Sydney Airport passes the buck

Photograph of jet aircraft approaching Sydney Airport

Sydney Airport has responded to my email about interference with our Wi-Fi and Next G reception. In standard corporate style, they begin by reminding me that “aviation safety — both in the air and on the ground — is paramount”. It gives some useful information — but passes the buck firmly to Airservices Australia.

The full text is over the jump.

Yes, the email arrived a day later than their 3-day stated turnaround time, but that’s OK considering I did say this would all be published.

Airservices Australia runs stuff like air traffic control so, yes, this does perhaps belong in their court. As they’ve been suffering some problems themselves, it’ll be interesting to see their response.

Here’s the full email from Sydney Airport:

Dear Sir,

Thank you for your recent email concerning the electronic interference caused by air navigation equipment at (and in the vicinity of) Sydney Airport.

Aviation safety — both in the air and on the ground — is paramount. The Australian Government agency responsible for providing safe air traffic control management, telecommunications and navigation services to the aviation industry is Airservices Australia. Airservices Australia therefore operates a number of radio navigation aids that provide guidance to aircraft operating in and out of Sydney Airport, particularly in poor weather conditions. It also operates a number of surveillance systems for aircraft in the air around Sydney Airport (and beyond). More specifically, its website indicates that the following systems are provided:

  • Ground-based communication systems — operational and corporate voice and data Networks, ISDN, Ethernet, voice switching systems, Aeronautical Telecommunications Network and communication towers and masts
  • Navigation systems — Instrument Landing Systems (including localiser, glide path, markers and locators) and navigation aids (including VHF Omni–Range and Distance Measuring Equipment)
  • Surveillance systems — Radars — primary / secondary, surface movement, parallel approach and non-radar Automatic Dependant Surveillance-Broadcast

As you point out, aircraft themselves also carry on-board sophisticated navigation and other equipment.

As to the impact these systems have on electronic equipment located outside the airport, given the above, I would recommend you contact Airservices Australia. They would have experts available who should be able to provide you with more precise information concerning why a particular piece of air navigation or related equipment may be interfering with other ground-based equipment at certain frequencies. To contact the Noise Enquiry Service, please phone 1800 802 584 (freecall) or 1300 302 240 (local call).

You have also mentioned the work being undertaken on Sydney Airport’s cross (east-west) runway. This relates to the Runway Safety Enhancement Project. As you correctly point out, the work needs to be done – this is because it is necessary to comply with Australian and international aviation safety requirements.

Further information concerning this project can be found at: As you have noticed (living in Enmore), the restrictions on the operation of the east-west runway while construction is underway has temporarily changed the distribution of aircraft noise around the airport. The main impact on use of the east-west runway occurs during the first phase of the project, which is due to be completed by mid-June 2009 (having commenced in mid-October 2008).

Information published by Airservices Australia shows that the proportion of aircraft movements to the north of Sydney Airport during November 2008 (the most recent data available) was 31.9%. This is actually less than in November 2007 when movements to the north of Sydney Airport accounted for 34.01% of all movements. It should also be noted that not all of those aircraft movements would have been directly over Enmore. This is because Enmore is less affected by aircraft departing from the main north-south runway than it is by aircraft approaching the north-south runway (aircraft departing from that runway turn to the north-west soon after take-off as they track towards Richmond or Katoomba). Airservices Australia should be making the December 2008 data available in the next few weeks.

Sydney Airport apologises to people who will be affected by this vital runway safety project, but it is essential that we comply with the Australian Government’s air safety regulations.

Ted Plummer
Manager – Major Projects Consultation and Communications
Sydney Airport Corporation Limited

[contact details redacted]

I’m always amused that large organisations just can’t avoid adding the boilerplate mission-statement stuff into every piece of communication.

The fine-grained statistics on which aircraft flew where will depend, of course, on the weather. The weather in December 2008 was very different from 2007. As, for that matter, was the health of commercial passenger aviation.

At least Sydney Airport apologises for the noise and interference — but I don’t see any offer of that make-good slab of beer, or a tour of the new facilities when it’s finished. That’s a shame.

Next stop: Airservices Australia. Stay tuned.

8 Replies to “Sydney Airport passes the buck”

  1. More specifically, its website indicates

    As in, we have no idea ourselves what services they provide, we had to check their website to find out?

    (Where is your “preview” option for comments? Where is your “Follow comments via email” button? subscribe-to-comments plugin is your friend!)

  2. @James Polley: Comment-preview and “Comments feed for this article” are working just fine for me. Firefox version whatever-is-currently-shiny-bright on OS X. Don’t get snarky, do a proper, professional fault report. 😛

    1. “More specifically, its website indicates

      As in, we have no idea ourselves what services they provide, we had to check their website to find out?”

