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Old 22nd Oct 2004, 16:53   #1 (permalink)
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Times article on near miss in Dec 2003

See Radar flaw sent planes just 600ft from disaster. The two 777s were in the Bovingdon stack at the time.

The article includes a link to a view of an ATC screen demonstrating the problem of overlapping labels:
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Old 22nd Oct 2004, 17:57   #2 (permalink)
 
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But controllers don't use the radar as the primary aide-memoire for managing a stack! I used SSR for 30 years and I do not believe there is any way to display all labels all the time clearly in busy airspace because there is not enough room on the radar display! In holding patterns the accuracy of track-keeping is such that often 3, 4 or 5 a/c will be exactly over the same point at the same time. OK. one solution is for one label to be switched off for a second or so to prevent "garbling". but it doesn't solve the problem of how to display everything.

The graphic was interesting - and I'll bet it came as a considerable surprise to the pilots and controllers working in the LTMA!!!
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Old 22nd Oct 2004, 18:25   #3 (permalink)
 
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Angry Hacan and John Stewart

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Old 22nd Oct 2004, 18:44   #4 (permalink)
 
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What a load of old cock. This is the sort of sensationalist, misinformed and downright inaccurate claptrap that gives us ATCO's and our over worked but professional system a bad name. "The controller could have called up a window with the aircraft's information". RUBBISH . complete tripe.
rant over. wasn't it windy today...........
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Old 22nd Oct 2004, 19:37   #5 (permalink)
 
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Yep, very windy! Spent a lot of time in the Lam hold over the last two days and at saber! Thought you boys and girls did a great job as usual, also liked the way that LHR kept us tight to the field and keeping the speed up to 4 miles, probably helped save a few minutes through the day!!

Anyway back to the thread gave us something to giggle about whilst on the ground waiting for the slot to improve. On a plus side made things much easier when making a PA to explain the holding system, " if you turn to the appropriate page in the times!"
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Old 22nd Oct 2004, 23:41   #6 (permalink)
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As a general comment relating to aviation stories in the media, I would urge any PPRuNe readers with the professional knowledge and inclination to correct or refute any inaccuracies in this or any other similar stories to write to the editor concerned.

Too often these journos get away with sensationalist reporting of aviation in the name of selling papers. When the media reports on aviation, the often fatuous arguments of anti-aviation pressure groups, such as the one in this article are quoted verbatim, only attracting the most flaccidly worded response from official bodies, such as the CAA. What is required is a response from knowledgeable individuals who support aviation with the same zeal as the antis oppose it.

To any journalists reading this, my specialist knowledge of aviation helps me to spot misinterpretations and fallacies in the majority of articles I read on the subject. To me this calls into question the validity anything else you write as with any other subject I am just a layman and can't filter what I read in the same way.
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Old 23rd Oct 2004, 07:15   #7 (permalink)
 
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Fortunately though the day was saved by 'the buzzer sounding on the controller's desk.'

Oh and the drop-down palette, another Swanwick/West Drayton confusion by the press methinks
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Old 23rd Oct 2004, 07:26   #8 (permalink)
 
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<<As a general comment relating to aviation stories in the media, I would urge any PPRuNe readers with the professional knowledge and inclination to correct or refute any inaccuracies in this or any other similar stories to write to the editor concerned.>>

Don't waste the stamp. Newspapers are a law unto themselves and by the time your letter arrrives the subject matter will be "history" and they'll be writing tripe about something else. You probably won't even get an acknowledgement but if you do it'll be a "standard" stereotype response.

ATC units where I worked were often visited by journalists who were writing various articles and looking for "background", or in one case they wanted to feature a "lady controller". They wouldn't provide draft copies for inspection prior to publication and the results were often extremely embarrassing and very distressing for those involved.

In my book there are two types of rubbish - what goes in your dustbin and what you read in the media.
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Old 23rd Oct 2004, 11:09   #9 (permalink)
 
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Since watching colleagues misrepresented in the interests of 'a good story' my rule has been to avoid speaking to the media and always to refuse TV crews permission to film on my aircraft. If the boss insists then he can fly the trip.
It could be argued that they'll just go and make up a story; well, yes but it won't have a quotation from or video of a professional on it to support the fiction.
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Old 23rd Oct 2004, 11:27   #10 (permalink)
 
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Trying to ignore all the rubbish in the article, there are still points to learn from it.

Garbling (label overlap) is a problem. So why do NATS pursue a policy of minimal flow restrictions and therefore maximum airborne holding ?

Stack delays could easily be managed at 10-15 minutes yet anytime the landing rate at Heathrow is reduced (eg strong winds) EATs are allowed to increase above 30 minutes, filling every inner and outer hold and exacerbating the radar garbling problem.
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Old 23rd Oct 2004, 11:57   #11 (permalink)
 
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Unfortunately it only takes two aircraft in the hold with minimal delay for label garbling to occur,hence the need for an accurate strip display at all times.
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Old 23rd Oct 2004, 23:02   #12 (permalink)
 
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The trouble is that good ATC is very bad television
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Old 24th Oct 2004, 01:23   #13 (permalink)

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fish

Ahh, you people are spoiled! You think that piece was crap journalism? That is a well-reasoned and low key description of something pretty near the facts. You want to know what real crap journalism is? Try this, from the local paper in my small town. Front page of course, and the inevitable Seconds From Disaster headline accompanying!

............................................................ ....................PASSENGER TERROR

TWO passengers at the centre of a potential air disaster are outraged at the wall of silence surrounding the incident.
World travellers Ran and Robyn MacDonald were sitting in the sixth row of the Qantas Boeing 717 which almost landed on the Bruce Highway south of the City Gates on May 29.

