Sunday, December 18, 2005

A question from Caz......

Caz has posted the following question:

Hello its Caz again! A quick question, what does it mean when pilots say 'We are a Boeing 777 (understand that bit!) with information Lima? or Romeo? or Papa?' It always seems to be a different letter but i just don't understand what that bit means & i can't find it anywhere in my books!

This relates to the continuous weather broadcast given out on a dedicated frequency at airports. Remember my post regarding Gatwick frequencies mentions the 'ATIS' frequency of 136.525? ATIS stand for 'automatic terminal information service' - it is a continuous broadcast of the current weather conditions at that airport and it is typically updated every 20 to 30 minutes. This is just an example, but say the weather broadcast at 8am in the morning is known as 'information alpha' when it is next updated at say, 8.30am it becomes 'information bravo' and so it goes on throughout the day until the update becomes 'information zulu' and it then starts all over again at 'information alpha'. When an aircraft calls approach control and advises his aircraft type along with 'information alpha' for example, the controller immediately knows which weather broadcast the pilot has listened in to on the ATIS frequency. If there has been a further update with any changes in weather conditions this will be reported to the pilot.

I hope I have explained this clearly enough? If there are still any queries please let me know.

1 comment:

Caz said...

Thank you again for your help! It was beginning to bug me as i kept hearing it and couldn't figure out what it meant! I have a GRE PSR 282 scanner and my father in law has just put an aerial (skyscan Airmaster i think!?) up on the side of our house for me and i now get to hear 2 way conversations which has greatly improved my listening enjoyment! I can now get Gatwick ground and Tower which i couldn't before! I also tuned in to the London FIS on 124.6 which you recommended in an earlier message and that does make quite interesting listening. I just wish i had more time to spend on it though! One more thing before i sign off, i have a couple of charts (Aerad En Route UK(L)2 and CAA England South Topographical 1:250 000) and i am desperately trying to see what flight routes go over my area as we have planes going over our house most of the day but especially early morning and i am desperate to know what frequency they could be on. I know you mentioned WILLO and frequency 133.175 in an earlier message so is it likely to be that one. Am i looking at the right sort of charts?? Sorry to keep asking but you are my only font of knowledge at the moment and i am very keen to keep learning!! Thank you again!