| Navaid Facility ID: | GCO |
| Official Navaid Facility ID: | GCO |
| Navaid Facility Type: | DME |
| Navaid Name: | Chicago |
| City: | CHICAGO |
| State: | ILLINOIS |
| FAA Region: | |
| Latitude: | 41-59-38.720N (41.9941) |
| Longitude: | 087-54-08.380W (-87.9023) |
| Lat/Long Survey Accuracy: | |
| Owner: | FEDERAL AVIATION ADMINISTRATION |
| Operator: | FEDERAL AVIATION ADMINISTRATION |
| Common System Usage: | Yes |
| Public Use: | Yes |
| Navaid Class: | L-DME |
| Hours of Operation: | 24 |
| Magnetic Variance: | 4 W as of 9/30/2025 |
| ARTCC High Altitude ID (Name): | ZAU (CHICAGO) |
| ARTCC Low Altitude ID (Name): | ZAU (CHICAGO) |
| Navaid ID | Navaid Facility Type | Remarks |
|---|---|---|
| GCO | DME | DME UNUSBL 185T-194T BYD 10 NM BLW 4000 FT; 264T-288T BYD 30 NM; 351T-354T BYD 20 NM BLW 4000 FT. |