Saint Louis Downtown Airport (KCPS), Illinois
Landing essentials
Whether you can land, whether you can refuel, and how customs works here.
Overview
St Louis Downtown Airport (KCPS) sits in Cahokia, Illinois, roughly 10 nautical miles from the St Louis metro area, and serves as a towered, public-use reliever field with three paved runways. The facility handles a mix of business aviation and training activity, supported by both 100LL and Jet A fuel, with FAA TFMSC data reporting 6,570 business aviation operations against a 2025 annual total of 9,840. Its position near several other regional airports, including St Louis Lambert International about 14.70 nautical miles away, makes it a practical alternative for operators working the greater St Louis area.
Runways
Saint Louis Downtown Airport has three paved runways. The longest, 12R/30L, is 7,002 ft long and 150 ft wide, with an asphalt surface.
Runway geometry from published threshold coordinates. Not for navigation.
Runways are listed longest first.
Source: FAA Form 5010.
Fuel and airfield services
Saint Louis Downtown Airport has Jet A and 100LL available on the field. Fueling is available 24 hours a day, every day, and the airport has an operating control tower.
Source: FAA Form 5010 / NASR.
Customs
Saint Louis Downtown Airport does not clear customs. The nearest port of entry is Saint Louis Lambert International (KSTL), 15 NM away.
Source: CBP list of ports of entry.
Business aviation traffic
Saint Louis Downtown Airport recorded 6,570 business aviation movements in 2025. Traffic peaks in September. Business aviation traffic at KCPS is concentrated in the spring and late-summer months, with September posting the highest monthly count and February the lowest, according to FAA TFMSC data.
Business jet movements, FAA TFMSC count. Peak month September, 675 movements in 2025.
Source: FAA TFMSC, business jet movements, 2025.
Climate
Saint Louis Downtown Airport averages 15.9 days above 90°F in July and 24.9 freeze days in January. July is the warmest month, with average highs of 89.0°F, and January the coldest, at 40.2°F.
Weather station is on the field. Some values are estimated by the agency. 1991–2020 climate normals.
Source: NOAA NCEI.
Operating constraints
Saint Louis Downtown Airport has published operating constraints in four categories: weight restrictions, runway notes, pavement strength and other notes.
All taxiways except taxiway B require prior permission for aircraft over 120,000 pounds.
The MALSR on runway 30L activates when the control tower is closed. The REIL on runway 30R is controlled via CTAF. The HIRL on runway 12R/30L presets to medium intensity when the control tower is closed. The MIRL on runways 12L and 30R is not available when the control tower is closed. The PAPI on runways 12R and 30L operates continuously.
Runway 05/23 is not available for Part 121 or Part 380 operations involving scheduled passenger-carrying flights with more than 9 passenger seats, or non-scheduled passenger-carrying flights with more than 30 passenger seats. No Part 121 or Part 380 operations are permitted on this runway except for taxi movement.
Runway 12L/30R is not available for Part 121 or Part 380 operations involving scheduled passenger-carrying flights with more than 9 passenger seats, or non-scheduled passenger-carrying flights with more than 30 passenger seats. No Part 121 or Part 380 operations are permitted on this runway except for taxi movement.
PCR VALUE: 400/F/D/X/T
Waterfowl are present on and in the vicinity of the airport.
Surface markings are faded.
Be alert for student training and helicopter operations.
Surface conditions are not monitored between 2100 and 0700 local time.
Source: FAA Chart Supplement.
Nearby airfields
Saint Louis Downtown Airport has five airfields within 24 NM. The closest is Saint Louis Lambert International (KSTL), 14.70 NM northwest.
Part of the St. Louis area.
Source: Skystar calculation from official coordinates.
Skystar at KCPS
We arrange catering, fuel and trip support here. Supplier prices reach you unchanged; our coordination fee sits on its own line.
The same order, priced two ways.
$2,400.00 catering order at KCPS.
Unchanged.
What the kitchen invoices us is what your quote reads.
One line, fixed.
It does not move with the size of the order.
At cost.
Passed on at the exact amount the processor took.
Market practice figures are industry averages, not a specific competitor.
Frequently asked questions
What is the longest runway at KCPS?
KCPS, St Louis Downtown Airport, has three paved runways, and the longest is 12R/30L at 7,002 feet by 150 feet with an asphalt surface. A second hard-surface runway, 12L/30R, measures 5,301 feet by 75 feet on concrete. A shorter crosswind runway, 05/23, spans 2,799 feet by 75 feet on asphalt. All three runways are paved, giving dispatchers flexibility for aircraft sizing across most business aviation types operating into this facility.
Are there restrictions on Part 121 or Part 380 operations at KCPS?
St Louis Downtown Airport (KCPS) restricts two of its three runways for certain scheduled and non-scheduled passenger operations. Runway 05/23 and runway 12L/30R are both unavailable for Part 121 or Part 380 operations carrying more than 9 passenger seats on scheduled flights, or more than 30 passenger seats on non-scheduled flights. The only exception on these runways is taxi movement, not takeoff or landing under those rules. Operators planning larger passenger flights should route those operations through runway 12R/30L instead.
Is customs clearance available onsite at KCPS?
St Louis Downtown Airport (KCPS) does not have onsite customs processing. The nearest customs facility is St Louis Lambert International (KSTL), located approximately 14.70 nautical miles away. Crews requiring customs clearance need to plan a stop or ground transfer to that airport rather than expecting service directly at KCPS. This distance should factor into routing and scheduling decisions for any international arrival.
What weight restriction applies to taxiway movement at KCPS?
At St Louis Downtown Airport (KCPS), all taxiways except taxiway B require prior permission for aircraft over 120,000 pounds. Operators planning to move heavier aircraft on the field should arrange this clearance in advance rather than assuming unrestricted taxi access. Taxiway B is the exception, though the remark does not specify its own weight limit. This restriction is relevant to dispatchers coordinating heavy jet or cargo movements through the airfield.
Does KCPS see seasonal variation in business aviation traffic?
Business aviation traffic at St Louis Downtown Airport (KCPS) is concentrated in certain months rather than spread evenly across the year, according to FAA TFMSC traffic data for 2025. September recorded the highest monthly count at 675 operations, while February saw the lowest at 420. Spring and late summer months, including March, July, and September, show noticeably higher volumes than the winter months. Dispatchers scheduling flexible trips may find lighter conditions in January, February, and December.