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Tuesday, January 12, 2016

One for the Ages

Last night, as we were getting ready for our arrival, the Paris-CDG Automated Terminal Information Service produced this:


Aviation communication is very narrowly scripted, which makes this nice touch stand out even more.



In case you care, here is the translation: ACARS Information Bravo, time 2115Z, transmitted to aircraft 915FD on 11 Jan 16 at 21:24Z. Expect Instrument Landing System approaches to runways 27R and 26L (i.e., landing to the west on the outboard runways), departures 27L and 26R (the inboard runways), Standard Instrument Departures 1A, 1B and 1Z. The runway is wet. Transition level (changing from standard to local altimeter on descent) is 6,000 feet on standard. Make sure to hold short of the departure runway after clearing the landing runway. ATC has recently decided to reduce radio congestion by no longer reading the frequencies of Tower and Departure control on handoff.

The weather: winds out of the west at 17 kts, visibility greater than 10 kilometers, scattered cloud at 1600 feet, broken cloud at 2000 feet. Temperature 7C, dewpoint 4C, local altimeter setting 991 hectopascals.

And yes, aviation chaotically mixes metric and English units.

13 comments:

erp said...

Not having the slightest idea what this means, I'll wait for someone to ask an intelligent question.

Bret said...

Oh. I just thought the point was that they're pretty random with which units they use when.

Clovis e Adri said...

I guess the point is that they wrote a book of a message with a language intended for very brief communication.


What surprises me more, really, is to learn that aviation communication is done by printing those little parking-ticket-like papers. Come on, couldn't it all appear in some screen? I am sure your heavy-machine wasn't so old it couldn't afford at least some old CRT screen...

Hey Skipper said...

Seriously, I have to diagram this?

The next to the last line "Nice flight Major Tom", in honor of David Bowie's passing.

erp said...

... now I'm really scared. I have no idea what the explanation means either. :-{

Hey Skipper said...

(Correction: Good flight, Major Tom)

You can easily be forgiven.

David Bowie was an extraordinary music star across a wide variety of genres. While I was never particularly a fan, there's no denying his nearly transcendent talent -- like Frank Sinatra, but more so.

However, completely unlike Frank, from everything I have read Bowie was also a decent human being.

Anyway, I thought it both surprising and fitting (Major Tom being an astronaut in the song I linked above) that someone paid tribute to him in an ATIS broadcast.

[Bret:] I just thought the point was that they're pretty random with which units they use when.

Not the point, but it is true. In the US it is all English except for temperature, which is in Centigrade. In Europe, visibility is in meters, altimeter in hecto pascals instead of inches, altitude and speed is in feet and knots. Elsewhere altitude is in meters, except in China, where it is in some impossibly goofy implementation of meters that requires jiggery pokery with the airplane to make it work.

The two constants are temperature and speed. Interestingly, all of it is completely arbitrary, except for altitude in feet and nautical miles. A nautical mile (6076 feet) is one second of latitude. That means that with math easy enough to do in one's head, knowing the distance between two points, and altitude to be gained or lost, one can calculate the required flight path angle. That's important to knowing what the airplane needs to be doing, or if something is even doable in the first place.

[Clovis:] What surprises me more, really, is to learn that aviation communication is done by printing those little parking-ticket-like papers. Come on, couldn't it all appear in some screen? I am sure your heavy-machine wasn't so old it couldn't afford at least some old CRT screen...

Of course we have a screen, as part of the Multifunction Control Display Unit (MCDU). But I just had to print this particular ATIS.

Barry Meislin said...

"...that requires jiggery pokery with the airplane to make it work."

Gosh, sounds like their stock market. (To be sure, they haven't been jigging very successfully of late....)

As for mixing apples and oranges, I kind of like the libertarian aspect of it all (though I'm sure NASA wasn't too thrilled).

To my mind, it sounds like a recipe for disaster. Seems that the fact that air disasters are so relatively few is further proof of the existence of a "Prime Mover".

File under: Walking that extra kilometer (but getting no closer)....

Clovis e Adri said...

Not being a Bowie fan, I'd never get that one. (While growing up in the 80 to 90s, Bowie was to me just one more of those strange 70's guy with weird makeup)

I saw that line and thought "I guess Skipper's name must be Tom". Dumb me.

Bret said...

Hey Skipper wrote: 'The next to the last line "Nice flight Major Tom"'

Oops. My eyes had glazed over from the gobbledygook before I got to that line.

I'm glad your flight (apparently) went better than the Major Tom's!

Bret said...

Clovis wrote: "Not being a Bowie fan..."

For how few fans he had (and he still had quite a lot), his impact on music was extraordinary. For example, "Space Oddity" (the song with Major Tom), may not seem particularly innovative today, but in 1969 it was many years ahead of its time.

But, if you weren't around to see his impact on music in real-time (or were too old to notice), then yeah, he'd mean nothing to you.

erp said...

Looks like Clovis and I have that gamut covered -- he wasn't born and I was a middle-aged 35 in 1969.

Bret said...

erp,

Yes, perhaps it's true that I had you in mind when I wrote "too old to notice." :-)

Clovis e Adri said...

Bret,

Taking a look at that song, I have two observations.

(1) It looks like a reasonably good piece of rock.

(2) But comparing with everything people were doing in 1969, I can't figure out why you say that was particularly influential at all. The guitar distortions techniques and riffs he is using were being widely used for a few years by then.