| Tail Number / N-Number | N21108 |
| Manufacturer | BOEING |
| Model | 757-224 |
| Year Built | 1994 |
| Manufacturer's Serial Number | 27298 |
| Aircraft Type | Fixed wing multi engine |
| Category | Land |
| Builder Certification | Type Certificated |
| Number of Seats | 178 seats |
| Weight Class | CLASS 3 (20,000+ pounds gross take off weight) |
| Engine Manufacturer | ROLLS-ROYC |
| Engine Model | RB-211 SERIES |
| Engine Type | Turbo-fan |
| Number of Engines | 2 engines |
| Thrust per Engine | 22,000 pounds-force (97.9 kN) |
| Total Thrust | 44,000 pounds-force (195.7 kN) |
| Type of Registrant | Corporation |
| Owner Name | UNITED AIRLINES INC |
| Street | 233 S WACKER DR |
| City | CHICAGO |
| State | IL |
| Zip Code | 60606-7147 |
| Region | Great Lakes |
| County | Cook County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Standard |
| Airworthiness Date | 1994-11-07 |
| Certificate Issue Date | 2014-07-15 |
| Last Action Date | 2020-06-18 |
| Expiration Date | 2027-07-31 |
| Status | Valid Registration |
| Mode S Code | 50337662 |
| Mode S Code Hex | A1BFB2 |