**Exhibit      21.1**

**Subsidiaries      of the Registrant**

| **Subsidiary                Name**                                                                                   | **State                of Incorporation/Formation** |
|----------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------|
| Macquarie                  Infrastructure Company Inc.(d/b/a Macquarie Infrastructure Company                  (US)) | Delaware                                            |
| Macquarie                Yorkshire LLC                                                                               | Delaware                                            |
| Communications                Infrastructure LLC                                                                     | Delaware                                            |
| South                East Water LLC                                                                                  | Delaware                                            |
| Atlantic                Aviation FBO Holdings LLC (fka                Macquarie FBO Holdings LLC)                    | Delaware                                            |
| MIC                European Financing Sarl                                                                           | Luxembourg                                          |
| Macquarie                District Energy Holdings LLC                                                                | Delaware                                            |
| Macquarie                Americas Parking Corporation                                                                | Delaware                                            |
| Macquarie                Gas Holdings LLC                                                                            | Delaware                                            |
| Macquarie                Terminal Holdings LLC                                                                       | Delaware                                            |
| Futura                Natural Gas LLC                                                                                | Delaware                                            |
| Seacoast                Holdings (PCAAH), Inc.                                                                       | Delaware                                            |
| Atlantic                Aviation FBO, Inc. (fka                North America Capital Holding Company)                | Delaware                                            |
| Mercury                Air Centers, Inc.                                                                             | Delaware                                            |
| Rifle                Air, LLC                                                                                        | Colorado                                            |
| Eagle                Aviation Resources, Ltd.                                                                        | Nevada                                              |
| Macquarie                Airports North America Inc.                                                                 | Delaware                                            |
| Macquarie                Aviation North America Inc.                                                                 | Delaware                                            |
| Macquarie                Aviation North America 2 Inc.                                                               | Delaware                                            |
| Trajen                Holdings, Inc.                                                                                 | Delaware                                            |
| ILG                Avcenter, Inc.                                                                                    | Delaware                                            |
| BTV                Avcenter, Inc.:                                                                                   | Delaware                                            |
| Atlantic                Aviation Holding Corporation                                                                 | Delaware                                            |
| Atlantic                Aviation Corporation                                                                         | Delaware                                            |
| Atlantic                Aviation Flight Support, Inc.                                                                | Delaware                                            |
| Bridgeport                Airport Services, Inc                                                                      | Connecticut                                         |
| Atlantic                Aviation Philadelphia, Inc.                                                                  | Delaware                                            |
| COAI                Holdings, LLC                                                                                    | Delaware                                            |
| Charter                Oak Aviation, Inc.                                                                            | Connecticut                                         |
| BASI                Holdings, LLC                                                                                    | Delaware                                            |
| Brainard                Airport Services, Inc                                                                        | Connecticut                                         |
| AAC                Subsidiary, LLC                                                                                   | Delaware                                            |
| Executive                Air Support, Inc                                                                            | Delaware                                            |
| Flightways                of Long Island Inc. (d/b/a                Million Air)                                     | New                York                             |
| FLI                Subsidiary, LLC                                                                                   | Delaware                                            |
| General                Aviation, LLC                                                                                 | Louisiana                                           |
| General                Aviation of New Orleans, LLC                                                                  | Louisiana                                           |
| General                Aviation Holdings LLC                                                                         | Delaware                                            |
| Newport                FBO Two LLC                                                                                   | Delaware                                            |
| Palm                Springs FBO Two, LLC                                                                             | Delaware                                            |
| Trajen                Funding, Inc.                                                                                  | Delaware                                            |
| Trajen                Limited, LLC                                                                                   | Delaware                                            |
| Trajen                FBO, LLC                                                                                       | Delaware                                            |
| Trajen                Flight Support, LP                                                                             | Delaware                                            |
| Waukesha                Flying Services, Inc.                                                                        | Wisconsin                                           |
| Sierra                Aviation, Inc.                                                                                 | Oklahoma                                            |
| Atlantic                SMO Holdings LLC                                                                             | Delaware                                            |
| Atlantic                SMO GP LLC                                                                                   | Delaware                                            |
| ProAir                Aviation Maintenance, LLC                                                                      | Delaware                                            |
| Supermarine                of Stewart LLC                                                                            | Delaware                                            |
| Aviation                Contract Services, Inc                                                                       | California                                          |
| Supermarine                Investors, Inc.                                                                           | California                                          |
| Supermarine                of Santa Monica, a California Limited Partnership                                         | California                                          |
| Mercury                Air Center-Burbank, Inc.                                                                      | California                                          |
| Corporate                Wings-CGF, LLC                                                                              | Ohio                                                |
| Mercury                Air Center-Johns Island, LLC                                                                  | South                Carolina                       |
