| Tail Number / N-Number | N121VT |
| Manufacturer | WILLIAMS RALPH J |
| Model | WITTMAN TAILWIND |
| Year Built | 2007 |
| Manufacturer's Serial Number | 99-1131 |
| Aircraft Type | Fixed wing single engine |
| 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 | LYCOMING |
| Engine Model | O-320-E2A |
| Engine Type | 4 Cycle |
| Number of Engines | 1 engine |
| Horsepower | 150 hp (112 kW) |
| Type of Registrant | Individual |
| Owner Name | WILLIAMS RALPH J |
| Street | 9 HANLEY LN |
| City | ESSEX JUNCTION |
| State | VT |
| Zip Code | 05452-2308 |
| Region | New England |
| County | Chittenden County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Experimental |
| Airworthiness Date | 2008-01-31 |
| Certificate Issue Date | 2007-09-07 |
| Last Action Date | 2021-03-27 |
| Expiration Date | 2028-04-30 |
| Status | Valid Registration |
| Mode S Code | 50054526 |
| Mode S Code Hex | A05956 |