Abstract: Employee #1, of United Airlines, was assigned for the first time to test the airflow of the aft cargo compartment heater fan of a 757 aircraft undergoing checks. She had not received any prior specific training regarding this new assignment, nor had she assisted anyone doing a similar job. She was unfamiliar with the equipment to be tested and also complained that the test procedures were confusing. The test required the employee to feel the airflow by placing a hand near the nozzle. Employee #1 placed her hand near the wrong nozzle (with exposed blades) and her hand was sucked into the blades and cut. The previous shift crew had removed more tubing than necessary, thereby exposing the fan blades of the heater fan motor. From the time she started working at 7:00 a.m. until 10:30 a.m., when she was hurt, no supervisor either checked on her or supervised her.