What happened
On April 17, 2017, a Hamilton SH-1 Glastar, registration SE-XUG, was conducting water landing practice on Lake Øyeren in Enebakk, Norway. The aircraft, an experimental-class plane equipped with amphibious floats, was operated by a single pilot.
During the approach, the pilot noted that the aircraft was sinking more than usual. In an attempt to abort the landing, the pilot increased power, but the aircraft failed to climb. Upon contact with the water, the left float struck first, causing the aircraft to veer sharply to the left and tilt to the right. The right wingtip dipped into the water, causing the aircraft to pitch forward and capsize. The aircraft ended up upside down in the lake, floating on its floats.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the aircraft's condition, meteorological data, and the pilot's evacuation process. The investigation confirmed that the aircraft was in good mechanical condition with no technical failures contributing to the accident.
Investigators analyzed the wind conditions, finding that while the pilot had estimated a headwind, a light crosswind of approximately 5-6 knots was actually present. The investigation also looked into the failure of emergency signaling. Although the aircraft's Emergency Locator Transmitter (ELT) activated automatically due to the impact forces, the signal was not received because the antenna was submerged under the water after the aircraft overturned.
Findings
- The primary cause of the accident was operational in nature, specifically the pilot's failure to be sufficiently decisive with power application when noticing the increased sink rate.
- A light crosswind contributed to the loss of control during the landing sequence.
- The pilot successfully evacuated the inverted aircraft by using a pre-planned method of feeling for the door latch by hand, which helped overcome the disorientation caused by rising water levels.
- The pilot was not wearing a life vest, and a handheld Personal Locator Beacon (PLB) remained inside the aircraft and was not carried during the evacuation.
Safety action
- The NSIA noted that the pilot's practice of visualizing an emergency evacuation was highly beneficial during the actual event.
- The investigation highlighted the importance of wearing appropriate life vests during water operations and ensuring that Personal Locator Beacons (PLBs) are worn on the person to be available during an evacuation.