# N90PK: 1999 Wahl Robert H S-51D

- Status: Valid registration
- Airframe: [Wahl Robert H S-51D](https://openairdocs.org/model/wahl-robert-h-s-51d) (registry code 05607Q4, 2 seats)
- Engine: [Walter 601D](https://openairdocs.org/engine/walter-601d) (registry code 64005)
- Serial number: 149
- Year built: 1999
- Type: Fixed wing single engine
- Engine type: Turbo-prop
- Kit: Stewart 51 Inc S-51D
- Airworthiness: Experimental, amateur built
- Airworthiness date: August 29, 2000
- Certificate issued: September 16, 2004
- Expires: April 30, 2028
- Mode S code: AC6E22
- Registered owner: [Keyes George W](https://openairdocs.org/faa-owner/KEYES%20GEORGE%20W)
- Location: [Flint, TX](https://openairdocs.org/faa-place/TX/Flint)
- Owner type: Individual
- Owner's area on the map: 32.2183° N, 95.4134° W: Placed by OpenAirDocs at the center of ZIP code 75762, 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=90PK
- Page: https://openairdocs.org/aircraft/N90PK

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 (Wahl Robert H S-51D)

None in force.

### Matched by engine (Walter 601D)

None in force.

## Information bulletins (advisory)

None matched.

## NTSB investigations

None matched to N90PK.

## NTSB investigations on N90PK 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 FTW97LA311](https://openairdocs.org/ntsb/FTW97LA311), Aug 12, 1997: Air Tractor AT-402 (N90PK), Patterson, LA, substantial damage. Probable cause: The pilot's failure to maintain terrain clearance.

## FAA accident and incident reports

None matched to N90PK.

## Reports on N90PK not matched to an aircraft (1)

They name N90PK, but no registry record covers the date, the aircraft registered then was built later, or the report describes another aircraft.

- [Accident 19970812022479A](https://openairdocs.org/incident/19970812022479A), Aug 12, 1997: Airtrc AT402 (N90PK), Patterson, LA, Substantial damage. Aircraft struck top of sugar cane while performing aerial application, nosed over into the field, bounced. (-23) while spraying pilot got too low, allowing…

## 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.

## Related

- Other Wahl Robert H S-51D aircraft: https://openairdocs.org/model/wahl-robert-h-s-51d/aircraft.md
- The Walter 601D engine: https://openairdocs.org/engine/walter-601d.md

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