| Tail Number / N-Number | N921UM |
| Manufacturer | MIKOYAN GUREVICH |
| Model | MIG 21 UM |
| Manufacturer's Serial Number | 516979001 |
| Aircraft Type | Fixed wing single engine |
| Category | Land |
| Builder Certification | Not Type Certificated |
| Number of Seats | 1 seat |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Number of Engines | 1 engine |
| Type of Registrant | LLC |
| Owner Name | L-29 HOLDINGS LLC |
| Street | 157 PEMBERTON LOOP |
| City | FAIRHOPE |
| State | AL |
| Zip Code | 36532-7068 |
| Region | Southern |
| County | Baldwin County |
| Country | US |
| Fractional Ownership | No |
| Certificate Issue Date | 2018-11-27 |
| Last Action Date | 2021-07-29 |
| Expiration Date | 2028-11-30 |
| Status | Valid Registration |
| Mode S Code | 53141657 |
| Mode S Code Hex | ACC3AF |