| Tail Number / N-Number | N51661 |
| Manufacturer | NEUMANN KENNETH D |
| Model | N-1 |
| Year Built | 2000 |
| Manufacturer's Serial Number | 4534 |
| 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 | CONT MOTOR |
| Engine Model | 0-200 SERIES |
| Engine Type | Reciprocating |
| Number of Engines | 1 engine |
| Horsepower | 100 hp (75 kW) |
| Type of Registrant | Individual |
| Owner Name | HENDERSON TRRY |
| Street | 20 MEADOW WAY |
| City | ROUNDUP |
| State | MT |
| Zip Code | 59072-6826 |
| Region | Northwest Mountain |
| County | Musselshell County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Experimental |
| Airworthiness Date | 2001-06-12 |
| Certificate Issue Date | 2022-03-18 |
| Last Action Date | 2022-03-18 |
| Expiration Date | 2029-03-31 |
| Status | Valid Registration |
| Mode S Code | 51475375 |
| Mode S Code Hex | A67AFD |
Deregistered Aircraft 1 of 1. This aircraft was previously assigned the N-number N51661.
| Tail Number / N-Number | N51661 |
| Manufacturer | ENSTROM |
| Model | F-28C |
| Manufacturer's Serial Number | 398 |
| Aircraft Type | Rotorcraft |
| Category | Land |
| Builder Certification | Type Certificated |
| Number of Seats | 3 seats |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Number of Engines | 1 engine |
| Average Cruising Speed | 75 miles per hour |
| County | Musselshell County |
| Last Status | N-Number Assigned – but has not yet been registered |
| Cancellation Date | 1988-04-26 |