| Tail Number / N-Number | N899PS |
| Manufacturer | HESTER WALKER |
| Model | WH4 HARPOON |
| Year Built | 2005 |
| Manufacturer's Serial Number | 0004 |
| Aircraft Type | Fixed wing single engine |
| Category | Land |
| Builder Certification | Not Type Certificated |
| Number of Seats | 4 seats |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Engine Manufacturer | WALTER |
| Engine Model | 601D |
| Engine Type | Turbo-prop |
| Number of Engines | 1 engine |
| Horsepower | 724 hp (540 kW) |
| Type of Registrant | Corporation |
| Owner Name | MODULAR SOLUTIONS INC |
| Street | PO BOX 6115 |
| City | KINSTON |
| State | NC |
| Zip Code | 28501-0115 |
| Region | Eastern |
| County | Lenoir County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Experimental |
| Airworthiness Date | 2005-12-10 |
| Certificate Issue Date | 2016-09-08 |
| Last Action Date | 2022-04-20 |
| Expiration Date | 2029-09-30 |
| Status | Valid Registration |
| Mode S Code | 53064031 |
| Mode S Code Hex | AC6819 |