# N121U: 1947 Aero C-104

- Status: Valid registration
- Airframe: [Aero C-104](https://openairdocs.org/model/aero-c-104) (registry code 1590108, 1 seats)
- Engine: [Superior XP-0-360B1AC2](https://openairdocs.org/engine/superior-xp-0-360b1ac2) (registry code 59261)
- Serial number: 215
- Year built: 1947
- Type: Fixed wing single engine
- Engine type: Reciprocating
- Airworthiness: Experimental, exhibition
- Airworthiness date: July 23, 2013
- Certificate issued: February 17, 1977
- Expires: August 31, 2029
- Mode S code: A0592B
- Registered owner: [Schafhausen Mark G](https://openairdocs.org/faa-owner/SCHAFHAUSEN%20MARK%20G)
- Location: [Spokane, WA](https://openairdocs.org/faa-place/WA/Spokane)
- Owner type: Individual
- Owner's area on the map: 47.5972° N, 117.3178° W: Placed by OpenAirDocs at the center of ZIP code 99223, 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=121U
- Page: https://openairdocs.org/aircraft/N121U

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 (Aero C-104)

None in force.

### Matched by engine (Superior XP-0-360B1AC2)

None in force.

## Information bulletins (advisory)

None matched.

## NTSB investigations

None matched to N121U.

## NTSB investigations on N121U not matched to an aircraft (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 SEA73FYE10](https://openairdocs.org/ntsb/SEA73FYE10), Aug 6, 1972: Bucker Jungmn (N121U), Welcome, WA, substantial damage

## FAA accident and incident reports

None matched to N121U.

## 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 N121U

The FAA can reassign an N-number once a registration is cancelled. These aircraft carried N121U before.

- [Cancelled 1962-11-14](https://openairdocs.org/deregistered/N121U-1962-11-14): Lockheed 188C, S/N 188C1057, built 1959. Owner: [Northwest Airlines Inc](https://openairdocs.org/faa-owner/NORTHWEST%20AIRLINES%20INC), [St Paul, MN](https://openairdocs.org/faa-place/MN/St%20Paul)

## Related

- Other Aero C-104 aircraft: https://openairdocs.org/model/aero-c-104/aircraft.md
- The Superior XP-0-360B1AC2 engine: https://openairdocs.org/engine/superior-xp-0-360b1ac2.md

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