| Tail Number / N-Number | N121WC |
| Manufacturer | SCHLEICHER |
| Model | ASK-21 |
| Year Built | 1990 |
| Manufacturer's Serial Number | 21464 |
| Aircraft Type | Glider |
| Category | Land |
| Builder Certification | Type Certificated |
| Number of Seats | 2 seats |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Engine Manufacturer | NONE |
| Engine Model | NONE |
| Number of Engines | 0 engines |
| Type of Registrant | Corporation |
| Owner Name | WINDY CITY SOARING ASSOCIATION INC |
| Street | PO BOX 868 |
| City | HINCKLEY |
| State | IL |
| Zip Code | 60520-0868 |
| Region | Great Lakes |
| County | DeKalb County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Standard |
| Airworthiness Date | 2003-03-03 |
| Certificate Issue Date | 2003-01-22 |
| Last Action Date | 2021-11-13 |
| Expiration Date | 2029-04-30 |
| Status | Valid Registration |
| Mode S Code | 50054540 |
| Mode S Code Hex | A05960 |