Primary finding
Probable cause
The pilot not attaining translational lift during the takeoff. A factor was the high gross weight.
Investigator assessment
Analysis narrative
The helicopter was substantially damaged when it impacted terrain shortly after takeoff. The helicopter was conducting an aerial application flight and had just been loaded with chemical. The helicopter took off, but was not able to climb. It descended into the ground, and rolled onto it's side. Subsequent to the accident, the main rotor blades were found to be contaminated with insect remains. No other anomalies were found.
Source record
Factual narrative
On August 6, 2003, at 1815 central daylight time, a Texas Helicopter OH-13E, N38096, operated by Hendrickson Flying Service, sustained substantial damage when it impacted terrain while on takeoff from a field near Byron, Illinois. The helicopter descended into the ground just after takeoff and rolled over. Visual meteorological conditions prevailed at the time of the accident. The commercial pilot reported minor injuries. The 14 CFR Part 137 aerial application flight was not operating on a flight plan. The flight was originating at the time of the accident. A Federal Aviation Administration inspector reported that the helicopter was conducting agricultural spraying before the accident occurred. After the helicopter landed and was reloaded with pesticides, the helicopter took off, but was not able to climb. It descended into the ground and rolled over onto it's side. The inspector reported that the main rotor blades were contaminated with insect remains. No other anomalies were found that could be determined to have existed prior to the accident. FAA-H-8083-21 - ROTORCRAFT FLYING HANDBOOK states, "Translational lift is present with any horizontal flow of air across the rotor. This increased flow is most noticeable when the airspeed reaches approximately 16 to 24 knots. As the helicopter accelerates through this speed, the rotor moves out of its vortices and is in relatively undisturbed air. The airflow is also now more horizontal, which reduces induced flow and drag with a corresponding increase in angle of attack and lift. The additional lift available at this speed is referred to as 'effective translational lift.'" The pilot has not submitted a report of the accident.