Big Sky Field frequencies
Big Sky Field (S85) in Culbertson, MT has no control tower, so nobody is sequencing traffic here — you announce your own position on 122.8. Every frequency below is in the order you tune it. · Open on the map
All of Big Sky Field — runways, frequencies, charts and live weatherBefore taxi
- ASOS/AWOS 120.000
- An automated weather station reading the field conditions aloud — wind, visibility, ceiling, temperature and altimeter. It replaces ATIS at a field with no controller to record one. Get the altimeter setting before you descend below the transition altitude.
Taxi & takeoff
- CTAF 122.8
- The common frequency pilots use to announce themselves to each other at a field with no operating control tower. Nobody is controlling traffic — you are self announcing. Report your position and intentions on entry and on each leg of the pattern, and listen well before you transmit.
- UNICOM 122.8
- A ground station run by the FBO rather than the FAA, for fuel, parking and airport services. Use it for services. Where the field has no separate CTAF, the same frequency doubles as the advisory frequency.
What to say on 122.8
Nobody is sequencing traffic at S85, so every call is you telling other aircraft where you are. Open and close with the field name so a pilot tuned to a shared frequency knows which airport you mean — 122.8 is not unique to Big Sky Field.
- Inbound, 10 miles out
Big Sky traffic, Skyhawk one two three four five, one zero miles south, inbound landing runway 08, Big Sky.
- Entering the pattern
Big Sky traffic, Skyhawk one two three four five, entering left downwind runway 08, Big Sky.
- Before taking the runway
Big Sky traffic, Skyhawk one two three four five, departing runway 08, Big Sky.
Pattern direction is not always left here — check the S85 traffic pattern before you announce a leg. The Chart Supplement is authoritative if S85 publishes a call name that differs from the airport's. Full guidance →
Every S85 frequency, as one table
| ASOS/AWOS | 120.000 |
|---|---|
| CTAF | 122.8 |
| UNICOM | 122.8 |
Frequently asked
What is the CTAF at S85?
Big Sky Field is non towered. The common traffic advisory frequency is 122.8 — announce your position and intentions on entry and on each leg of the pattern.
What is the ASOS/AWOS frequency at S85?
ASOS/AWOS at Big Sky Field is 120.000. It is an automated broadcast, so there is no letter to report — just take the altimeter setting and wind.
More about S85
Frequencies from FAA NASR. For planning and education only; always verify against official sources.
Something here wrong or out of date? Report a data problem.