ATIS and AWOS
Weather is one of the most important parts of flight planning. At first, it doesn’t make a whole lot of sense why pilots would care about things like the temperature, dew point, cloud ceiling, etc. Let’s start off with temperature. The outside temperature doesn’t affect the aircraft as much as you would think. However, ice, frost, and density altitude do play a very important part in how an aircraft performs. As you can probably guess, it is not smart to fly with snow, ice, or frost on the aircraft, as the wings won’t produce as much lift, and many instruments just won’t work accurately. Also, a dead engine over the Alaskan Bush or Lake Superior usually doesn’t make for a happy flight (such as a Civil Air Patrol or Coast Guard search). Summer usually has fairer weather, but summer storms can make for very, very bumpy rides. And about density altitude: This name makes little sense, for the higher the density altitude, the less dense the air is. This could better be explained as performance altitude. (As I’m not yet a private pilot, I don’t know a ton on that, but I’m sure that John and Martha King would be happy to sell you a private pilot course.) Now, let’s get to ATIS and AWOS.
ATIS (Automatic Terminal Information Service) is usually found at reasonably large airports with lots of controllers. The controller will record a tape of the last weather update, and put a letter with it. For those of you who don’t speak the Air Traffic Control language, here is the list of letters:
Now, let’s look at what this report for Montgomery Field in San Diego means.
Montgomery airport information Hotel, 2159 Zulu. Wind: 238 at 8. Visibility: greater than 20 miles. Sky condition: few clouds at 5,800. Temperature: 18. Dew point: 10. Altimeter 2990. Visual runway 28R and Visual runway 28L in use. Landing and departing runway 28R and runway 28L. VFR aircraft say direction of flight. All aircraft read back hold short instruction. Advise controller on initial contact you have Hotel.
In other words, this is:
Montgomery airport information Hotel, 1: 59 PM Pacific Standard Time. Wind: coming from 238 degrees at 8 miles per hour. Sky condition: few clouds at 5,800 feet. Temperature: 18 degrees Celsius. Dew point: 10 degrees Celsius. Set your altimeter to 29.90 inches of barometric pressure so it will tell you your correct altitude. IFR is using the Visual approach to runway 28 right and runway 28 left. VFR aircraft tell the controller your position, altitude, and intentions. All aircraft acknowledge the hold short of runway instruction. Tell the controller on your first transmission that you have Information Hotel.
For the fun of it, let’s look at this rather unlikely ATIS report for Ronald Reagan/ Washington National airport in DC.
Washington airport Information Charlie, 1256 Zulu. Wind: 012 at 23 gusts at 28. Visibility: 3 miles in snow. Sky condition: ceiling 300 overcast. Temperature: -8. Dew point: -9. Altimeter 2950. ILS runway 1 in use. Landing and departing runway 1. All aircraft read back hold short instructions. Advise controller on initial contact you have Charlie.
Washington airport Information Charlie, 7:59 AM Eastern Standard Time. Wind: coming from 12 degrees at 23 miles per hour with gusts up to 28 miles per hour. Sky condition: ceiling 300 feet overcast. Temperature: -8 degrees Celsius. Dew point: -9 degrees Celsius. Altimeters should be set to 29.50 inches of barometric pressure. IFR is using the ILS approach to runway 1. Landing and departing runway 1. The airport is currently below VFR minimums. All aircraft read back the instruction to hold short of the runway. Tell the controller on your first radio transmission that you have Charlie.
As you can see, there’s a lot to it, but that’s important. However, you get the hang of it pretty quickly.
For an AWOS (Automated Weather Observing System) report, you’ll hear a computer voice give you the report. Here’s one for Sedona, Arizona.
Kilo Sierra Echo Zulu Automated Weather Observation, 1359 Zulu. Wind: calm. Visibility: greater than 20 miles. Sky condition: Clear… Temperature: 20 Celsius. Dew point: 8 Celsius. Altimeter: 2992.
Now that’s about the best weather that you could hope for. As you can see, the AWOS is pretty self-explanatory.
I hope that you’ve enjoyed reading this!
Keep the pointy side forward, the dirty side down, and by all means, please… stay out of the trees!
Have a great day!
(And yes, King Schools does use Montgomery Field, and yes, the Kings did use Sedona for one of the courses. And I would greatly recommend flight training through King Schools over Sporty’s.)