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

Mon Jul 6 07:59:42 CEST 2015

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Les,

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:
http://www.pprune.org/archive/index.php/t-114203.html

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
http://www.aavpa.org 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  www.rvs.uni-bielefeld.de