# N421MK: Keppel Merritt GT500

- Status: Valid registration
- Airframe: [Keppel Merritt GT500](https://openairdocs.org/model/keppel-merritt-gt500) (registry code 05623YL, 2 seats)
- Serial number: 0163
- Type: Fixed wing single engine
- Engine type: Reciprocating
- Certificate issued: September 2, 1993
- Expires: September 30, 2028
- Mode S code: A50073
- Registered owners: [Keppel Merritt Ta](https://openairdocs.org/faa-owner/KEPPEL%20MERRITT%20TA), [Mk Enterprises](https://openairdocs.org/faa-owner/MK%20ENTERPRISES)
- Location: [Ford, VA](https://openairdocs.org/faa-place/VA/Ford)
- Owner type: Individual
- Owner's area on the map: 37.1592° N, 77.7386° W: Placed by OpenAirDocs at the center of ZIP code 23850, within about 4 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based
- FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=421MK
- Page: https://openairdocs.org/aircraft/N421MK

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 (Keppel Merritt GT500)

None in force.

## Information bulletins (advisory)

None matched.

## NTSB investigations

None matched to N421MK.

## FAA accident and incident reports

None matched to N421MK.

## 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.

## Service difficulty reports on N421MK not matched to an aircraft (1)

They name N421MK, but no registry record covers the date, the aircraft registered then was built later, or the report describes another aircraft.

- [SDR 20000712SH007](https://openairdocs.org/sdr/20000712SH007), Apr 4, 2000: DRIVE SHAFT. CORRODED. SUSPECTED CORROSION ON SHAFT TUBE AREA, BLISTERING. REPLACED SHAFT WITH A NEW UNIT IAW SIKORSKY MM. (X)

## STCs that may be installed (OpenAirDocs)

None matched to this aircraft's models.

## Related

- Other Keppel Merritt GT500 aircraft: https://openairdocs.org/model/keppel-merritt-gt500/aircraft.md

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