What happened
On July 25, 2022, an experimental Vans RV-9A, registration N192MH, was destroyed during a flight near Tryon, Nebraska. The flight, operated under Part 91 regulations, departed Greeley-Weld County Airport in Colorado, bound for Cherokee County Regional Airport in Iowa. The aircraft was occupied by a pilot and a student pilot-rated passenger.
During the flight, the pilot requested VFR flight following from Air Traffic Control (ATC). While initially flying at 9,50' feet MSL, the pilot reported encountering moderate precipitation and later requested a deviation to avoid overcast conditions. At 0831, the pilot indicated they were attempting to remain clear of clouds and intended to climb to get on top of the cloud layer.
At 0837, the pilot reported being at 12,300 feet and stated they were "still in the soup." Shortly after this communication, radar data showed the aircraft entered a descending left-hand turn. Within 20 seconds, the aircraft descended approximately 4,800 feet and accelerated to speeds between 249 and 264 knots TAS, which exceeded the aircraft's maximum airspeed of 182 knots TAS. Witnesses on the ground reported hearing a loud boom and observing the airplane in a spiral before it impacted the ground. The accident resulted in 2 fatal injuries.
The investigation
Investigators examined the debris field, which spanned approximately 900 feet and began about one mile northwest of the main wreckage. The wreckage distribution, including separated portions of the vertical stabilizer, rudder, and wings, was consistent with an in-flight breakup.
Mechanical examination of the wreckage revealed that the left wing had separated from the fuselage, with the upper spar cap fractured and the wingtip broken into multiple pieces. The right wing also showed partial separation and downward bending. The vertical stabilizer and rudder had also experienced significant damage, including fractures and deformations. The investigation found that the observed damage was consistent with structural failure initiated by rudder flutter.
Findings
- The pilot was not instrument-rated and continued to fly toward deteriorating weather conditions despite being aware of the clouds.
- The pilot likely experienced spatial disorientation after entering instrument meteorological conditions (IMC) and losing visual references.
- This disorientation led to a loss of control and a rapid descent.
- The aircraft exceeded its design airspeed limits, which triggered the flutter of the rudder, leading to the structural failure of the airplane.