What happened
On April 15, 2018, a Quest Kodiak 100 (registration JA02TG) operated by Setouchi SEAPLANES Inc. was conducting a familiarization flight in the waters near Sakaigahama, Urasaki Town. The flight, which included a pilot and an advisor, involved a series of repeated take-offs and touchdowns to practice landing techniques.
During the ninth landing attempt, the pilot attempted a crosswind approach from the left. After touching down, the aircraft began to veer due to the weathercock effect. In an attempt to manage the aircraft, the pilot began to fluctuate the engine power. While the pilot initially intended to perform a go-around, the advisor's inquiry regarding the power increase led the pilot to attempt to continue the landing instead. This decision resulted in the aircraft becoming airborne again and subsequently bouncing repeatedly on the water surface. During these bounces, the aircraft's nose dropped significantly, leading to a heavy impact on the right float.
Following the impact, the crew heard a loud breakage and the advisor took control of the aircraft to execute an emergency go-around. After confirming structural damage to the float struts, the crew diverted to Kounan Airport for an emergency landing.
The investigation
The Japan Transport Safety Board (JTSB) examined the flight data from the Integrated Instrument System and analyzed the pilot's maneuvers. The investigation focused on the sequence of power applications, the aircraft's vertical acceleration during the bounces, and the communication between the pilot and the advisor. The investigators also reviewed the company's training manuals regarding crosswind landing procedures and go-around criteria.
Findings
- The aircraft suffered substantial damage, specifically a broken right front strut, damaged attachment structures, and damaged fairings on both main struts.
- The pilot's decision to reject a necessary go-around was a critical factor; the pilot attempted to stabilize the aircraft through inconsistent power adjustments rather than executing a clean departure.
- The pilot failed to stabilize the aircraft during the bouncing motion, which led to the hard touchdown that caused the structural failure.
- The crosswind component during the landing attempt had exceeded the company's operational limitations.
- There was a lack of clear communication and coordination between the pilot and the advisor during the critical moments of the landing attempt.