| Mercury                Air Center-Nashville, LLC                                                                     | Delaware                                            |
| Mercury                Air Center-Peachtree-Dekalb, LLC                                                              | Georgia                                             |
| SBN,                Inc.                                                                                             | Indiana                                             |
| Mercury                Air Center-Charleston, LLC                                                                    | South                Carolina                       |
| Mercury                Air Center-Jackson, LLC                                                                       | Mississippi                                         |
| Mercury                Air Center-Los Angeles, Inc.                                                                  | California                                          |
| Mercury                Air Center-Newport News, LLC                                                                  | Virginia                                            |
| Mercury                Air Center-Santa Barbara, Inc.                                                                | California                                          |
| Corporate                Wings-Hopkins, LLC                                                                          | Ohio                                                |
| Mercury                Air Center-Addison, Inc.                                                                      | Texas                                               |
| Mercury                Air Center-Birmingham, LLC                                                                    | Alabama                                             |
| Mercury                Air Center-Bakersfield, Inc.                                                                  | California                                          |
| Mercury                Air Center-Corpus Christi, Inc.                                                               | Texas                                               |
| Mercury                Air Center-Fort Wayne, LLC                                                                    | Indiana                                             |
| Mercury                Air Center-Hartsfield, LLC                                                                    | Georgia                                             |
| Mercury                Air Center-Fresno, Inc.                                                                       | California                                          |
| Mercury                Air Center-Ontario, Inc.                                                                      | California                                          |
| Mercury                Air Center-Reno, LLC                                                                          | Nevada                                              |
| Mercury                Air Center-Tulsa, LLC                                                                         | Oklahoma                                            |
| Mercury                Air Center-Hopkins, LLC                                                                       | Ohio                                                |
| MAC                Acquisitions LLC                                                                                  | Delaware                                            |
| JetSouth                LLC                                                                                          | Alabama                                             |
| SJJC                Aviation Services, LLC                                                                           | Delaware                                            |
| SJJC                FBO Services, LLC                                                                                | Delaware                                            |
| SJJC                Airline Services, LLC                                                                            | Delaware                                            |
| Jet                Center Property Services, LLC                                                                     | Delaware                                            |
| ACM                Property Services, LLC                                                                            | Delaware                                            |
| ACM                Aviation, LLC                                                                                     | Delaware                                            |
| Rifle                Jet Center, LLC                                                                                 | Colorado                                            |
| Rifle                Jet Center Maintenance, LLC                                                                     | Colorado                                            |
| Parking                Company of America Airports Holdings, LLC                                                     | Delaware                                            |
| PCAA                Parent, LLC                                                                                      | Delaware                                            |
| RCL                Properties, LLC                                                                                   | Pennsylvania                                        |
| PCAA                Properties, LLC                                                                                  | Delaware                                            |
| PCAA                Oakland, LLC(fka PCAA Chicago Holdings, LLC)                                                     | Delaware                                            |
| Parking                Company of America Airports, LLC                                                              | Delaware                                            |
| PCAA                GP, LLC                                                                                          | Delaware                                            |
| PCAA                LP, LLC                                                                                          | Delaware                                            |
| PCA                Airports, Ltd.                                                                                    | Texas                                               |
| Parking                Company of America Airports Phoenix, LLC                                                      | Delaware                                            |
| PCAA                Chicago, LLC                                                                                     | Delaware                                            |
| Airport                Parking Management, LLC (fka                Airport Parking Management Inc.)                  | Delaware                                            |
| PCAA                Missouri, LLC                                                                                    | Delaware                                            |
| PCAA                SP, LLC                                                                                          | Delaware                                            |
| PCAA                SP-OK, LLC                                                                                       | Delaware                                            |
| Macquarie                HGC Investment LLC                                                                          | Hawaii                                              |
| HGC                Investment Corporation                                                                            | Delaware                                            |
| HGC                Holdings LLC                                                                                      | Hawaii                                              |
| The                Gas Company LLC                                                                                   | Hawaii                                              |
| Macquarie                District Energy Inc.                                                                        | Delaware                                            |
| Thermal                Chicago Corporation                                                                           | Delaware                                            |
| MDE                Thermal Technologies Inc.                                                                         | Illinois                                            |
| Northwind                Chicago LLC                                                                                 | Delaware                                            |
| ETT                National Power, Inc.                                                                              | Illinois                                            |
| Northwind                Midway LLC                                                                                  | Delaware                                            |
| ETT                Nevada, Inc.                                                                                      | Nevada                                              |
| Northwind                Aladdin LLC                                                                                 | Nevada                                              |

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