On the Airbands

Sydney Tower

“No Sir, I believe it was the Easter Bunny!” (said with great sincerity).

Another Sydney-ite, Michael Hore from Sydenham, provides this story about one week after KSA’s east/west RW07/25 was put back into service at the direction of the new transport minister. From the details displayed in this story, it appears some pilots may need to refamiliarise themselves with it …. VH-HYA (Ansett A320) had been vectored to final on RW07. We’ll take up the story from there:

Sydney Director

“Hotel-Yankee-Alpha, Sydney Director, report for me when you have the runway in sight.” VH-HYA: “Hotel-Yankee-Alpha, roger that, ahh … but we’re just not too sure what it looks like!”

Sydney Director

“Oh … just like any other runway really.”

It seems like Easter time was a good time for monitoring aircraft, with this story from about 530nm to the north, at Brisbane Airport, on Approach frequency 124.7 MHz. David Voss from Bracken Ridge was monitoring on his Uniden Bearcat BC100XLT. The “star”, VH-EWA, is an Ansett Fokker F28-4000 Fellowship.

Tower

“Echo-Whiskey-Alpha, radar shows you drifting six miles to the left of Kilcoy Marker!” VH-EWA: “Yes, you’re right … we are six miles west of Kilcoy. There’s lots of wind up here in the Omegas.”

Unknown

“Excuses … excuses!”

Ball Corporation supplies airlines with, amongst other products, mobile satellite communications systems. In one of the “ads” the company has taken out in various worldwide industry publications, Ball Corporation seems to be trying to convince the airlines that there is someone out there listening! Can you believe that? I wonder who’d be involved in that pursuit? The ad starts off …. “Is Someone Listening? Protect your vital communications with secure satcom systems from Ball.” It got me thinking. Although all the voice channels in the VHF aviation band, and most in the military UHF allocations are broadcast in clear unencrypted speech, how close is the dreaded “digital voice communications” mooted for so long by the airlines and ATC authorities? For the answer, I went to the man who is closest to the horse’s mouth, Bruce Ames, of Sunnyvale in California USA. Bruce writes the “Aircraft” column for the Radio Communications Monitoring Association scanner journal in the United States. Bruce tells me that a senior airline friend of his has disclosed that his airline has returned a request for proposal to the United States Federal Aviation Administration (FAA), dealing with “VOCODING”. This stands for “voice coding”, and means that the VHF frequencies we copy ATC and aircraft on now would be digitised, and we would hear zilch! Bruce Ames goes on to say that “there will be a long phase in schedule before all airliners in the world are expected to comply with the new digital modulation scheme”. The FAA is co-operating with the International Civil Aviation Organisation (ICAO) and its Aeronautical Mobile Panel in the solicitation of Vocoder manufacturers to evaluate the current technology that’s available and relate it to air traffic communications. Once decided upon, the Vocoder standard would be used both locally and internationally. International usage would be via SatComs, primarily, and HF for backup communications only. This would preclude us listening to any voice communications, and we would be left with digital ACARS transmissions only to monitor. While speaking with Bruce Ames, he made me laugh by getting on to his hobby horse, the traffic delays at San Francisco International Airport. Bruce states that at San Francisco, there is a “RULE-OF-THREE” applying. He believes that anything that adds up to three at San Francisco Airport will cause a delay. As in …. 1. Three planes in SFO airspace at one time. 2. Two planes and one cloud. 3. One airplane, one cloud, and one car on Freeway 101. Bruce is convinced that the way the FAA picks airport locations is totally screwed up. He observes that when the fog rolls in at SFO, it rolls in ONLY over the airfield. North and South of the field is frequently totally clear while the airport is enshrouded in thick fog! Sounds like Badgery’s Creek (the ‘possible’ location for Sydney’s new international airport) was picked by the same guys! Badgery’s is fog bound for about one third of the year in the early mornings, which is of course when the big jets are mostly arriving. Arloa Popke and Daniel Cole, friends and correspondents from British Columbia in Canada, tell me that they were monitoring Vancouver International Airport Tower frequency 124.4 MHz and were actually watching the flight from the observation area when “Canadian 17”, a DC-10, aborted its takeoff. The DC-10-30 was hurtling down Vancouver’s main runway at 167 knots when the Captain, Jack Tucker, heard a loud thudding sound and elected not to rotate. If the fully fuelled aircraft had been any further down the runway, and travelling any faster, it would have been committed to takeoff. Tucker would have been forced to get the airplane airborne with only two of the three engines working, as No 1, the left wing engine had totally lost power at the time the Captain heard the bang. The aeroplane sped down the runway, to Arloa and Dan’s horror, with only one of its three thrust reversers working, and flame coming from the rear of No 1 engine. The tail mounted engine (No 2) thrust reverser had not been working prior to flight, but under rules which allows DC-10s to fly with the tail reverser unserviceable, there was now only one thrust reverser left, No 3! Murphy’s Law working I guess. The widebody jet had been bound for Taipei, but it didn’t quite make it there. When it finally came to rest the DC-10 was 50 metres off the runway and just two hundred metres short of going for a swim in Georgia Strait Bay. Even when it ground to a complete stop, the crew’s problems were not destined to end! The airliner had hit muddy ground, and the nose gear wheel strut collapsed. As we examine the situation, in reality, poor Captain Tucker had actually done a magnificent job. He and his crew managed to safely stop the aeroplane, and they somehow managed to miss some centreline runway lights on the way there. If they had struck them, those lights could have sparked and caused the fully fuelled airliner to explode and burn. The final toll: no one fatally injured, but seven were admitted to a nearby hospital, most being injured on the evacuation slides. One airport worker, Earl Sanderson, was treated for shock. He had been operating an airport grader at the end of the runway, and saw the giant DC-10 aircraft looming up on him. The airliner narrowly missed him! Eventually, after an entire weekend of discussions between aeronautical engineers discussing how to move the stuck-fast DC-10, “Canadian 17” was eventually cleared away utilising three giant cranes.

