Re: [SystemSafety] Chicago controller halts Delta jet's near-miss....

From: Peter Bernard Ladkin < >
Date: Mon, 06 Jul 2015 07:59:42 +0200

Hash: SHA256


I don't see that talking to pilots who are not familiar with and not used to working with US ATC is going to lead to any insights about safety in US ATC communications in general or the Midway incident in particular.

  1. US ATC terminology is somewhat different from ICAO. This is well known, and they are not the only such land. I remember having discussions on the old bluecoat list a decade and a half ago, and I think it still crops up on PPRuNe every so often.

One old chestnut is "fly runway heading". The US definition is to continue flying the magnetic heading of the extended runway centerline. The old UK definition used to be to track the extended centerline. These are different, and I believe led to occasional misunderstandings when crews flew in the others' airspace. The UK dropped use of the term and adopted another one. You can find lots of discussions of this via Google: here is one on PPRuNe from eleven years ago, when it still had a high proportion of expert and thoughtful contributors:

Your acquaintance Bill wrote:

[begin quote]
On practical level, the current international ATC protocols should be enough, but good luck getting the US to change their can-do and casual attitude to ATC coms. [end quote]

The US ATC protocols are law in the US. That's why they use them. One might as well say "good luck getting Australians to drive on the right." This would have very little, if anything, to do with intra-Australian road safety. Similarly, the difference between domestic-US ATC protocols and those of other lands has very little to do with US traffic safety when only US crews are involved.

2. Accent, delivery and language. Yes, it's different. It works for everybody who flies there just as well, and often very much better, as ATC-pilot communications anywhere work.

Controllers at international US airports make allowances for crews without native English. All aviators are supposed to be able to communicate in English, but many non-US crews from certain parts of the world are barely able comprehensibly to do so and clearances are regularly misunderstood or not followed as ACKed. That doesn't arise at Chicago Midway, which is a domestic airport.

On 2015-07-06 03:46 , Les Chambers wrote:
> ....When I hear the beginning of the recording, my instant initial reaction is that I am
> listening to a foreign language. In the next few seconds, as a native English speaker, I begin
> to attune to the speed and accent, but still struggle with the illogical order in which the
> information is given, combined with the speed of delivery.

The writer confirms his sparse understanding of the communication situation.

There are people in aerospace who have been working for decades on communications and psychology and incidents such as these: why people misunderstand communications and how pilots and ATC get into situations in which they do not share a common understanding of the clearance situation. Many of them are at NASA. As Chris pointed out, there have been and are committees in Europe and elsewhere working on call-sign confusion. In Australia, you might like to contact the AAPA for some expert commentary (I addressed their annual conference in 2005 and gave a course at the ATSB).

PBL Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany Je suis Charlie
Tel+msg +49 (0)521 880 7319

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systemsafety_at_xxxxxx Received on Mon Jul 06 2015 - 07:59:54 CEST

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