| Tail Number / N-Number | N399KK |
| Manufacturer | SIKORSKY |
| Model | S-76C |
| Year Built | 2003 |
| Manufacturer's Serial Number | 760550 |
| Aircraft Type | Rotorcraft |
| Category | Land |
| Builder Certification | Type Certificated |
| Number of Seats | 14 seats |
| Weight Class | CLASS 1 (Up to 12,499 pounds gross take off weight) |
| Engine Manufacturer | TURBOMECA |
| Engine Model | ARRIEL 2S1 |
| Engine Type | Turbo-shaft |
| Number of Engines | 2 engines |
| Horsepower per Engine | 833 hp (621 kW) |
| Total Horsepower | 1,666 hp (1,243 kW) |
| Type of Registrant | Corporation |
| Owner Name | CITIGROUP INC |
| Street | 79 TOWER RD HGR E-2 |
| City | WEST HARRISON |
| State | NY |
| Zip Code | 10604 |
| Region | Eastern |
| County | Westchester County |
| Country | US |
| Fractional Ownership | No |
| Airworthiness Classification | Standard |
| Airworthiness Date | 2006-03-28 |
| Certificate Issue Date | 2016-07-05 |
| Last Action Date | 2022-02-28 |
| Expiration Date | 2029-07-31 |
| Status | Valid Registration |
| Mode S Code | 51122443 |
| Mode S Code Hex | A4A523 |