Chicago O’Hare KORD navigation aids and radio frequencies: ORD VOR/DME, ILS, ATIS, clearance, ground and tower, plus simulator caveats.
Chicago O’Hare (KORD) has the ORD VOR/DME on 113.90 MHz, runway-specific ILS/localisers and RNAV/GPS procedures. Core radio channels are arrival ATIS 135.40, departure ATIS 126.75, clearance 121.60, ground 121.75/121.90 and tower 120.75/126.90/132.70 MHz; Chicago Approach and Departure frequencies depend on the active sector and procedure.
For aviation and real-world flying, and for flight simulation, treat those figures as a planning baseline rather than a permanent clearance. KORD’s runway plan, sector split, chart amendments and temporary outages determine what is usable for a particular operation. Check the effective KORD approach plates, airport diagram and frequency data before flying.
KORD navigation aids at a glance
KORD combines a conventional VOR/DME with runway-specific precision approaches and satellite-based procedures.
| Aid | Frequency or source | Purpose |
|---|---|---|
| Chicago O’Hare VOR/DME | 113.90 MHz, identifier ORD | Bearing and slant-range distance for en-route and terminal navigation. |
| ILS/localiser | Varies by runway and approach | Localiser guidance to the runway centreline, with glideslope where the published procedure is a full ILS. |
| DME associated with an approach | Paired automatically where provided | Distance information used at charted fixes; no separate DME frequency is entered. |
| RNAV (GPS) | No tuneable ground frequency | Uses the aircraft’s navigation database and satellite positioning to fly published fixes and paths. |
There is no single KORD ILS frequency. Each parallel runway—such as 9L, 9C and 9R—has its own published approach, so the runway suffix matters just as much as the runway number. The plate supplies the localiser frequency, identifier, inbound course, altitude constraints and any DME requirement.
Many runway ends also have approach-light systems and visual glide-slope indicators such as PAPI. These help with the visual transition but are not radio aids and cannot be tuned.
Which KORD radio frequencies should pilots use?
Use the arrival or departure ATIS first, then only the clearance, ground, tower or terminal-control frequency assigned for that phase of flight.
| Service | Common KORD frequency | Operational detail |
|---|---|---|
| Arrival ATIS | 135.400 MHz | Arrival runway, weather and airport information. |
| Departure ATIS | 126.750 MHz | Departure runway, weather and relevant airport information. |
| Clearance delivery | 121.600 MHz | IFR clearance and initial departure information. |
| Ground control | 121.750 and 121.900 MHz | Different ground sectors; use the frequency assigned by ATC. |
| O’Hare Tower | 120.750, 126.900 and 132.700 MHz | Split between runway complexes and operating positions. |
| Chicago Approach/Departure | Sector-dependent | Use the frequency printed on the relevant procedure or assigned by ATC. |
O’Hare may also use metering, ramp and operator-specific channels. These do not replace ground control, and pilots should not select one merely because it appears in a simulator’s airport-information window. Our explanation of how to read Chart Supplement frequency and remarks fields covers the abbreviations and restrictions found in official airport listings.
How do I tune a KORD ILS correctly?
Select the plate for the assigned runway before entering any frequency; tuning an ILS for the wrong parallel is a common cause of false or missing guidance.
- Confirm the complete runway designation. Check the number and its L, C or R suffix against the clearance and approach plate.
- Enter the published localiser frequency. Use the NAV receiver or the aircraft’s radio-management system. Many airliners auto-tune from the flight-management system, but the result still needs checking.
- Verify the identifier and front course. Listen for the charted identifier and set the published inbound course if the aircraft requires manual course entry.
- Arm the correct approach mode. The glideslope is paired with the ILS frequency; it is not tuned separately. Follow the aircraft’s intercept and capture procedure.
If the localiser appears but the glideslope does not, confirm that the selected procedure is an ILS rather than a localiser-only approach. Also check the runway end, identifier, serviceability and intercept altitude; attempting to capture from above the glideslope often produces unreliable results.
Why does O’Hare have several tower and ground frequencies?
O’Hare splits radio traffic among controllers because its parallel runway complexes and taxi system are too busy for one tower or ground channel.
The division can change with the runway configuration, staffing and traffic flow. Do not guess the next frequency from the runway alone: remain on the assigned channel until handed off. Our practical O’Hare runway and taxi guide explains how the airport layout affects arrivals, departures and surface movement.
What if KORD charts and the simulator disagree?
A disagreement usually means the chart, aircraft navdata, simulator airport database and scenery represent different revision cycles.
- For real-world operations: the effective authorised chart, applicable NOTAMs and ATC instructions take precedence.
- For built-in simulator ATC: its airport database may expect an older communication frequency, even when a newer chart shows a replacement.
- For online ATC: use the controller’s assigned COM frequency, then verify any instrument procedure against the aircraft’s installed navdata.
- For an ILS or RNAV approach: use a plate and aircraft database that contain the same runway and procedure revision. Do not force an approach that the flight-management system cannot identify correctly.
Scenery, radio navigation data and flight-management data are separate components in many simulators. Updating one does not guarantee that the others represent the same KORD runway layout or procedure set.