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by Animats2 hours ago |
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upvoteby Animats1 hours ago|
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Update:

    ATCSCC ADVZY 120 DCC 11/13/2026 NATIONWIDE GROUND STOP

    MESSAGE: 
 

    EVENT TIME: 13/2245 - 14/0400
    DESTINATION AIRPORT:ALL
    FACILITIES INCLUDED: ALL
    EXPECT UPDATE:0400Z
    REASON: COMMUNICATIONS FAILURE           
    REMARKS: THE FAA COMMAND CENTER GROUND STOP REMAINS IN EFFECT. AS
    ENROUTE FACILITIES RECOVER, FLIGHTS WILL BE ALLOWED TO DEPART
    THROUGH COORDINATION WITH THE AIR TRAFFIC CONTROL SYSTEM COMMAND
    CENTER. 

    EFFECTIVE TIME: 132246-140430

    SIGNATURE: 26/11/13 22:46
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upvoteby Animats2 hours ago|
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As of 1345, "No ADVISORY Available for today."

There's a query form for looking up old advisories, and it's not returning anything for the last 15 days.

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upvoteby ryanisnan2 hours ago|
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What does this mean? "DCC HAS IMPLEMENTED EXTENDED FLIGHT PLAN DROP TIMES TO 240 MINUTES FOR ALL ENROUTE CENTERS DUE TO NATIONWIDE COMMS FAILURE."
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upvoteby geocrasher2 hours ago|
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It means that flight plans (which include departure time) will stay in the system longer after the departure times are missed, so that IFR flight plans will not need to be re-filed. In other words, flight plans have a longer TTL.

This will ease the pain of getting things moving again, assuming they fix it by the time the 4hr window passes.

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upvoteby Animats2 hours ago|
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Normally, a flight plan must be filed with the FAA no later than 60 minutes before it's needed. That's been extended to 240 minutes.

So the flight planning system is having problems.

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upvoteby tjohns2 hours ago|
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You can definitely file a flight plan later than that. 30 minutes before departure is the recommended filing time (per AIM 5-1-6), but you can even file for an immediate departure. It's just that at less then 30 minutes additional delay is possible, depending on backend handling and human processing. But in most cases the strip will print within a minute or two of submitting the flight plan.

But also, this is about when the flight plans expire out of the system if they're not activated for departure - so it's saying unused flight plans won't be deleted for 4 hours, so pilots won't have to refile for departure.

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upvoteby pandemic_region1 hours ago|
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Why do all avionic systems communicate in caps?
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upvoteby tjohns1 hours ago|
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Most of these systems started out as teletype printers, back in the day. The teletype systems only had an all-caps character set.

Aviation is global, and we still need to interop with countries and airports that still use actual teletype. So the legacy protocols still remain, even though much of it is tunneled over IP links now.

Also: The keyboards used in both airplanes and in ATC facilities are often special reduced-footprint keyboards without shift/caps keys. (They're also often ABC layout rather than QWERTY.) So there's that, too.

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upvoteby shrx29 minutes ago|
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Does anyone still use actual teletype?
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upvoteby tjohns18 minutes ago|
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Actual teletype machines? No. (Though flight strip printers used at ATC consoles are basically mini teletype printers.)

However, AFTN (used for disseminating flight plans and weather between ATC facilities) still uses landline modems running TTY-originated protocols.

In the US we've moved moved off AFTN in favor of AMHS/X.400, as have most countries - but my understanding is there's still some last holdouts that haven't fully switched over.

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upvoteby Symbiote1 hours ago|
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So they can be heard over the engine noise.
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