# N123SX: Monnett John T JR SONEX SA, registration cancelled 2015-10-05

- Type: Cancelled registration (FAA registry, deregistered aircraft)
- Cancelled: October 5, 2015
- Status when cancelled: Valid registration
- Airframe: [Monnett John T JR SONEX SA](https://openairdocs.org/model/monnett-john-t-jr-sonex-sa) (registry code 056220I)
- Serial number: 0008
- Type of aircraft: Fixed wing single engine
- Kit: Sonex Aircraft LLC SONEX
- Certificate issued: July 16, 2007
- Last registry action: August 13, 2014
- Mode S code: A0607D
- Owner when cancelled: [Sonex Aircraft LLC](https://openairdocs.org/faa-owner/SONEX%20AIRCRAFT%20LLC)
- Location: [Oshkosh, WI](https://openairdocs.org/faa-place/WI/Oshkosh)
- Owner type: Corporation
- Owner's area on the map: 43.9441° N, 88.5348° W: Placed by OpenAirDocs at the center of ZIP code 54902, within about 3 miles (OpenAirDocs). The owner's mailing address, not where the aircraft was based
- The mark today: https://openairdocs.org/aircraft/N123SX
- FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=123SX
- Page: https://openairdocs.org/deregistered/N123SX-2015-10-05

From the FAA registry file of November 3, 2026, cancelled registrations. Owners' street addresses are left out. The Mode S code belongs to the N-number, not the airframe.

ADs and bulletins for the Monnett John T JR SONEX SA: https://openairdocs.org/model/monnett-john-t-jr-sonex-sa.md

## NTSB investigations (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB CEN15FA249](https://openairdocs.org/ntsb/CEN15FA249), Jun 2, 2015: Monnett John T JR Sonex SA (N123SX), Oshkosh, WI, substantial damage, 2 fatal. Probable cause: The pilot's failure to maintain sufficient airspeed following a loss of engine power during initial takeoff climb, which resulted in the airplane's wing exceeding its critical angle-of-attack and a…

## FAA accident and incident reports (1)

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [Accident 20150602007549A](https://openairdocs.org/incident/20150602007549A), Jun 2, 2015: Monnett John T Jr SONEX SA (N123SX), Oshkosh, WI, Destroyed, 2 fatal. On June 2, 2015, at 1515 dst an amateur built Sonex Sa N123SX experienced loss of engine power. The aircraft landed short of runway 27 Oshkosh, WI. Colliding…

## Other aircraft with N123SX

- [Registered now](https://openairdocs.org/aircraft/N123SX): Air Fly Balonisimo E Inflaveis AF-SS-40, S/N LP2018-02, built 2018

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