft families rely solely on GPS for RNAV capabilities (ATR's).RegardsMark

I believe they are looking at the possibility of installing ground stations near the airport, that will act a dummy satellite in order to improve or check the accuracy of a GPS signal, as the ground station will be of a known location.Here is an overview-http://www.airservicesaustralia.com/servic...%5Fbrochure.pdfAnd a much more technical paper-http://www.airservicesaustralia.com/pilotc...sheets/gras.pdfI also wonder if anyone has any info on what I believe to be the first precision GPS approach, currently in use on Norfolk Island?http://www.airservicesaustralia.com/pilotc...SNFGP03-073.pdf

I Know BA purchased some equipment, was a long time ago though.Projected capabilities of future GPS systems would allow something similar to what the MLS does, without the extra cost (Equipment Is the only thing I can think now)As far as I know, the FAA, was installing MLS systems back on the days. No one bough MLS equipment. Consequently, no one used the MLS. Those systems today are mostly "gone".It seems ILS will be here for a long time, because I don't think that with today's airlines financials problems they would like to buy new equip. That's what I think at leastCya,Bruno Francescoli.

The 7 767-300's we are leasing from BA have MLS antenna fitted. Not sure if its hooked up to anything though!

Would be great if you could check that out ;o ...Best,Bruno Francescoli.Miami, FL.

Lenny,One International Airport will soon have MLS installed.There is a full debate on it in the ATC section of www.pprune.orgjust do a search for MLS and you will find it.And the airport in question:-EGLL - LHR - London HeathrowHence why the BA 767's have MLS hardware installed.Mark

thanks marc.i guess their pilots will get some addition training then... cheers

KILG (Wilmington Deleware) already has a MLS approach with the accompanying approach plate.Cheers :)Woodreau / KMVL

indeed, just looked it up and this is what i got... i don't see an actual difference from an ILS approach, no curved approach or anything...http://ftp.avsim.com/dcforum/User_files/3e44e40512992067.jpg