Following the completion of the refueling procedure on the aircraft, fuel company personnel walked up the aircraft forward stair in order to have the relevant fuel form signed and take a copy of such signed form. Upon the opening of the aircraft door, the door hit him causing him to fall on the ground from a height of about three meters and sustain serious injuries. Probable Causes The failure to follow the procedures and in particular the absence of an airline representative on the ground, to prevent the employee from using the folding stair when the handrails at its uppermost part were not extended. Contributing Factors The weather conditions that at the time prevailed at the site of the accident (heavy rain and strong wind) possibly prevented the airline representative from being on the ground in order to prevent the fuel company employee from using the folding stair. Moreover, weather conditions forced the cabin crew to close the door, when normally the door remains open during the phase of pre-flight procedures.