They know it might have been only a matter of seconds between them surviving and disaster.

The plane was just 200 metres (600 feet) off the ground when it aborted the landing.

Mackay aviation experts said it was likely, from that altitude, the plane would have taken only about 60 seconds to land and would have been been travelling between 180kmh and 200kmh on touch down.

The couple has travelled the world for the past 30 years.

They compared the fear they felt during the ordeal to that experienced while on board an Egypt Air jet air bus which aborted a take-off at high speed and skidded down the runway.

"We went in for a normal descent, although the pilot seemed to be on and off the throttle quite a bit," Mrs MacDonald said.

We were heading down at probably a 45-degree angle (!!!!!!) and then we felt the plane start to ascend steeply. It pushed us back in our seats a bit but I was still looking out the window," Mrs MacDonald said.

"I heard the landing gear come down before the first attempt and the cabin crew was told to be seated and prepare for landing a couple of minutes before we made the ascent.

"There was a public announcement and some of the passengers were talking among themselves before that, but after the announcement it was silent."

Mr MacDonald said the plane then circled for about 30 minutes before a second attempt to land was made.

"We were just up there circling in zero visibility. There was nothing but cloud. It was a complete white-out.

"It was real white-knuckle and sweaty palms stuff for me, very worrying. When I got home I made a note of it in my diary: May 29, scary landing.

"I kept thinking there must be something very wrong with landing systems if it took the pilot half an hour to be able to attempt another landing."

The couple called for an urgent review of landing safety procedures and scolded authorities for failing to inform the public or the Mackay Port Authority of the incident.

"This is a matter of public safety," Mr MacDonald said.

"It shouldn't be hushed up. This should have been brought to light immediately and the problems addressed.

"Mackay Port Authority, Australian Transport Safety Bureau (ATSB) and QantasLink need to urgently review and upgrade their landing and safety protocols," he said.

End of article. (The exclamation marks were mine, of course!)

Thank your lucky stars you have the Times!
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Old 24th Oct 2004, 16:00   #14 (permalink)
 
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blimey cobber, what a load of old dingo dung.
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Old 26th Oct 2004, 16:01   #15 (permalink)
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Thanks to Mrs Jerricho, she has convinced me (as well as Bren and Binos) not to fire off an email to the editor regarding this sensationalist tripe.

Del Prado, interesting comments there about points to learn from.

Quote:
Garbling (label overlap) is a problem. So why do NATS pursue a policy of minimal flow restrictions and therefore maximum airborne holding
Yes, lable garbling does occur. However, as Hammy indicates, that's why flight progress strips are also used (or whatever form of flight data recording and display), thus making it a non issue. In fact, the Heathrow Int Support controller often manages the stacks "procedurally", using pilot reports of leaving levels and maintaining to update flight data information. IMHO, I think it emphasises the need for accurate and legible flight data recording.

And regarding NATS flow policy, we all know flow control isn't an exact science, and all manner of variables can cause a 10 minute inbound delay to increase to 30 minutes. Conversley, if weather factors change or TEAMing is put into force (using both runways for arrivals) a landing rate can increase considerably, eliminating all delay (and leaving no jets to play with).

Last edited by Jerricho; 28th Oct 2004 at 21:53.
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Old 26th Oct 2004, 16:38   #16 (permalink)
 
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Quote:
In holding patterns the accuracy of track-keeping is such that often 3, 4 or 5 a/c will be exactly over the same point at the same time. OK. one solution is for one label to be switched off for a second or so to prevent "garbling". but it doesn't solve the problem of how to display everything.
I seem to remember learning about a tool that displays the hold vertically. Using mode S maybe? Possibly part of iFACTS?

Unfortunately I then did the time honoured trick of forgetting about it when I walked out of the interview! I'm sure someone can elaborate.
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Old 27th Oct 2004, 00:58   #17 (permalink)
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the Vertical Stack Display

coming soon with Enhanced Mode S
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Old 27th Oct 2004, 01:26   #18 (permalink)
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coming soon with Enhanced Mode S
And a SMF "buzzer"?
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Old 27th Oct 2004, 11:41   #19 (permalink)
 
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Jerricho, yes the landing rate can vary considerably although it has got better since you went to Canada. (sorry couldn't resist )

Okay I take yours and Hammy's point about using strips and reverting to procedural control during times of garbling but by having to rely on procedural methods we're increasing the chances that a level bust or ATC error isn't spotted early enough. Quite simply, (ssr) radar is safer yet it's rendered almost useless in the stacks by excessive holding.

Hammy is right to say only two aircraft are required to cause garbling. Two aircraft in a hold MIGHT garble, eight in the same holding pattern WILL overlap.

As you say, delays can go from 10 to 30 minutes for all manner of unforseen reasons (weather, runway closure, etc). But once the delays are high we could be using flow control to bring them down to a sensible target.

Your assertion that TEAM can bring delays down to the point where we have no jets to play with isn't true. TEAM can only be used when delays are excessive (ie well over 20 mins) when EATS are no longer in force TEAM ceases. There will still be 20 minutes of holding in the stacks.
In fact TEAM only saves 5 or 6 minutes holding per hour.

This has always struck me as a latent risk in our operation and I don't think the benefits to customers of applying no flow control outweigh the safety risks associated with overloading the system.
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Old 27th Oct 2004, 12:48   #20 (permalink)
 
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Hate to get in the way of the age-old PPRuNe tradition of turning journos on the rotisserie, but where, pray (at risk of joining the barbecue) is the unforgiveable inaccuracy which not one post so far has bothered to point out?
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