On The Airbands

What exactly had Alan overheard? Was it a FleetSatCom downlink? No. . . they start at 261. 450 MHz. Close. . . but not quite correct.

Alan stated he believed the station was “Las Vegas Centre” from continental USA, an opinion you cannot fail to support after hearing the station yourself. And that is precisely what I did do from my home in Sydney. After monitoring the signals at 0132 Zulu continuing on for some fifteen minutes before they disappeared, I listened to a cassette recording Alan had made of his intercept on the frequency.

The clearest monitored intercepts were on Alan’s tape, and proved to be Las Vegas Centre advising an aircraft to “call Los Angeles Centre now. . . ” and another occasion where the controller at Las Vegas was conversing with a pilot on the subject of the “100 million dollar Lotto”.

The controller appeared to be more interested in the Lotto than he was in controlling his aircraft. Alan’s monitoring of the station was effected between 0130 and 0400 Zulu.

But how did it happen? Everyone knows you can’t listen direct to US VHF or UHF aviation frequencies! A VHF or UHF frequency for Las Vegas Centre (Control) had possibly inadvertently scored a ride through a US military satellite, a satellite it was never meant to uplink into. Cable leaks or intermodulation problems near the satellite uplink equipment in the US may have opened the door to the AM air frequency. Normally the satellites accept NFM signals, but the air frequency passed into the system without impedance, and was clearly audible here.

You never really know what you’re going to hear next “On the Airbands”!

One of my spies at Sydney Airport ATC, code name “Walter”. advises that some months back Sydney Tower and Auckland Approach found themselves hearing each other, and were able to talk to each other as well on their common frequency of 120. 5 MHz!

Not only were they able to exchange “giddays”, so were all the aircraft they were working on the frequency! Everyone seemed to be a totally readable strength five signal, on both sides of the Tasman Sea.

What caused this one? Surely no satellite was involved here? You’re right. . . the Sydney/Auckland Tasman connection delighted monitors in both countries courtesy of a quaint and reasonably rare phenomenon known as “temperature inversion”. I’m assured by those more learned than I that under these conditions communications are possible on VHF or UHF over thousands of nautical miles, thus the fairly easy 1,200 nautical mile span on this particular day

I’m told by “Walter” that it was pretty confusing for all con cerned until controllers sorted out some semblance of order on the frequency. Wow! Just think. . . “Err. . . Qantas 43, this is Syd- ney Tower and Auckland Approach. . . you’re clear for takeoff!”

And Auckland could have provided the latest TAF (terminal area forecast) on Auckland Mangere Airport in voice mode to aircraft still on the ramp in Sydney!

A thank you to Steve Hudson from Salisbury, SA for writing in like so many other readers did with information regarding the “Hudson” RAAF callsigns. “Hudson” is the rootword used by HS. 748 aircraft deploying from the East Sale RAAF Base. And Steve Hudson is quite taken with the way his namesake is used as a military callsign by 32 Squadron!

Steve tells me he spent much of his 1990 monitoring time listening to 17904 on the CWP (Central West Pacific) HF frequencies, hearing lots of Continental, Qantas and also military traffic. I have often been asked if I can supply the frequencies used by the Roulettes for air/air communications to coordinate their air show display routines. Yes, I now have them, but I’m reluctant to print them in case the team decide to change them immediately after they are published. Anyone interested drop me a line with a stamped self addressed envelope. Owing to the extremely high volume of mail this column has attracted, I cannot now reply to any mail that does not include the return postage.

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76 Squadron RAAF, additional callsign rootwords for the MB-326s (Macchis) are “Phantom” and “Devil”, the latter I’m told being an MB-326 formation. The other already published callsign is “Fairway”, and the formation callsigns for that rootword are “Panther, Cougar, Cheetah, Leopard, Lynx, and Tiger”.

The callsign “Rescue 161″ is either a C-130 or P-3C Orion aircraft from the RAAF involved in SAR or other emergency operations. Any aircraft operated by Police agencies where the aircraft is on a mission relating to the threatening of human life is frequently callsigned ”AirPol”.

