# N421MM: 1974 Cessna 421B, registration cancelled 2021-03-17

- Type: Cancelled registration (FAA registry, deregistered aircraft)
- Cancelled: March 17, 2021
- Status when cancelled: Registration expired
- Airframe: [Cessna 421B](https://openairdocs.org/model/cessna-421b) (registry code 2076014)
- Engine: [Continental GTSIO-520-C](https://openairdocs.org/engine/continental-gtsio-520-c) (registry code 17035)
- Data sheets: [TCDS A7CE](https://openairdocs.org/tcds/A7CE), [TCDS E7CE](https://openairdocs.org/tcds/E7CE) (OpenAirDocs)
- Serial number: 421B0804
- Year built: 1974
- Type of aircraft: Fixed wing multi engine
- Engine type: Reciprocating
- Airworthiness: Standard, normal
- Airworthiness date: October 21, 1974
- Certificate issued: February 6, 2018
- Last registry action: February 6, 2018
- Mode S code: A50075
- Owner when cancelled: [Hat Investments LLC](https://openairdocs.org/faa-owner/HAT%20INVESTMENTS%20LLC)
- Location: [Spartanburg, SC](https://openairdocs.org/faa-place/SC/Spartanburg)
- Owner type: LLC
- Owner's area on the map: 34.9980° N, 81.9673° W: Placed by OpenAirDocs at the center of ZIP code 29303, within about 3 miles (OpenAirDocs). The owner's mailing address, not where the aircraft was based
- The mark today: https://openairdocs.org/aircraft/N421MM
- FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=421MM
- Page: https://openairdocs.org/deregistered/N421MM-2021-03-17

From the FAA registry file of October 29, 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 Cessna 421B: https://openairdocs.org/model/cessna-421b.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 ERA18WA159](https://openairdocs.org/ntsb/ERA18WA159), Jun 5, 2018: Cessna 421B (N421MM), Rock Sound, Bahamas, destroyed, 3 fatal

## 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.

- [Incident 19930817037219I](https://openairdocs.org/incident/19930817037219I), Aug 17, 1993: Cessna 421B (N421MM), East Hampton, NY, Minor damage. On liftoff, nose gear hit a deer. Continued to newark. Nose gear collapsed on landing rollout.

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