Investigation Summary
The accident occurred during a night departure at Chicago O'Hare International Airport. During engine start, the flight crew identified an electrical fault involving the DC bus protection control unit (DCBPCU). This failure prevented the distribution of DC power, causing the external lights to fail and preventing the aircraft from accepting external ground power. While the crew and maintenance personnel were troubleshooting the issue, the right engine remained running to provide cabin lighting and cooling. A baggage handler from American Airlines, who had previously worked as a cabin cleaner on jet aircraft, was dispatched to deliver skis to the flight. She arrived at the rear of the aircraft and, after briefly opening the right rear service door, walked forward along the right side of the fuselage. At the same time, a marshaller was at the forward right fuselage attempting to connect a ground power unit. A passenger observed the handler walk forward into the rotating propeller. The investigation revealed that the handler had received no formal classroom or practical training for her transition from cabin cleaner to baggage handler, and her previous experience was exclusively with jet aircraft where propellers are not a hazard.
Final Conclusions
The National Transportation Safety Board determined the probable cause to be the unqualified baggage handler's attempt to load an unfamiliar airplane and the inadequate training provided by the airline that employed her. Contributing factors included the dark night conditions, the failure of the aircraft's external lighting system due to an electrical fault, and the handler's diverted attention while performing maintenance-related service in an unsafe environment.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
First Officer
Systems & Failure Modes
DC Bus Protection Control Unit (DCBPCU)
A component that screens DC electrical power before distribution; its failure in this instance caused a total loss of external lighting and prevented the use of external power.
Propeller Brake
A system on the ATR-42 that can stop the right propeller from rotating while the engine is running (Hotel Mode), though it was not engaged during this ground troubleshooting sequence.
External Lighting
Includes navigation and anti-collision lights; these were unpowered due to the DC electrical fault, reducing the visibility of the rotating propeller at night.
Interesting Facts
- 01The baggage handler was on her second day of work as a baggage handler and her first night shift in that capacity.
- 02The handler's previous experience was as a cabin cleaner for jet aircraft, which involved no exposure to propeller hazards.
- 03The aircraft's external lighting was inoperative at the time of the accident due to a failed DC bus protection control unit.
- 04The lower anti-collision beacon was already listed as inoperative prior to the flight under the Minimum Equipment List (MEL).
- 05The baggage handler was wearing sound-suppressing earmuffs at the time of the impact.
- 06The airline's training for fleet service clerks did not formally track or require the viewing of turboprop safety videos.
Safety Actions & Advisories
Formalization of Turboprop Safety Training
Source ↗Following the accident, it was identified that the Simmons Airlines turboprop safety video was not formally tracked in American Airlines' automated training system for fleet service clerks. The airline indicated a commitment to providing further instruction and formalizing the tracking of such training for personnel transitioning from jet-only environments to roles involving turboprop aircraft.