| Tail Number / N-Number | N721WC |
| Manufacturer | ALEXANDER SCHLEICHER GMBH & CO |
| Model | ASK 21 |
| Year Built | 1997 |
| Manufacturer's Serial Number | 21650 |
| Aircraft Type | Glider |
| Category | Land |
| Builder Certification | Not 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 |
| 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 | 2008-04-22 |
| Certificate Issue Date | 2008-01-17 |
| Last Action Date | 2021-12-24 |
| Expiration Date | 2029-05-31 |
| Status | Valid Registration |
| Mode S Code | 52324472 |
| Mode S Code Hex | A9A93A |