[Peetwo]

Good catch Gobbles...

Courtesy the other Aunty:

Sydney Airport plane tracking system regularly failing, workers fear for passenger safety


Exclusive by national technology reporter Jake Sturmer Updated yesterday at 7:25pm



Photo
Airservices Australia still uses the system, allowing them to land more planes per hour.
ABC News: Giulio Saggin


A critical plane tracking system at Australia's busiest airport is failing regularly, leaving air traffic controllers deeply concerned about safety.

Key points:

• 15 failures detected in WAM system in last month alone, according to controller fault logs
  
• Earliest recorded failure has been at 9:10am
  
• At no time should "expediency take precedence over safety", Civil Air says
  
  

The failures have so far not resulted in any major safety incidents at Sydney Airport, but air traffic controllers fear it is only a matter of time.

When the system fails, planes disappear from one screen and are only visible on the older, slower radar screen.

In the last month alone, there were 15 failures detected in the Wide Area Multilateration (WAM) system, according to controller fault logs obtained by the ABC.

Despite the problems, Airservices Australia continues to use the system, which allows them to land more planes per hour.

The organisation, which manages Australia's airspace, has acknowledged some concerns about instability and agreed to only rely on the system between 7:00am and 9:00am — peak times during weekdays.

The earliest recorded failure has been at 9:10am and controllers believe the use of the entire system should be suspended until it is fixed, or staff get the right training.

Do you know more? Email investigations@abc.net.au

Internal defect reports describe WAM problem as 'systematic'


Photo A controller's log of failures in the WAM system from March 20 to April 18.
Supplied

The air traffic controllers' union, Civil Air, believes at no time should "expediency take precedence over safety".

What is Wide Area Multilateration (WAM)?

• In order to land more planes per hour during poor visibility conditions, such as low cloud, air traffic controllers use a sophisticated surveillance system called WAM
  
• WAM is faster than radar
  
• Allows controllers to land planes on Sydney Airport's parallel runways, where they are separated by a few seconds (1 kilometre)
  
• When WAM fails, planes disappear from one screen, only appearing on the separate radar — leaving controllers unable to accurately determine if aircraft are potentially heading into one another
  
  

The ABC has seen emails to management where staff express "no confidence" in the system and fear that "there is a norm forming of acceptable instability".

Controller logs of faults obtained by the ABC from between March 20 and April 18 this year show the system has failed 15 times and internal defect reports have described the problem as "systematic".

If the aircraft are not 2 nautical miles (3.7 kilometres) apart when the WAM fails, controllers have to divert all planes on final approach to the runway — known as a multiple breakout — which is a scenario that controllers have not been trained for.
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Video 2:10 Passenger safety concerns after plane tracking system fails
[url=http://mobile.abc.net.au/news/2016-05-02/passenger-safety-concerns-after-plane-tracking-fails/7377720]ABC News

Instead of breaking out two planes, controllers could be breaking out up to six and "tripling their workload", according to Civil Air.

"The reality is we haven't simulated breaking out six aircraft," Civil Air president Daryl Hickey said.

"These people can deal with these complex situations quite well but the reality is we haven't trained for it, we haven't simulated for it.

"So we couldn't say with any certainty what might happen."

Controllers have not yet had to run the untrained multiple breakout scenario — as when the WAM has failed, the planes have been more than 2 nautical miles apart.

On its website, Airservices Australia states WAM and "Parallel Runway Monitoring (PRM) can potentially cut air traffic delays caused by poor weather by as much as 80 per cent".

This can have significant flow-on effects — if the number of planes per hour drops significantly, more flights would be placed into lengthy holding patterns and some would most likely be cancelled.

Email sent to staff as controller dissatisfaction builds

Air traffic controller concerns have been building and management was forced to quell dissatisfaction two weeks ago.

If you're unable to identify what's causing the fault then we don't think you can say with any certainty that it won't happen at an earlier time in the day.

Civil Air president Daryl Hickey

"We understand that several of you are not satisfied that we have followed the [Safety Management System] in our risk assessment and management of the WAM issue," the email to staff read.

"The control to only use PRM [and using WAM] between the hours of 7:00am to 9:00am is providing the same level of operational risk as we have always carried.

"We do not expect to have a failure between the hours of 7:00am to 9:00am.

"There have been no failures, whether we are in PRM or not, between the hours of 7:00am to 9:00am.

"This is why we are only going to run PRM between 7:00am to 9:00am. This is a standard aviation risk-based approach."

But that is not a presumption Civil Air accepts.

"If you're unable to identify what's causing the fault then we don't think you can say with any certainty that it won't happen at an earlier time in the day," Mr Hickey said.

Airservices Australia is also forcing airlines to carry 50 per cent more holding fuel (30 minutes extra as opposed to 20 minutes) during PRM operations.

In a statement, Airservices Australia acknowledged an "issue" but said it maintained "multiple redundancy in all its surveillance systems".

"Any single system unavailability does not impact aviation safety," a spokesperson said.

"Our highly trained controllers have the skills and knowledge to manage system unavailability.

"Airservices has been working closely with the vendor since December 2015 to resolve an issue … which can have some impact on the number of landing aircraft during poor weather."

Losing aircraft, software glitches...yada..yada, reminds me of some of the issues highlighted in this past post of mine - ASA - She'll be right mate??:

..Airservices Australia considered a similar limitation for the 787 fleet last year because of the same software problem, but the consequences would have been more severe. Unlike Canada, Australia mandates that all aircraft above 29,000ft must have ADS-B transponders.


A blacklisted aircraft would be treated the same as one that is not equipped with ADS-B, forcing 787 operators such as Jetstar to remain below 29,000ft while in Australian airspace.


Ultimately, Airservices Australia decided to accept the “risk” of allowing 787s to operate in ADS-B-mandated airspace with standard separation distances, ICAO’s reports show...

...[b]Finally, the agency blacklisted the 787 on surface management systems at three airports – Brisbane, Melbourne and Sydney. But the airport restriction was only intended to raise awareness about the issue, as other airport position monitoring systems can pinpoint the 787’s location on the surface...

...[b]Around four months later, Airservices Australia noticed a similar problem when a Jetstar 787 appeared to deviate “significantly” off-track, then suddenly “jump” back to the planned route on a controller’s screen, the ICAO documents say...[/b][/b]

MTF...P2