| Tail Number / N-Number | N121U |
| Manufacturer | AERO |
| Model | C-104 |
| Year Built | 1947 |
| Manufacturer's Serial Number | 215 |
| Aircraft Type | Fixed wing single engine |
| Category | Land |
| Builder Certification | Type Certificated |
| Number of Seats | 1 seat |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Engine Manufacturer | SUPERIOR |
| Engine Model | XP-0-360B1AC2 |
| Engine Type | 4 Cycle |
| Number of Engines | 1 engine |
| Horsepower | 180 hp (134 kW) |
| Type of Registrant | Individual |
| Owner Name | SCHAFHAUSEN MARK G |
| Street | 2604 E 62ND LN |
| City | SPOKANE |
| State | WA |
| Zip Code | 99223-6952 |
| Region | Northwest Mountain |
| County | Spokane County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Experimental |
| Airworthiness Date | 2013-07-23 |
| Certificate Issue Date | 1977-02-17 |
| Last Action Date | 2022-07-09 |
| Expiration Date | 2029-08-31 |
| Status | Valid Registration |
| Mode S Code | 50054453 |
| Mode S Code Hex | A0592B |
Deregistered Aircraft 1 of 1. This aircraft was previously assigned the N-number N121U.
| Tail Number / N-Number | N121U |
| Manufacturer | LOCKHEED |
| Model | 188C |
| Year Built | 1959 |
| Manufacturer's Serial Number | 188C1057 |
| Aircraft Type | Fixed wing multi engine |
| Category | Land |
| Builder Certification | Type Certificated |
| Number of Seats | 102 seats |
| Weight Class | CLASS 3 (20,000+ pounds gross take off weight) |
| Number of Engines | 4 engines |
| Average Cruising Speed | 336 miles per hour |
| Type of Registrant | Corporation |
| Owner Name | NORTHWEST AIRLINES INC |
| Street | 1885 UNIVERSITY AVE |
| City | ST PAUL |
| State | MN |
| Zip Code | 55101 |
| Region | Great Lakes |
| County | Spokane County |
| Certificate Issue Date | 1959-09-09 |
| Last Status | Valid Registration |
| Cancellation Date | 1962-11-14 |