| Tail Number / N-Number | N123SM |
| Manufacturer | CESSNA |
| Model | 421 |
| Year Built | 1968 |
| Manufacturer's Serial Number | 421-0193 |
| Aircraft Type | Fixed wing multi engine |
| Category | Land |
| Builder Certification | Type Certificated |
| Number of Seats | 8 seats |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Engine Manufacturer | CONT MOTOR |
| Engine Model | GTSIO-520-C |
| Engine Type | Reciprocating |
| Number of Engines | 2 engines |
| Horsepower per Engine | 340 hp (254 kW) |
| Total Horsepower | 680 hp (507 kW) |
| Average Cruising Speed | 172 miles per hour |
| Type of Registrant | LLC |
| Owner Name | FERNAIR LLC |
| Street | 4930 ELLA BLVD |
| City | HOUSTON |
| State | TX |
| Zip Code | 77018-1926 |
| Region | Southwestern |
| County | Harris County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Standard |
| Airworthiness Date | 1968-12-31 |
| Certificate Issue Date | 2019-01-02 |
| Last Action Date | 2022-03-01 |
| Expiration Date | 2029-01-31 |
| Status | Valid Registration |
| Mode S Code | 50060163 |
| Mode S Code Hex | A06073 |