WAM failure
 

Kaz, I have added this to Dick's thread on Melbourne controllers doing the impossible at Hobart due to its similarity to the equipment Dick wants used at Hobart.

LET'S GET SOME TERMINOLOGY SORTED
 

Multilateration (MLat) has several uses. One of them is for wide area surveillance and is then called WAM. Another is for surface surveillance where it provides high integrity and accurate data to an ASMGCS. Yet another is where it forms part of the Precision Runway Monitor (PRM) system. It also has other uses but most of you do not have sufficient clearance to be told.

In this case the PRM system seem to have a problem. Is it the surveillance data input or something else? The ABC (not a noted surveillance expert organisation) seems to think it is the MLat.

The temporal situation is interesting. i am reminded of my time as the SR (ATS) Manager in AsA of a similar problem with (as I remember - few years ago for an old fogie like me to accurately remember the details) a frequency, or was it surveillance or a NAVAID. We traced it down to a plastic welding operation near Port Botany. Funny thing about frequencies.

Not even suggesting this might be the case but another issue with a frequency in Melbourne was traced by those engineering experts in David Gale's group to a curtain near a VHS recorder in a house near by.

Just saying.

MJG
Old fuddy duddy ex military guy with only a passing interest who still wonders why the report on Risk Implication for Surveillance in Airspace is still locked away in OAR.

I seem to remember it was the approach freq of the time. The interference was eventually traced to - you are correct - a plastics welding factory in Redfern of all places, using a 'new-fangled high freq. plastic welding machine'.....

I was one of those 'OMC' guys at the time in SY AACC, as well as other 'duties'....

I can't recall what the solution was, whether it was a freq change or a suggested mod to the Redfern factory equipment - I suspect the latter.

Cheers