      We-e-e-ll, in their defence, it could be interpreted as “you could have looked this up yourself, but here it is in case you don’t believe us.”

      1. @Snif: There is indeed an argument which says I should be aware that Airservices Australia runs the airside stuff while Sydney Airport runs the groundside.

        That argument becomes stronger when I reveal that for two years I actually worked for what was then the Department of Transport / Transport Australia / Department of Aviation. One year was even in the Engineering Branch — the specific branch which installed and maintained all the electronic gadgetry of which I complain.

        (The other year was in Staff Development, where I learnt a lot about people and organisations.)

        Nevertheless, as a punter… I mean, as a general member of the public, it’s not my job to keep track of the various nefarious corporate connections between the nefarious various bits of the privatised aviation industry. My problem is connected with “the airport”, so I approach “the airport”.

        1. Then this response seems entirely adequate, yes?


          You see that aircraft transmit in the 5-25 watt range on these frequencies, roughly speaking:

          Voice comms: ~120MHz
          DME, ACAS: ~1.1GHz
          Radio Altimeter: ~4.3GHz
          Weather Radar: ~5.4GHz, ~9.4GHz
          Doppler Radar: ~8.8GHz, ~13.3GHz

          Now, using the database at:

          We can see what the airport itself is doing.

          Transmit power is specified as the pX (peak), pY (mean) or pZ (carrier) power in watts, depending on the nature/modulation of the signal being broadcast.

          Some examples:

          Designator – Freq – Description – Transmit Power
          7M00F9W – 10.565GHz – MSB Lead Light Runway 34l SYDNEY AIRPORT – 0.4pY
          18K5A9A – 332.0MHz – Glidepath/DME Runway 34R SYDNEY AIRPORT – 5pX
          18K5A9A – 330.8MHz – Localiser Runway 16L SYDNEY AIRPORT – 5pX
          12K5A9A – 110.9MHz – Localiser Runway 16L SYDNEY AIRPORT – 15pX
          12K5A9A – 109.5MHz – Localiser Runway 16R SYDNEY AIRPORT – 25pZ
          500KP0N – 991.0MHz – Dmei Runway 34 Right SYDNEY AIRPORT – 150pZ
          500KP0N – 1.007GHz – Glidepath/DME Runway 16L SYDNEY AIRPORT – 150pZ
          14M0P0N – 2.767GHz – Sydney Terminal Approach Radar SYDNEY AIRPORT – 600,000pX

          As you can see, the approach radar is on 2.767GHz, and transmitting at 600,000 watts. Considering your 2.4GHz gear is probably dissipating 30-100mW into its antenna, that’s one hell of a noise source.

          It’s been years since I was savvy with this stuff, but if I recall correctly, the law is written such that emergency and infrastructure broadcast licenses will always stomp all over users of unlicensed bands wherever deemed necessary.

          It’s a fact of life. The unlicensed bands are there for convenience for citizens to enjoy wherever possible, but in this imperfect world, a noise free 2.4GHz band is not a right that you have.

          So, you’re screwed for 2.4GHz. Possible solutions: use a different unlicensed band or go the Telstra NextG route (850MHz). Unfortunately, this is close the Glideslope frequency of 1007MHz (for 16L), and is transmitting at 150 Watts, not to be sneezed at.

          As Telstra actually paid for a broadcast license, they have some rights that a lowly citizen on the unlicensed bands do not, and may be interested in sorting out the interference problem with you and ASA. Or not.

          The buck ultimately lies between you and Telstra, as far as I can tell.

          I’m really not sure at all what you expect Air Services to do for you.

          1. I meant to elaborate. At a guess, it could be the GS on 1.007GHz that’s giving you grief. Even though it’s not at 2.4GHz, considering it’s a hefty 150 watts output, if you were close enough in proximity (and polarisation, lay of the land etc. all conspires against you) it may be close enough to the frequency of an IF (intermediate frequency) stage or harmonic thereof used in your WLAN gear’s radio circuitry to cause these problems.

            In other words, your cheap wireless gear just isn’t able to cope with the outside noise it’s supposed to.

            Now, back to job hunting. I was a Systems Engineer myself, actually, but not entirely a software/IT one 🙂

  3. @csirac2: Thank you for the detailed explanation! A friend who also knows about aviation communications and navigation aids (RAAF background) has speculated about various interference sources, but you seem to have identified the most likely culprits.

    I guess that’s all I expected Airservices Australia to do too — though hey, they can always come and re-work my WLAN. 😉

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