Inlet system for auxiliary power unit

An auxiliary power unit, comprising:

• an inlet duct;
• a frame coupled about the inlet duct, the frame defining an opening configured to be in fluid communication with the inlet duct;
• a door having a first end opposite a second end, the door coupled to the frame at the second end, the door configured to pivot about a pivot axis relative to the frame between at least a first, closed position in which the door cooperates with the frame to inhibit airflow into the inlet duct and a second, opened position in which the first end of the door is spaced apart from the frame to enable the airflow into or out of the inlet duct, the door defining a ramp at the second end that extends outwardly about a portion of the pivot axis;
• and
• a hook coupled to the frame proximate the inlet duct and proximate the second end of the door, the hook spaced a distance apart from the ramp to define a gap configured to enable the airflow into or out of the inlet duct in the second, opened position and the gap is continuous between the hook and the ramp.