New frequencies at Sydney International Airport have been in use for a while now, and several people have written asking me to discuss them. First up, Flight Service Officer Craig Simmons from Kogarah in Sydney NSW, which is right near the airport, wrote to me to say that 135.25 MHz is the new Sydney Flight Service frequency replacing 125.0 MHz. Mt Canobolas near Orange is where the frequencies are located. Canobolas is also the new home to broadcast station Triple J. Through signal intermodulation, the radio station was creating massive interference to Sydney FIS frequency 125.0 MHz, so instead of getting Triple J to move, in its inimitable fashion, AirServices Australia changed frequency to 135.25 MHz, also run from Sydney Flight Service Station. The new frequency does not suffer the intermodulation problem that the old frequency was experiencing. Due to the commanding view that the new Sydney Airport Tower has, the old International Apron Surface Movement Tower located on top of the International terminal Y-shaped aerobridge hallway in front of Terminal A is virtually not needed. The new Tower has added another Surface Movement Control (Ground) frequency to the existing 121.7, and deleted the International Terminal Apron SMC channel of 86 Australian Aviation July 1996 122.3 MHz. The new SMC channel is 126.5 MHz. The ATIS computerised broadcast has changed from the old 133.85 to 127.6, which is difficult to copy in most areas of Sydney unlike the 133 MHz channel’s clear crisp signal all over Sydney. That’s progress I guess! For a couple of weeks, a new Approach frequency (118.4) was used instead of the Southern/Western Approach channel of 128.3 MHz. Now, 118.4 has itself been passed into Approach History, by being dropped, and 128.3 has been returned to use. And last, but by no means least, all control frequencies Australia wide are now referred to as “CENTER”. Yep, they’ve elected for the American spelling … center, not centre. Examples are: Melbourne Center on 133.5, Brisbane Center on 128.6, and Sydney Center on 123.4 MHz. (I wonder if President Clinton will start campaigning for re-election downunder now?)

John Wylie contributed this story. It concerns Adelaide Approach, VH-RMA, and Parafield Tower. The aircraft involved, VH-RMA, is a Boeing 767-200. The frequency the aircraft was monitored on was 118.7 MHz. VH-RMA: “Adelaide Approach, Romeo-Mike-Alpha descending to seven thousand, received LIMA” (referring to the ATIS broadcast being received okay).

Parafield Twr

“Romeo-Mike-Alpha, P-A-R-A-F-I-E-L-D T-O-W-E-R, say aircraft type please!” VH-RMA: “Ehh … AIRCRAFT type … err … (ha ha) … did you say you’re Parafield Tower?”

Parafield Twr

“Affirmative, Parafield Tower Sir.”

Unknown

(mild expletive). VH-RMA: (second voice) “Sorry mate, I guess we dialled the wrong phone number!” The correct phone number should have been Adelaide Approach/Departures frequency of 118.2 MHz. A slip of the finger caused a slip of the tongue by VH-RMA, and no doubt more than a slight twitch of embarrassment on the face of he-who-tuned-the-VHF-comms set! Better luck next time guys!

Finally this issue, answers to Daniel Boyce’s questions: What are the frequency presets for Williamtown STUD 4 and STUD 5? STUD 4 = 261.4 – Approach (UHF military frequency) STUD 5 = 254.7 – Traffic (UHF military frequency) The RAAF categorises its regularly used frequencies into set channel positions in their comms ‘boxes’, which they term ‘studs’. A stud = a family. In this case, a family of frequencies. The use of STUDS makes it easier and quicker to pass frequency information over the radio, and reduces manual tuning errors. STUDS also supply a very limited degree of communications security for the RAAF.

As you’re reading this article, this writer is again winging his way to the United States. But this time, it’s not to attend a communications convention. I’m performing a “security function” at the Atlanta Olympic Games, and hope to do some quality aviation monitoring in between my shifts. Tell you more on my return in August, so until next month, enjoy your monitoring, and if you hear a funny or unusual story on air, drop me a line. Also, remember to write for my latest book, Climb into the Cockpit by Radio, at $22.95, including postage. Bankcard, Mastercard, and Visacard are welcome. Or send a cheque. You’ll be truly thrilled to look over the huge database we’ve put together in this book for your information. Write to Bob Bell, Airband Communications, PO Box 16 Georges Hall 2198. Phone enquiries welcome on 015 897332