ERA20LA149 · Pipistrel Italia SRL Sinus 912 LSA

The pilot of the motor glider performed a preflight inspection, departed the airport, and remained in the local area conducting maneuvers. Witnesses observed the glider about a mile from the airport and reported hearing unusually loud noises coming from it and, subsequently, a laboring engine. The glider had the appearance of wobbling; the engine surged and sputtered, and the glider then made a sharp left turn and the nose dropped. The glider's airframe ballistic parachute deployed shortly before the impact with a residential home and a postimpact fire ensued. It is likely that the glider entered an aerodynamic stall and an entry phase of a spin prior to impact. It is also likely that, despite the pilot’s attempt to pull the airframe parachute, it was not deployed at a sufficient altitude to arrest the descent. The airframe was destroyed by post-impact fire, which precluded an examination of the flight control system. Examination of the engine did not reveal any preimpact anomalies that would have precluded normal operation. Toxicology testing detected three potentially impairing substances in the pilot’s specimens. The sedating antihistamine diphenhydramine was detected in his blood and not quantified by one laboratory and not detected in iliac blood by another laboratory. While diphenhydramine is known to cause sedation, the level detected in the pilot’s blood appears to be well below therapeutic levels. Although no absolute threshold for impairment exists, any psychomotor effects from such a low diphenhydramine level would likely have been insignificant. The motion sickness medication meclizine was also detected but not quantified in the pilot’s blood. While meclizine can cause drowsiness, it’s also likely that any effects would have been minor at low concentrations detected. Duloxetine was detected at therapeutic levels in the pilot’s blood. The medication and conditions for which it is prescribed can impair the mental or physical ability to perform complex tasks. However, based on the operational evidence, the pilot appeared to have been intentionally testing the glider and took actions, although too late, to deploy the parachute. Thus, it is unlikely that effects from the pilot’s use of diphenhydramine, duloxetine, and meclizine were factors in the accident.

Verbatim NTSB analysis and probable cause from the NTSB dataset