The pilot of the helicopter, Dell Waugh, 69, had been with the Air Angels for three years and was a Purple Heart recipient during the Vietnam War.
The pilot of an Air Angels emergency medical services helicopter has been blamed for a fatal 2008 crash which killed all aboard, including a 14-month-old girl who was being flown to Children's Memorial Hospital in Chicago.
In a report, the National Transportation Safety Board says "inadequate preflight planning" and flying too low, contributed to the incident, where the helicopter struck a radio tower in west suburban Aurora.
The NTSB said pilot Delbert Waugh should have identified any obstacles which would have been in his path as he flew from the chopper's departure airport at Sandwich, Illinois, to Chicago.
In the 11 months between December of 2007 and the Aurora crash, 35 people died in nine medical helicopter crashes nationwide, making 2008 the deadliest year on record.