Jsuen From United States of America, joined Aug 2001, 211 posts, RR: 0 Reply 2, posted (11 years 9 months 4 weeks ago) and read 1906 times:
The Automatic Terminal Information Service is a recorded/computer generated message that gives weather and airport information. Each recording is given a phonetic alphabet (Alpha, Bravo, Charlie...) so pilots know which version they have. If ATC says ATIS has been changed to Tango, flight crews should listen to ATIS again if they don't have the Tango version. Sometimes you'll hear "Carrier 123 with Bravo". This tells the controller that the crew already has ATIS Bravo and the controller doesn't need to go over that information, unless it has been updated to Charlie in the meantime.
Bio15 From Colombia, joined Mar 2001, 1089 posts, RR: 7 Reply 3, posted (11 years 9 months 3 weeks 6 days 23 hours ago) and read 1871 times:
No, there doesn't have to be a great change in weather for an ATIS update. Just a change in QNH (barometric pressure) could represent altimeter deviations of a hundred feet or so, which must be promplty reported.
H. Simpson From United States of America, joined Mar 2001, 949 posts, RR: 3 Reply 4, posted (11 years 9 months 3 weeks 6 days 21 hours ago) and read 1853 times:
by the way, if there is significant weather change(thunderstorms...) the controller will actually read out a very brief weather report over the ATC frequencies(ie. approach, departure), not necessary on ATIS.
Woodreau From United States of America, joined Sep 2001, 932 posts, RR: 7 Reply 5, posted (11 years 9 months 3 weeks 6 days 20 hours ago) and read 1830 times:
At least in the US, ATIS msgs are changed at least every hour, even though there is no significant change in the wx. ATIS can change if they change runways, announce ILS outages, or ramp/taxiway closures, etc.
Good judgement comes from experience. Experience comes from surviving bad judgement.
KAUSpilot From United States of America, joined Jan 2002, 1958 posts, RR: 34 Reply 7, posted (11 years 9 months 3 weeks 6 days 15 hours ago) and read 1802 times:
The ATIS is usually only updated hourly, unless something happens that needs to be broadcasted before the hour is up.
Here in austin, they'll often make a new atis broadcast for "birds on and in vicinity of airport". Other reasons would be a wind shift (especially one major enough to change the active runways).
If the visibility is suddenly reduced due to precipitation, or low cielings suddenly move in, you'll also get a quick change on the ATIS.
Sometimes, like tonight, you'll listen to the ATIS, and right after you switch frequencies to go on approach ATC will put a new atis on. So you'll say "approach, cessna NXXXX at XXXX over XXXX with uniform", and ATC might say "cessna NXXXX Squawk XXXX, fly heading XXX, information victor is now current" so then you'd listen to the ATIS again to get victor.