View Full Version : study about frequency of ACAS warnings
Presseportal: Technische Universität Braunschweig - Kollisions-Alarm im deutschen Luftraum / TU Braunschweig: Weltweit erste Langzeituntersuchung von Flugzeugkommunikation in Extremsituationen (http://www.presseportal.de/pm/73872/1316850/technische_universitaet_braunschweig)
Was in the papers today, but it'll probably be a few days before there is an English version out.
- 5 ACAS events / day over Germany
- every 7th pilot fails to carry out ACAS instructions correctly
- overall chance of midairs 10x higher than estimated previously
Dog E. Stile
10th Dec 2008, 09:59
How many of those ACAS warnings are 'nuisance' warnings due high rates of closure but where separation would not have been compromised?
5 ACAS events every day over Germany. How many flights in total are over Germany in one day?
Overall risk of midairs 10 x higher than previously estimated, but how high (low) was that risk before this study? We should deal in absolute risk values (e.g. 1 in 1000000, not relative (e.g. 50% higher) ones. Unfortunately the media realise that doesn't frighten as many people and thus sells fewer newspapers.
Context is everything.
I would be interested to read an English translation of the study, not any translations of media reports of the study, because the media are notoriously irresponsible when reporting anything requiring intelligence to understand.
Studie zur Flugsicherheit: Kollisionswarngeräte schlagen täglich Alarm - SPIEGEL ONLINE - Nachrichten - Reise (http://www.spiegel.de/reise/aktuell/0,1518,595420,00.html)
Most Spiegel articles make it to their English site after some time.
They are quoting the Professor of TU Braunschweig that from their study one collision every 30 to 50 million flight hours is extrapolated vs. an ICAO target of 1 billion.
Dog E. Stile
10th Dec 2008, 12:51
I'd personally prefer a target of zero collisions per 1 billion flights! :ooh:
Cheers
ChristiaanJ
11th Dec 2008, 16:56
- overall chance of midairs 10x higher than estimated previouslyI don't see that anywhere.
As you say in your second post, the news item says that "they extrapolated their data to arrive at 30 to 50 million flight hours per collision, which is well below the original ICAO target of 1000 million flight hours".
Of course this being the media, they don't tell you what flight hours, although one might guess 'total flight hours over Germany'.
I agree, it would be nice to see the original report.
- every 7th pilot fails to carry out ACAS instructions correctlyThe obvious answer to that is that the groundstations have no way of "looking into the cockpit". So they have no way of knowing how often it's a matter of "known traffic in sight, no action".