St Louis Downtown Airport frequencies

St Louis Downtown Airport (CPS · KCPS) in Cahokia/St Louis, IL is a towered field, staffed 0630-2200. Every frequency below is in the order you tune it, from the first call to the handoff on climb out. · Open on the map

All of St Louis Downtown Airport — runways, frequencies, charts and live weather

When the KCPS tower is closed

The tower is staffed 0630-2200. Outside those hours St Louis Downtown Airport has no operating control tower: it becomes a self announce field on 119.925, and separation from other traffic is yours, not a controller's. Report your position and intentions on entry and on each leg of the pattern.

Runway lighting is often pilot controlled once the tower closes — check the KCPS airport page for the click sequence, and what to say on the radio.

Before taxi Downtown

ATIS 121.45
A recorded loop of the field's weather, active runway and any notices, updated hourly or whenever conditions change. Listen before your first call, and tell the controller which letter you have so they do not read it to you again.
Clearance 118.275, 121.8 (WHEN TWR CLSD)
Clearance delivery issues your IFR clearance, and at busier fields your VFR departure instructions and squawk code. Call before you request taxi, with the ATIS letter and your intended direction of flight.

Taxi & takeoff Downtown

Ground 121.8
Ground control owns every taxiway and inactive runway on the field. Call for taxi with your position and destination on the field. You need an explicit clearance to cross any runway, including one that is not in use.
Tower 119.925
Tower owns the active runways and the surrounding surface area. Call before entering the surface area inbound, and hold short until you are cleared to take off or to cross.

Departure & arrival Saint Louis

App/Dep 123.7
One radar controller working both arrivals and departures — normal at a smaller TRACON. The same frequency takes your climb out and your inbound call.

Also

CTAF 119.925
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 122.95
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.
By procedure & sector (6 more)
119.15BUUDD STAR, FARMR STAR
128.1DELMA STAR, DIXEE STAR
307.05DELMA STAR, DIXEE STAR
335.5BUUDD STAR, FARMR STAR
371.875APCH/P DEP/P
379.3LCL/P
Every KCPS frequency, as one table
ATIS121.45
Clearance118.275, 121.8 (WHEN TWR CLSD)
Ground121.8
Tower119.925
CTAF119.925
UNICOM122.95
App/Dep123.7

Frequently asked

What is the tower frequency at KCPS?

St Louis Downtown Airport tower is 119.925, calling "Downtown Tower". The tower is staffed 0630-2200.

What frequency do I use at KCPS when the tower is closed?

Outside 0630-2200, St Louis Downtown Airport has no operating control tower and becomes a self announce field. Use 119.925 as the CTAF and report your position and intentions — there is nobody to clear you, so separation is yours.

What is the ground frequency at KCPS?

Ground control at St Louis Downtown Airport is 121.8. You need an explicit clearance from ground to cross any runway while taxiing, including one that is not in use.

What is the ATIS frequency at KCPS?

ATIS at St Louis Downtown Airport is 121.45. Listen before your first call and report the letter you have.

What is the approach frequency for KCPS?

App/Dep for St Louis Downtown Airport is 123.7, working as "Saint Louis". Call inbound for flight following or to begin an instrument approach.

Where do I get my clearance at KCPS?

Clearance delivery at St Louis Downtown Airport is 118.275, 121.8 (WHEN TWR CLSD). Call before requesting taxi, with the current ATIS letter and your direction of flight.