| Tail Number / N-Number | N111SF |
| Manufacturer | WILLIAMS JOHN J |
| Model | WILLIAMS CX4 |
| Year Built | 2021 |
| Manufacturer's Serial Number | 146-X |
| Aircraft Type | Fixed wing single engine |
| Category | Land |
| Builder Certification | Not Type Certificated |
| Number of Seats | 1 seat |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Engine Manufacturer | REVMASTER |
| Engine Model | 2100D |
| Engine Type | Reciprocating |
| Number of Engines | 1 engine |
| Horsepower | 65 hp (48 kW) |
| Type of Registrant | Individual |
| Owner Name | WILLIAMS JOHN J |
| Street | 1028 COUNTY STREET 2939 |
| City | TUTTLE |
| State | OK |
| Zip Code | 73089-3034 |
| Region | Southwestern |
| County | Grady County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Experimental |
| Airworthiness Date | 2021-11-15 |
| Certificate Issue Date | 2020-12-07 |
| Last Action Date | 2020-12-07 |
| Expiration Date | 2027-12-31 |
| Status | Valid Registration |
| Mode S Code | 50030600 |
| Mode S Code Hex | A03180 |