Bell 206A N949FM accident near Wenatchee, Washington

Probable cause

The pilot's failure to maintain a proper decent rate and path, which resulted in a hard landing and dynamic rollover. Contributing to the accident was the pilot's impairment by a sedating medication.

NTSB analysis

The commercial pilot was drying cherry trees, which called for low-level flying in the helicopter. The landing area was slightly uphill with the ground tilted slightly to the right. Although the pilot had taken off and landed in that location at least once earlier in the day, wreckage documentation and ground scars revealed that, during the accident landing, the helicopter landed hard enough and with sufficient lateral motion to cause a dynamic rollover. No witnesses visually observed the accident; however, one witness heard the helicopter, followed by a thud and then silence. This witness responded to the accident and observed the helicopter on its side and smoking. Postaccident examination of the airframe and engine revealed no evidence of mechanical failures or malfunctions that would have precluded normal operation.

Results of toxicology testing for the pilot detected therapeutic levels of tramadol, which is not known to undergo significant postmortem redistribution. Therefore, the identified levels likely represented his antemortem level of tramadol. Although with regular use people can develop a tolerance to the impairing effects of opioids, in this case, the pilot was engaging in a high workload and high risk portion of flight, and even a small level of impairment could have contributed to his inability to safely land the helicopter.

The Federal Aviation Administration recommends that pilots using sedating medications on an occasional basis wait five maximum dosing intervals before flight. For tramadol that computes to waiting 40 hours (8 hours x 5) before flying; this pilot's therapeutic level suggests that he did not follow this recommendation. The pilot's impairment by tramadol likely contributed to the accident.

Text from the NTSB. Open the NTSB docket for WPR14FA310 for the full record.