| Tail Number / N-Number | N551MM |
| Manufacturer | AIRBUS HELICOPTERS |
| Model | EC 130 T2 |
| Manufacturer's Serial Number | 8379 |
| Aircraft Type | Rotorcraft |
| Category | Land |
| Builder Certification | Type Certificated |
| Number of Seats | 8 seats |
| Weight Class | CLASS 2 (12,500 - 19,999 pounds gross take off weight) |
| Number of Engines | 1 engine |
| Type of Registrant | LLC |
| Owner Name | HELICOPTER HOLDINGS LLC |
| Street | 10000 MARQUIS DR |
| City | HENNEPIN |
| State | IL |
| Zip Code | 61327-1000 |
| Region | Great Lakes |
| County | Putnam County |
| Country | US |
| Fractional Ownership | No |
| Certificate Issue Date | 2020-04-02 |
| Last Action Date | 2023-02-07 |
| Expiration Date | 2027-04-30 |
| Status | Valid Registration |
| Mode S Code | 51602101 |
| Mode S Code Hex | A70441 |
Deregistered Aircraft 1 of 1. This aircraft was previously assigned the N-number N551MM.
| Tail Number / N-Number | N551MM |
| Manufacturer | AGUSTA SPA |
| Model | A109E |
| Year Built | 1997 |
| Manufacturer's Serial Number | 11011 |
| Aircraft Type | Rotorcraft |
| 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 | P&W CANADA |
| Engine Model | PW206C |
| Engine Type | Turbo-shaft |
| Number of Engines | 2 engines |
| Horsepower per Engine | 561 hp (419 kW) |
| Total Horsepower | 1,122 hp (837 kW) |
| Type of Registrant | Corporation |
| Owner Name | CASTLE HELICOPTERS INC |
| Street | 1220 N MARKET ST STE 808 |
| City | WILMINGTON |
| State | DE |
| Zip Code | 19801-2595 |
| County | Putnam County |
| Country | US |
| Airworthiness Classification | Standard |
| Airworthiness Date | 2007-04-24 |
| Certificate Issue Date | 2009-09-21 |
| Last Action Date | 2009-09-21 |
| Last Status | Valid Registration |
| Cancellation Date | 2009-10-14 |
| Exported To | UNITED KINGDOM |