2 x A330s within 700ft at38,000 FT..............!..

[Guest Maj Millard]

And they worry about our paperwork not being in order ....!!!.........someone dropped the ball here big time ....................Maj...

 

 

[dazza 38]

True but 700 feet to me is a fair distance. 7 feet on the other hand would be close.

 

 

[Guest Maj Millard]

Dazza, 700 FT at that speed head-on, is not in anyway safe, and below required separation minimums...apparently an avoidance manoeuvre was carried out, so it may well have been 7 Ft !.......Maj...

 

 

[Marty_d]

True but 700 feet to me is a fair distance. 7 feet on the other hand would be close.

Not when your wingspan is almost 200 feet, you're probably doing around 0.8 mach and 200+ oblivious passengers behind you are depending on you to maintain separation...

 

 

[old man emu]

I see that they stood down the ATC guy who authorised one of the aircraft to change altitude.

 

I heard a sound grab from a passenger in one of the planes who said he say the other plane descending to the left. Seems the pilots were on the ball at the time so they carried out the correct avoidance procedure.

 

OME

 

 

[ben87r]

Wouldn't exactly call it "mid-air catastrophe was averted when a traffic collision-avoidance " but a case of the system doing its job, separation of 1000' isn't much either when you think about size and speed. ATC DO make mistakes like anyone else so it's up to us and in this case aircraft systems to still be alert as to the situation

 

 

[dazza 38]

They have TCAS, so I think it is a storm in a tea cup.

 

 

[Downunder]

I think the point is that the flight management systems should not get to a point where "avoidance" is required.If this becomes the norm then one daythat too will fail and they will hit.

 

jumping up and down over a near miss is preferable to jumping up and down over a collision.

 

The last resort systems in place should never become the standard avoidance system.

 

An invesigation is fully justified I think.

 

 

[facthunter]

It's not a storm in a tea cup. Separation standards were breached. The system should have picked that up. TCAS works when the system failed as it did. From memory I can only recall a couple of similar instances on transcontinental routes in Australia. We should have better procedures than yesteryear, so it must be investigated. (The same as the low fuel situation). AVMET never have accepted any responsibility for the absolute accuracy of a forecast, but procedures can always handle a good re-examination.

 

With the accuracy of todays navigation GNSS there is more chance than ever of a head on. Planes are all virtually on track and on height. IF the clearance is in error collision is likely as the near miss is almost eliminated as a possibility .Nev

 

 

[Guest Maj Millard]

All a pilot has to do is sit there for a few seconds wondering if the alert is real, should I take evasive action.?...... Mmmmmmm.....what do you think Jack, should we request a height change from centre ?......WHAM !!!!....................sorry too late !......................

 

 

[facthunter]

I haven't used TCAS but with GPWS (Ground proximity warning ) you act on it. You may leave an assigned level in an emergency situation. You manoeuver to avoid risk Ie OFF TRACK descent and ADVISE what you have done.. Fits the Aviate Navigate Communicate thing. Two jets head on are closing faster than a bullet .Nev

 

 

[ben87r]

An "aviation expert" said on sunrise that in the last 10 years that this type of occurrence had happened 52 times. Not sure if its correct. I agree that a full investigation is warranted but the media hype is what is a load of ----

 

 

[Bubbleboy]

Ironically I watched this very situation on Air crash investigations the other night. Unfortunately the Pilots followed ATC directions instead of the TCAS and whammo! The outcome of it all was that the pilots are supposed to follow the TCAS directions and not ATC.

 

ATC are humans and mistakes will always happen. We cant stop that. Glad all turned out ok in this case.

 

Scotty

 

 

[Cosmick]

Ironically I watched this very situation on Air crash investigations the other night. Unfortunately the Pilots followed ATC directions instead of the TCAS and whammo! The outcome of it all was that the pilots are supposed to follow the TCAS directions and not ATC.ATC are humans and mistakes will always happen. We cant stop that. Glad all turned out ok in this case.

 

Scotty

Yeah saw that show, the TCAS told one to decrease height and the other to climb, if they followed directions of the TCAS collision would have been averted but they both dived into each others path.

 

http://en.wikipedia.org/wiki/%C3%9Cberlingen_mid-air_collision

 

 

[dutchroll]

This incident is my current aircraft type and my company you're talking about. It was certainly not a storm in a teacup and is not being seen that way by anybody internally I can assure you.

 

GPS navigation is a wonderful thing, but with these navigation systems which can now stick opposite direction aircraft on the same tracks with accuracy tolerances in metres, plus the advent of RVSM cruising levels, a whole new can of worms with air traffic separation has been opened. TCAS here saved the day, though the safety investigation hasn't yet been completed. You have to understand that 700ft vertical separation and reducing is not a lot in a big jet closing on another at around 1500 km/h given the inertia, time, and space required to change its vertical direction.

