# N661X: 2015 Knutson David J ONEX

- Status: Valid registration
- Airframe: [Knutson David J ONEX](https://openairdocs.org/model/knutson-david-j-onex) (registry code 056335O, 1 seats)
- Serial number: ONX0140
- Year built: 2015
- Type: Fixed wing single engine
- Engine type: Reciprocating
- Kit: Sonex Aircraft LLC ONEX
- Certificate issued: March 18, 2015
- Expires: March 31, 2028
- Mode S code: A8B9FD
- Registered owner: [Knutson David J](https://openairdocs.org/faa-owner/KNUTSON%20DAVID%20J)
- Location: [Fall City, WA](https://openairdocs.org/faa-place/WA/Fall%20City)
- Owner type: Individual
- Owner's area on the map: 47.5734° N, 121.8992° W: Placed by OpenAirDocs at the center of ZIP code 98024, within about 3 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based
- FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=661X
- Page: https://openairdocs.org/aircraft/N661X

From the FAA registry file of October 24, 2026. ADs below are matched by the registry's airframe and engine model codes. They may apply; each AD's applicability can narrow it by serial number, part number or installed equipment. This is not a compliance determination.

## ADs that may apply (OpenAirDocs): 0 in force

### Matched by airframe (Knutson David J ONEX)

None in force.

## Information bulletins (advisory)

None matched.

## NTSB investigations

None matched to N661X.

## FAA accident and incident reports

None matched to N661X.

## Service difficulty reports

None filed for this aircraft. Matched to this aircraft by N-number and event date, checked against the reported serial number, make and model.

## STCs that may be installed (OpenAirDocs)

None matched to this aircraft's models.

## Earlier aircraft with N661X

The FAA can reassign an N-number once a registration is cancelled. These aircraft carried N661X before.

- [Cancelled 2005-03-17](https://openairdocs.org/deregistered/N661X-2005-03-17): Schempp-Hirth VENTUS-B, S/N 79, built 1982. Exported to Australia. Owner: [Smolder Clement A II](https://openairdocs.org/faa-owner/SMOLDER%20CLEMENT%20A%20II), [Phoenix, AZ](https://openairdocs.org/faa-place/AZ/Phoenix)

## Related

- Other Knutson David J ONEX aircraft: https://openairdocs.org/model/knutson-david-j-onex/aircraft.md

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.