Amateur-built RV14 accident near Virden, Illinois, August 12, 2023

The NTSB's narrative final · quoted from the NTSB record

Witnesses observed the accident airplane flying inverted at a low altitude heading southwest before it banked left and rolled upright. The airplane then collided with trees and terrain. ADS-B data combined with data retrieved from on-board avionics revealed that, while in the climb to a cruise altitude, the pilot, who was also the airplane builder, changed the vertical mode several times, which appeared to be an attempt to get the airplane to climb to a higher altitude. For undetermined reasons, the pilot’s operation of the autopilot during the accident flight did not match his usage in previous flights. During the mode change events, the canopy open inflight annunciator began to intermittently and frequently display to the pilot. Performance data indicated that, about 9 minutes into the flight, the airplane began a rapid pitch down and right rolling maneuver. The flightpath was not consistent with an aerobatic flight or any aerobatic maneuver. The inflight upset resulted in the airplane rolling inverted and changing the direction of flight. While data ended with the airplane inverted, impact signatures and eyewitnesses accounts are consistent with the pilot having rolled the airplane upright before impact with terrain. The investigation identified a static pressure anomaly in the flight data just before, and which persisted through, the inflight upset. As part of the investigation, a test pilot conducted maneuvers to try to replicate the accident inflight upset, but none of the maneuvers replicated the static pressure anomaly detected in the accident flight data. Based on the accident and test flight data, the inflight upset was not likely a result of control inputs and was likely due to the canopy opening inflight. A Van’s service letter indicate that a rapid nose-down moment can be encountered if a tip-up canopy opens in flight, which is consistent with the recorded accident data. Postaccident examination of the flight controls and engine did not find any anomalies that would have contributed to the inflight upset. Examination of the airplane’s canopy found gouges in the canopy pin blocks starting from the holes where the latch pins seat downward, in a manner consistent with the tip-up canopy opening with force in flight (see figure 2, in the Wreckage and Impact section). The canopy handle was found in the closed position; however, the investigation was unable to determine if the handle was placed there during the pilot’s recovery attempt or had moved forward with inertia during impact. The airplane’s canopy latch micro switch was installed in a manner that would have signaled a closed canopy before the canopy pins were fully seated. Additionally, a AA-size battery was found in the area of the elevator control rod. One side of the battery displayed a semicircular dent similar to the elevator control rod; on the other side was a small dent with nearly the same diameter as a rivet. Before the accident, this area would have been covered with panels and the control sticks had boots; accordingly, the investigation was unable to determine when the battery was introduced to the control rod area, whether it was damaged during the accident, or if its presence contributed to the accident. No record of the pilot completing a recent BasicMed Comprehensive Medical Examination Checklist was found. Toxicological evidence indicated that the pilot had used lorazepam, venlafaxine, and quetiapine, all which could cause some degree of central nervous system depression. When used in combination, the risk for adverse effects may increase. The investigation could not determine if the pilot’s use of these medications, or if the underlying conditions for which he was taking the medications, may have contributed to the accident. The circumstances of the accident are consistent with the pilot not fully closing the canopy before flight. Because the canopy latch micro switch would have signaled a closed canopy before the pins were fully seated, the pilot likely thought that the canopy was fully closed when it was not. When the canopy opened in flight, the airplane entered a right roll, rapid pitch down, and became inverted. Although the pilot was able to reorient the inverted airplane, he was unable to fully recover control before impacting terrain.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.