One for the pilots amongst us.

[Gus Richmond]

Lads,
This morning I caught a flight from Perth to Port Hedland (flight QF1110) early into the flight (about 20 to 30 mins) I was looking out the window to see another jet wizz past in the opposite direction. It was a Thai airways jet of about the same size as the plane I was in (737-800). It went past front to back in say 2 seconds. I could clearly see the windows of the other plane. The plane I was in did a little wigle, it was as if the pilot went to do a right turn but too late the other plane had passed. The other plane apeared to be at a similar altitude (hard to tell as I had nothing relative to judge by) the other plane apeared to banking away in the other direction (again difficult to tell due to how quick it went past). I asked if anyone else saw the plane but got no response, meals being served and headphones were on... So I asked a hostess, she said she would ask a "techie". The hostess came back and said it was ok the planes were 1000 feet apart.
Now I am no expert (which is why I have posed this) but at say 600kph each plane is traveling at (best guess of cruize the speed??) that gives an approach speed of 1200kph, 300 meters apart is way to close???
What is your opinion? Should I raise my concerns with anyone??

Kind regards, Gus.

 

[Jon Briggs]

1000ft is the standard separation between flights these days and has been in the UK and Europe since about 2000. Its called RVSM (Reduced Vertical Separation Minima) and the aircraft and the airspace have to be specially certified to do it. Its quite normal the the little wiggle you felt was probably the pilots saying hello.

 

[Mark]

I find it amazing, that with the whole sky to fly in, we force all the planes to fly in tight little lanes for safety reasons?

 

[Dave Clemo]

Hi Gus, what follows is my opinion. It does not necessarily represent fact or the opinions of my employer, or CASA. I have been a pilot for 12 years, but there are others that are much more qualified to comment than I, and I welcome their input.

Jon is right, RVSM airspace reduces the vertical separation minima quite significantly for flight in Australian airspace above FL290. However, I'm not familiar with anyone "doing a wiggle" to say "Hello". Seems a bit unprofessional with a couple of hundred passengers onboard, and more convenient to just say "Hello" on 121.5 (the frequency we monitor for emergencies and quick "Hello's").

I can't comment on what happened in your instance, having not been there, but perhaps to put your mind at ease:

All jets, and almost all regular public transport aircraft have a system (TCAS) which allows the aircraft to "talk" to each other, and resolve any possible conflicts prior to an aluminium shower. (A euphemism for a mid-air collision)

This system (in it's current guise) only has RA's "Resolution Advisories" (collision avoidance instructions) in the vertical plane, so if the "wiggle" you felt was a change in vertical acceleration, then this may explain it. However a wiggle in the horizontal plane might suggest the pilots visually identified the Thai Airways jet and began to manoeuvre clear.

For either of the two above examples there is a mandatory reporting requirement. Paperwork needs to be submitted to the company safety group, and the ATSB. You mentioned you were flying QF (Qantas)? The safety standard amongst flight crew is held in very high regard within Qantas, with results that speak for themselves. I would be very confident that the crew has reported the incident and it is being investigated.
If I hear or see any reports, I'll repost here if appropriate.

 

[David Morton]

Although discouraged by companies, landing lights were the usual acknowledgement to oncoming but not conflicting traffic. In Africa, the lights were on all the time as were Lateral Nav offsets and a couple of hundred feet from the assigned tracks and levels.

 

[Troy]

Hey Gus, I think you'll find Thai fly A330-300's from Bangkok to Perth. That 7hr flight would be crap in a 737! lol

 

[Scott Calabro]

Perhaps the "wiggle" was wake turbulence.

 

[Mike Drew]

Long-range navigation was a rather rough science before the age of the GPS. Most airplanes relied on INS (inertial navigation system) guidance, which relies on spinning gyroscopes aboard the airplane. Wikipedia goes into excruciating detail on the topic:

Inertial navigation system - Wikipedia, the free encyclopedia

There was a certain amount of drift as time went by during the flight, and it was not uncommon to coast in several miles off course. I can't remember exactly, but I think the max lateral allowable drift was 1.5 nautical miles per hour of flight--so it wasn't a bad thing if you were 10 or 15 miles off course after a ten-hour flight.

Because of this, air traffic control regulations required 2000 feet vertical separation between opposite-direction traffic.

With the advent of GPS, it became possible to establish a position within mere feet, instead of miles. Aviation authorities capitalized upon this greater accuracy and reduced the safety margin accordingly, to 1000 feet of vertical separation.

