| Tail Number / N-Number | N661X |
| Manufacturer | KNUTSON DAVID J |
| Model | ONEX |
| Year Built | 2015 |
| Manufacturer's Serial Number | ONX0140 |
| 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) |
| Number of Engines | 1 engine |
| Kit Manufacturer | SONEX AIRCRAFT LLC |
| Kit Model | ONEX |
| Type of Registrant | Individual |
| Owner Name | KNUTSON DAVID J |
| Street | 36016 SE 49TH ST |
| City | FALL CITY |
| State | WA |
| Zip Code | 98024-9714 |
| Region | Northwest Mountain |
| County | King County |
| Country | US |
| Fractional Ownership | No |
| Certificate Issue Date | 2015-03-18 |
| Last Action Date | 2020-10-14 |
| Expiration Date | 2028-03-31 |
| Status | Valid Registration |
| Mode S Code | 52134775 |
| Mode S Code Hex | A8B9FD |
Deregistered Aircraft 1 of 1. This aircraft was previously assigned the N-number N661X.
| Tail Number / N-Number | N661X |
| Manufacturer | SCHEMPP-HIRTH |
| Model | VENTUS-B |
| Year Built | 1982 |
| Manufacturer's Serial Number | 79 |
| Aircraft Type | Glider |
| 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 | NONE |
| Engine Model | NONE |
| Number of Engines | 0 engines |
| Type of Registrant | Individual |
| Owner Name | SMOLDER CLEMENT A II |
| Street | 17223 N 31ST DR |
| City | PHOENIX |
| State | AZ |
| Zip Code | 85023 |
| County | King County |
| Country | US |
| Airworthiness Classification | Experimental |
| Airworthiness Date | 1982-06-23 |
| Certificate Issue Date | 1995-06-05 |
| Last Action Date | 2004-05-18 |
| Last Status | The Triennial Aircraft Registration form was mailed and has not been returned by the Post Office |
| Cancellation Date | 2005-03-17 |
| Exported To | AUSTRALIA |