 

The A330 TCAS 2 system here issues a co-ordinated resolution advisory (RA) to both aircraft at approximately 25 seconds from the computed collision/impact. The pilots are allowed 5 seconds to disconnect the autopilot, turn off the flight directors, and change the vertical speed to get into the green band as smoothly as possible (though it takes only a small attitude change for a large vertical speed change when you're doing 450 knots).

 

If the TCAS RA is reversed or strengthened (e.g., maybe one aircraft has been slow to follow the RA and the computed collision point now changes for the worse), the pilots are allowed 2.5 seconds to get the vertical speed into the new green band.

 

We (and some other airlines) fly 2nm track offsets when in certain countries' airspace because the navigation systems are so accurate, if ATC screws up you will be put on an exact head-on collision course with opposite direction traffic. TCAS 2 is a wonderful system when used correctly and trained properly and I have no doubt it probably saved the day here, as it has on previous occasions. It could easily have gotten mighty ugly.

 

 

[Jabiru Phil]

Well, if we get back to our recreational flying activities, the above has no bearing on our normal procedures, it has been suggested in previous posts that it it advise able to track to the RIGHT of track by a mile or so.

 

I have taken this info on board on X country flights. Instead of firing up the destination before take-off I have now Got into the habit of crossing the direct line to the waypoint to the right and then rebooting the GPS to the waypoint.

 

If for instance you take a direct line from A to B from your departure point and the other aircraft does the same with his, there will be some excitement if not following the 1000' seperation.

 

Only takes both aircraft to be 150' below their altitude to be separated by the 700 ' as stated.

 

IMHO

 

 

[Patrick Normoyle]

Phil, this is very similar to what I do, I'll often plan a trip via an enroute position that I "presume" is off the beaten track. When I came to Loxton for your wonderful event some months back, I did this. It wasn't that necessary as I was on my own for the trip there, but I was one of about 10 aircraft all departing for Murray Bridge, Strathalbyn or Aldinga, all within minutes of each other, this is when I think it pays to be off the nominal track by a portion.

 

Looking forward to the next Loxton flyin.

 

 

[Jabiru Phil]

Patrick,

 

We have been nurturing your grassy spot for you. Date has been set I believe.

 

Phil.

 

 

[Patrick Normoyle]

Looking forward to it, hopefully I'll have the wife and kids with me.

 

 

[dutchroll]

I guess one thing I didn't add above in relation to this incident is that maybe, speaking of small aircraft & recreational aircraft, it's good to think about transponder issues. I know they cost money, but a good transponder is a good thing.

 

The transponder is one item I refused to compromise on when getting my "hobby" plane built. I went the full modern brand name, reputable, Mode S, higher power transponder (there is no weight or size penalty - just a bank balance penalty) with extended squitter in case I later go nuts and add an ADSB box. I want not only other small aircraft which may have traffic awareness displays hooked up to their transponders to see me, but I know first-hand how hard it is for the bigger boys to spot small planes when they're coming and going from those larger airports, so if I'm in the vicinity OCTA under their flight paths I want them and ATC to know that I'm around!

 

 

[Camel]

I guess one thing I didn't add above in relation to this incident is that maybe, speaking of small aircraft & recreational aircraft, it's good to think about transponder issues. I know they cost money, but a good transponder is a good thing.The transponder is one item I refused to compromise on when getting my "hobby" plane built. I went the full modern brand name, reputable, Mode S, higher power transponder (there is no weight or size penalty - just a bank balance penalty) with extended squitter in case I later go nuts and add an ADSB box. I want not only other small aircraft which may have traffic awareness displays hooked up to their transponders to see me, but I know first-hand how hard it is for the bigger boys to spot small planes when they're coming and going from those larger airports, so if I'm in the vicinity OCTA under their flight paths I want them and ATC to know that I'm around!

I would be interested in the transponders that you recomend I have always had a transponder for this reason but I have no mode S.

 

 

[dutchroll]

I would be interested in the transponders that you recomend I have always had a transponder for this reason but I have no mode S.

I put in the Trig TT22 Mode S transponder (Trig Avionics, UK). By all accounts it has a good reputation. It's also very lightweight, remotely mounted, and has a neat little control head. The TT21 is a lower-power (Class 2 as opposed to Class 1) and slightly cheaper brother to it but the price difference isn't huge so many people seem to be just throwing in the TT22.

Both are capable of ADSB in/out if and when you (or CASA) decide you want it.

 

 

[Downunder]

Dynon also use the 21/22. I'll be fitting a tt22 to my skyview soon.

 

 

[Gnarly Gnu]

Any radiation issues with having these transponders in close proximity in a composite or fabric aircraft? (Not to promote thread drift but I've always wondered).

 

 

[facthunter]

I believe there are , but I will leave it to people more knowledgeable than me in this area to get into the specifics. Nev