| Relationships | Role | Relationship Start | Relationship End |
| Helicopter Air Service, Inc. | Parent | 12/31/1977 | 8/18/1978 |
| Helicopter Air Service, Inc. | Parent | 12/31/1970 | 12/30/1977 |
| Polk Bros., Inc. | Parent | 12/31/1970 | 12/30/1976 |
| Mercantile Buildingcorporation | Subsidary | 12/31/1970 | 8/18/1978 |
| Mercantile Safe Deposit Corporation | Subsidary | 12/31/1970 | 8/18/1978 |
| Acquisitions & Mergers | Role | Assets | Acct Method | Type | Transaction Date |
| American National Bank And Trust Company Of Chicago | Buyer | 16,292,607 | Discontinued | 12/8/1979 |