“Spider, Redback and Cobweb” are Lears operating out of Nowra NAS for the RAAF, RAN and Army involved primarily in towing aerial targets. The company operating these aircraft on contract is Fleet Support. “Cobweb” may also be used when the aircraft are being flown in support of Army firing practice missions, and the root word “Baldock” is used for Naval gunnery and detection exercises.

Additional callsigns forAustralian Army aircraft are “Pegasus” (5Avn Regt), “Destrier”(A Sqdn), and “Warhorse” used by B Sqdn. Scott Lindsay of Warrington Downs, NSW writes and refers to “On the Airbands” November 1 9 90 edition, which featured ”Aircraft Enhancement of Radio Signals”. I’ll let Scott take up the story: “I have a situation you might like to hear about. Just after some severe storm activity in my area, which was heading easterly, Sydney controllers closed the airport to all aircraft except those within a five nautical miles radius.

“Tuning in to 123. 4 ArrivaJs frequency, I monitored a flurry of activity as the controller dished out the holding instructions to numerous aircraft. One aeroplane I particularly decided to track was an Australian 727 which shortly after was handed off to Approach. After the monologue of transmissions to the controller, I concluded the airliner would be doing two-minute left hand patterns above and around my house. Sure enough . . . thirty seconds later, through the binoculars, there was the 727 at about 3,000 feet, periodically entering and leaving cloud.

“I then ran inside, remembered your ‘Enhancement’ article, then also recalled my great problems receiving signals from Bankstown ATIS on 120. 9 and Sydney Approach on 126. 1. I dialled in the two frequencies, and yes . . . you’re right . . . there they were, unlike ever before, loud and clear, strength five signals! A guaranteed thirty minutes of pure reception was coming my way courtesy of the accommodating under fuselage of the Australian Airlines 727 reflecting the signals to my antenna system! Thanks Australian Airlines . . . and thank you Bob!”

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Kel Shaw of Mt Isa, Old listens to aircraft on a VHF Sony Air 7 receiver and an old “frog” (FRG-7700) HF receiver for traffic further afield. He recently monitored New York for the first time on frequency 113 96 kHz. The piece he sends us is from the day the Gulf War officially ended. Frequency: 125. 2 Brisbane Control, Ansett BAe 146 VH-JJY.

VH-JJY : ”Arr, Brisbane Control, Juliett Juliett Yankee, would you be able to give us coordinates for Kuwait, and heading, from our present position please?”

BRIS CTL: “Err, Juliett Juliett Yankee, standby. ” {This was a lady controller, and a cool one too!)

A short time later . . .

BRIS CTL: “Juliett Juliett Yankee, Brisbane Control, your Kuwait co-ordinates are. . . (rattling off a set of numbers too fast for Kel to write down).

Then came stunned silence, followed by. . .

VH-JJY: “Err, Control, Juliett Juliett Yankee, gee. . . thanks, err, if we divert now from ENTEC, we could be thereby err . . . tomorrow this time! It’s only 7,000 nautical miles!”

Not to be outdone. . .

BRIS CTL: “Juliett Juliett Yankee, call Control on 123 decimal zero, then send me a postcard from the Gulf. See ya! (giggling)

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Noreen Stevenson from Forbes, NSW has monitored gliding operations from nearby Narromine on 122. 5 MHz. She asks if I can supply frequencies and stations worked by the Sydney/ Harare Qantas service (QF23, a 747-438).

The aircraft uses VHF Sydney/Perth, then the INO-1 frequency family from Perth to Harare, across the Indian Ocean. Frequencies are 3476, 5634, 887 9, 13306 and 17061. Stations worked are Perth, Cocos and Mauritius, and when in VHF range of Harare the aircraft calls the Airport on its VHF 125. 1, as Harare

has no HF facilities. . . ‘

Flight time for the sectors, depending on headwinds is 4 hours 50 to Perth ex-Sydney, and 11 hours 15 Perth/Harare.

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Well that wraps it up for this month. We’ve certainly jampacked the information in for you. Hope you find it useful and interesting. Write to me with contributions and send a stamped self addressed envelope for a reply. Bob Bell, PO Box 301, Chester Hill, NSW 2162. Good monitoring, see you next time.