| Tail Number / N-Number | N9WK |
| Manufacturer | KASTENHOLZ WILLIAM G |
| Model | COZY MARK IV |
| Year Built | 2003 |
| Manufacturer's Serial Number | 0536 |
| Aircraft Type | Fixed wing single engine |
| Category | Land |
| Builder Certification | Not Type Certificated |
| Number of Seats | 4 seats |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Engine Manufacturer | LYCOMING |
| Engine Model | O-360 SERIES |
| Engine Type | Reciprocating |
| Number of Engines | 1 engine |
| Horsepower | 180 hp (134 kW) |
| Type of Registrant | Individual |
| Owner Name | KASTENHOLZ WILLIAM G |
| Street | 1237 TWIN PEAKS CIR |
| City | LONGMONT |
| State | CO |
| Zip Code | 80503-2171 |
| Region | Northwest Mountain |
| County | Boulder County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Experimental |
| Airworthiness Date | 2003-10-20 |
| Certificate Issue Date | 2003-05-16 |
| Last Action Date | 2023-01-22 |
| Expiration Date | 2027-05-31 |
| Status | Valid Registration |
| Mode S Code | 53066170 |
| Mode S Code Hex | AC6C78 |
Deregistered Aircraft 1 of 1. This aircraft was previously assigned the N-number N9WK.
| Tail Number / N-Number | N9WK |
| Manufacturer | AEROTEK |
| Model | PITTS S-2A |
| Manufacturer's Serial Number | 2009 |
| Aircraft Type | Fixed wing single engine |
| Category | Land |
| Builder Certification | Type Certificated |
| Number of Seats | 2 seats |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Number of Engines | 1 engine |
| Average Cruising Speed | 115 miles per hour |
| Type of Registrant | Individual |
| Owner Name | GRIEB LINN D |
| Street | 4001 NASA ONE 307 |
| City | SEABROOK |
| State | TX |
| Zip Code | 77586 |
| County | Boulder County |
| Country | US |
| Certificate Issue Date | 1991-03-01 |
| Last Action Date | 1994-03-20 |
| Last Status | The Triennial Aircraft Registration form was mailed and has not been returned by the Post Office |
| Cancellation Date | 1997-01-16 |
| Exported To | SPAIN |