What happened
On July 23, 2019, a Super Petrel LS amphibious biplane, registration PU-SUC, was performing a flight from Tefé to the Coari region in Amazonas, Brazil. The flight was transporting a passenger, a technician, to perform maintenance on internet towers. Due to delays at a previous destination, the pilot decided to divert to the Coari Aerodrome.
At approximately 22:15 UTC, the pilot attempted a water landing on the Coari River. During the landing sequence, the aircraft experienced a slight fluctuation following the initial contact with the water, likely caused by a relatively heavy touchdown. During this moment, the landing gear lever inadvertently dislodged from its retracted position. The landing gear extended seconds before the second contact with the water, causing the aircraft to capsize. The aircraft sustained substantial damage, while the pilot sustained light injuries and the passenger remained uninjured.
The investigation
CENIPA investigators examined the aircraft's mechanical configuration and the pilot's credentials. The investigation confirmed that the pilot was properly rated and medically certified for the operation, and the aircraft held a valid experimental flight authorization. The aircraft was within weight and balance limits, though investigators noted that the maintenance logs for the engine, propeller, and airframe lacked updated flight hour records.
Technical analysis focused on the landing gear locking mechanism. The mechanism relied on a manual lever secured by a rubberized loop. Investigators found that this loop was worn and had developed excessive play. This wear, combined with the material properties of the locking component, allowed the lever to slip from its secured position, especially if the pilot had not fully seated the lever or if the aircraft experienced sudden movement.
Findings
- The landing gear lever was not in the correct position for a water landing.
- The inadvertent extension of the landing gear during the water landing caused the aircraft to capsize.
- The rubberized locking loop on the landing gear lever was worn and lacked the necessary tension to prevent accidental movement.
- Maintenance records for the engine, propeller, and airframe were not up to date.