| Tail Number / N-Number | N531X |
| Manufacturer | FOSTER DUDLEY B |
| Model | ONEX |
| Year Built | 2014 |
| Manufacturer's Serial Number | ONX0054 |
| 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 | AEROVEE |
| Engine Model | 2.1 |
| Engine Type | 4 Cycle |
| Number of Engines | 1 engine |
| Horsepower | 80 hp (60 kW) |
| Kit Manufacturer | SONEX AIRCRAFT LLC |
| Kit Model | ONEX |
| Type of Registrant | Individual |
| Owner Name | FOSTER DUDLEY B |
| Street | 19 JOSHUA LN |
| City | EAST FALMOUTH |
| State | MA |
| Zip Code | 02536-5483 |
| Region | New England |
| County | Barnstable County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Experimental |
| Airworthiness Date | 2014-02-22 |
| Certificate Issue Date | 2014-01-13 |
| Last Action Date | 2022-08-18 |
| Expiration Date | 2030-01-31 |
| Status | Valid Registration |
| Mode S Code | 51533061 |
| Mode S Code Hex | A6B631 |