Investigation Summary
On the day of the accident, the ramp agent was returning to work after a 30-day leave following the relocation of US Airways Express operations from Dulles to Reagan National Airport. Throughout the shift, which began at 08:35 EDT, the agent exhibited signs of fatigue and physical distress. At approximately 15:40, he complained of a headache and was later observed resting in the baggage compartment of a different aircraft. The temperature at the time of the accident was 84 degrees F with a heat index of 91 degrees F, conditions known to exacerbate the symptoms of hyperthyroidism. As Flight 3340 prepared for departure, the agent removed the nose landing gear chocks but inadvertently tossed them into the path of the right main landing gear. When the aircraft began to move forward, the marshaller signaled the captain to stop. The ramp agent, apparently realizing his error, moved toward the moving aircraft to retrieve the chocks. Witnesses shouted for him to stop, but he continued into the path of the right engine's propeller. The NTSB investigation focused heavily on the agent's medical history, noting that his thyroid hormone levels were markedly elevated just one month prior to the accident, and he had recently been prescribed alprazolam (Xanax), which can impair cognitive and psychomotor performance.
Final Conclusions
The National Transportation Safety Board determined the probable cause to be the ramp agent's impaired performance due to hyperthyroidism, exacerbated by heat and inadequate medical control, and possibly the use of antianxiety medication. The NTSB issued its final report on October 2, 2002.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Class 1 Valid Medical w/ waivers/lim. Flight time in last 90 days: 158 hours; last 30 days: 46 hours; last 24 hours: 5 hours.
Systems & Failure Modes
Propeller System
The Dash 8-100 is equipped with two Pratt & Whitney Canada PW120 turboprop engines driving large-diameter propellers.
Interesting Facts
- 01The ramp agent had been diagnosed with Graves' hyperthyroidism approximately eight months before the accident.
- 02Toxicological testing detected propranolol, a medication used to control symptoms of hyperthyroidism.
- 03The agent had been prescribed alprazolam (Xanax) ten days prior to the accident for anxiety.
- 04The heat index at the airport was 91 degrees F at the time of the accident.
- 05The aircraft involved, N935HA (MSN 142), was manufactured in 1989 and sustained only minor damage.
- 06The starboard engine propellers were rotating at approximately 780 rpm at the time of the strike.
- 07The accident occurred on the ramp agent's first day back from a 30-day leave and his first day at Reagan National Airport following a base relocation.
Safety Actions & Advisories
Medical Oversight and Ground Safety
The NTSB investigation highlighted the risks of impaired performance due to medical conditions like hyperthyroidism and the side effects of medications such as alprazolam, especially when exacerbated by high ambient heat. The findings emphasized the importance of ground personnel being fit for duty and the potential for cognitive impairment to lead to fatal errors in high-noise environments where verbal warnings may not be heard.
Location
NO VERIFIED COORDINATES · Coordinates are the estimate published in the ntsb final report. No map is shown, because a marker here would imply a precision the record does not have.
Reported location: Washington, District of Columbia, United States