# N781EX: 2025 Ferstl Mark R ONEX

- Status: Valid registration
- Airframe: [Ferstl Mark R ONEX](https://openairdocs.org/model/ferstl-mark-r-onex) (registry code 056425U, 1 seats)
- Engine: [Rotax 912ULS](https://openairdocs.org/engine/rotax-912uls) (registry code 55607)
- Serial number: ONX 0040
- Year built: 2025
- Type: Fixed wing single engine
- Engine type: Reciprocating
- Kit: Sonex Aircraft LLC ONEX
- Airworthiness: Experimental, amateur built
- Airworthiness date: August 27, 2025
- Certificate issued: May 19, 2025
- Expires: May 31, 2032
- Mode S code: AA94B7
- Registered owner: [Ferstl Mark R](https://openairdocs.org/faa-owner/FERSTL%20MARK%20R)
- Location: [Tucson, AZ](https://openairdocs.org/faa-place/AZ/Tucson)
- Owner type: Individual
- Owner's area on the map: 32.2150° N, 110.8835° W: Placed by OpenAirDocs at the center of ZIP code 85711, within about 2 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based
- FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=781EX
- Page: https://openairdocs.org/aircraft/N781EX

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 (Ferstl Mark R ONEX)

None in force.

### Matched by engine (Rotax 912ULS)

None in force.

## Information bulletins (advisory)

None matched.

## NTSB investigations

None matched to N781EX.

## FAA accident and incident reports

None matched to N781EX.

## 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 N781EX

The FAA can reassign an N-number once a registration is cancelled. These aircraft carried N781EX before.

- [Cancelled 2010-09-07](https://openairdocs.org/deregistered/N781EX-2010-09-07): Dassault FALCON 2000EX, S/N 187, built 2009. Exported to Brazil. Owner: [Dassault Falcon Jet Corp](https://openairdocs.org/faa-owner/DASSAULT%20FALCON%20JET%20CORP), [Little Ferry, NJ](https://openairdocs.org/faa-place/NJ/Little%20Ferry)

## Related

- Other Ferstl Mark R ONEX aircraft: https://openairdocs.org/model/ferstl-mark-r-onex/aircraft.md
- The Rotax 912ULS engine: https://openairdocs.org/engine/rotax-912uls.md

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