The bad news about GPS is that the Big Sky Theory is shot to hell. The BST allowed for a degree of safety even when humans made errors; if opposite-direction traffic was accidently co-altitude, the lateral deviation inherent in the INS system would usually allow them to pass alongside one another. Now, if everybody is right on course and somebody screws up their altitude, things can get ugly in a hurry.

In response to this, the ICAO (International Civil Aviation Organization) has instituted what they cleverly call SLOP, for Strategic Lateral Offset Program. The idea is that once aircraft are out of range of ground-based air traffic control radar, they are to offset either one, or two nautical miles right of course. The premise behind this is that even if somebody is travelling in the opposite direction at the same altitude, due to SLOP they will miss each other by a safe margin (i.e. two to four miles).

TCAS is a beautiful thing and has saved my ass more than once. The US Air Force was slow to adopt the technology, and as usual, it required the loss of life before they finally got off their butts and retrofitted their airplanes.

In 1993, a good friend of mine named Pete Vallejo was killed in a head-on collision off the coast of Africa, after his C-141 crashed into a German Air Force TU-154 which was flying at the wrong altitude. (The POS African air traffic controllers failed to order the Germans to climb to the proper altitude, and they failed to notice the need to do so). The airplanes went pretty much beak-to-beak and everybody was killed. Had the airplanes been equipped with TCAS, one would have climbed and the other descended and everybody would have lived happily ever after.

You can read all about that incident here:

C141HEAVEN - All there is to know, and lot's more, about the Lockheed C141 Starlifter!

International aviation is infinitely safer than it once was, but there are still completely barbaric practices in effect in much of the world. Reliance on laughably bad High Frequency radios often leaves airplanes without contact with air traffic control for hours, and we just amble around in the sky, making transmissions in the blind, and if necessary, deviating from course for thunderstorm avoidance etc. and hoping that there's nobody else out there to run into.

It astounds me that with the communications technology that we have now, that in much of the world (overwater and over third-world nations), airplanes are still flying around relying on what amounts to an electronic equivalent of soup cans and string.... :veryangry:

 

[Gus Richmond]

Thanks for the replys lads.
That has put my concerns to rest, although the lack of comms (at times) seems odd.
Kind regards, Gus.

 

[David Morton]

Mike,
You glossed over /past IRS systems which we had in the Boeings that I flew from 86 onwards. They were very accurate and the advent of GPS in the early mid to late 90's only made a slight improvement IMHO. The BIGGEST safety modification in my career was undoubtedly TCAS.
The IRS were so accurate that I narrowly avoided a Varig 767 from Gatwick to Rio
in the scenario you described. Pre TCAS, same FL and opposite direction. he was coming from the north and climbed on VHF about 15 minutes before and we climbed on HF to enter Canaries from the south. He pulled up to avoid us and I looked up and just saw him as he came over the top. Quite a large (sonic?) bang a few seconds prior but
I had no cautions on or any malfunctions and went about monitoring until we 'passed' by. The Co-pilot was in the W/C and rushed out with his trousers around his ankles and the third guy in the bunk slept right through it. The lid was kept on it for a long long time by the Flight Safety department in the company I worked for though Varig did publish the incident in their company magazines. The Canaries controllers were to blame but nothing came of it.

 

[Jon Briggs]

Just a copule of points. The usual way to say hello was a quick flash of the lights. But if your flying one of Frances finest then putting the landing lights out at cruise speed has the same effect on the ride as putting the landing gear down. No faired in lights for us. So a quick wiggle of the wings is a somewhat less intrusive way of acknowledging another aircraft.

I would just say, 121.5 is not the frequency for "hellos". It's a pain having to listen to the rubbish that goes on on that frequency as it is, without having to listen to people trying to say hello to each other.

As for Canaries air space, it's not improved. Topped only by the Greeks, and for some reason the radar controller at Palma, as the worst in Europe.

 

[David Morton]

Speaking of chat frequencies, some used to use 131.8 on the ocean and one particular time a female pilot was making a standard HF position report to Gander and another male voice came up and said "Is that xxxxxxx" and she said "yes" so the male voice said go to 131.8. Everyone and their dogs tuned to 131.8 and when she came on the freq she said ||" xxxxxx here, who's that?" The male voice said (without identifying himself) "XXXXXX, I've seen the doc and he's given me the all clear"
She was a real pain in the proverbial and thought she walked on water.

 

[John Fitzpatrick]

Good one, David. We come up on "Winchester" -- 303.0 Mhz, when we were doing illegal ACT in T-38s during pilot training. Very immature "Hey Rube!" and "Rat-a-tat-tat", mostly.
Back then we had no separation regs, and T-38s climbed and descended to base on the same TACAN radials. The "Big Sky" mentality prevailed at the time ('69).