| Tail Number / N-Number | N139WS |
| Manufacturer | AERO VODOCHODY |
| Model | L39C |
| Year Built | 1984 |
| Manufacturer's Serial Number | 432931 |
| 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 | IVCHENKO |
| Engine Model | AI-25TL |
| Engine Type | Turbo-fan |
| Number of Engines | 1 engine |
| Thrust | 3,792 pounds-force (16.9 kN) |
| Type of Registrant | Corporation |
| Owner Name | NATIONAL TEST PILOT SCHOOL |
| Street | 1030 FLIGHT LINE STE 72 |
| City | MOJAVE |
| State | CA |
| Zip Code | 93501-1679 |
| Region | Western-Pacific |
| County | Kern County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Experimental |
| Airworthiness Date | 2018-04-21 |
| Certificate Issue Date | 2015-10-28 |
| Last Action Date | 2021-05-17 |
| Expiration Date | 2028-10-31 |
| Status | Valid Registration |
| Mode S Code | 50117245 |
| Mode S Code Hex | A09EA5 |