Flight 4873 · Embraer EMB-135

As the airplane was being pushed out from the gate area, with only one wing walker positioned off of the right wing, the left wing and a refuse truck collided. There was no communication established between the tug operator, and the cockpit crew due to the lack of interphone headsets. The refuse truck operator stated he positioned the refuse truck behind the left side of the airplane to allow an assistant to exit from the truck to assure that there was adequate clearance to proceed backwards and outboard of the left wing of the airplane. The refuse truck operator then pulled forward approximately 4 feet to allow the airplane to be pulled back to the gate, and parked the truck. According to the American Eagle Embraer EMB Airplane Operations Manual, "Hand signals may be used at the Captain's discretion (e.g. inoperative interphone, inoperative headset or lightning in the area). In these cases, when hand signals are used, the following is required, an additional ground agent will be required, to communicate hand signals to the cockpit, as the push-out vehicle operator cannot safely operate the push-out vehicle and maintain constant visual contact with the Captain during push-out. This additional ground agent will maintain constant visual contact with the Captain during the push-out. A pre-push-out briefing must be held, between the Captain and ground agent, to thoroughly brief the hand signals to be used during push-out. This will ensure that both parties understand what is to occur before, during and after push-out." The captain did not coordinate push-out procedures with ground personnel prior to the pushback, and the additional ground agent was not present.

Verbatim NTSB analysis and probable cause from the NTSB dataset