What happened
On December 30, 2016, at approximately 13:35 UTC, a motorized hang glider, an Aeros Profi 14 with registration OK-TZX 01, crashed near the village of Mutěnice in the Czech Republic. The pilot had departed from a landing site near Dolní Bojanovice and was flying in the vicinity of Hodonín.
Witnesses on the ground observed the aircraft flying at a low altitude. The pilot performed a low-level pass, waving to bystanders, before grasping the control bar with both hands and initiating a steep climb at an angle of approximately 45 degrees. As the aircraft reached an altitude of roughly 30 to 40 meters, it suddenly pitched nose-down. The aircraft entered a rapid rotation around its lateral axis, performing a 36 and a half roll that resulted in an inverted loop. The aircraft struck the ground with its right wing first, causing the structure to disintegrate and the pilot to be ejected from the seat. Despite immediate resuscitation efforts by bystanders and emergency medical services, the pilot, a 57-year-old male, succumbed to multiple traumatic injuries at the scene.
The investigation
The ÚZPLN investigation examined the aircraft's condition, the pilot's credentials, and witness testimonies. The investigation confirmed that the Aeros Profi 14 was in good technical condition with no pre-impact structural defects or assembly errors. The engine, a Subaru EA 81, was found to have been functional during the flight, and all mechanical damage observed was consistent with the impact forces.
The pilot held valid medical and pilot certifications and was not under the influence of alcohol or drugs. The investigation also reviewed the meteorological conditions, which were stable with clear skies and light winds, ruling out weather as a contributing factor.
Findings
- The pilot performed a low-altitude descent in violation of VFR regulations to greet individuals on the ground.
- The pilot intentionally executed a steep climb exceeding the recommended 30-degree pitch limit.
- The primary cause of the accident was improper piloting, specifically exceeding the safe climb angle, which led to a loss of airspeed and a subsequent transition into an uncontrollable inverted loop.
- The aircraft's momentum and the high angle of attack at the top of the maneuver triggered a parametric roll, making the subsequent flight path unrecoverable.