What happened
On August 3, 2016, a Beechcraft B36TC, registration PP-MMJ, was performing a visual flight rules (VFR) passenger transport flight from Porto Velho to Lábrea, Amazonas. During the approach to runway 36 at Lábrea Aerodrome, the pilot noted a drop in airspeed, prompting a power increase. However, as the aircraft neared the threshold, the pilot reduced power to idle to manage the speed.
Upon touchdown, the aircraft entered a porpoising motion. During this sequence of bounces, the nose gear sustained structural damage and collapsed. The loss of the nose wheel prevented the pilot from executing a go-around, as the aircraft began dragging the gear along the runway. The aircraft veered to the right and traveled 255 meters before coming to a stop. The propeller blades struck the runway surface, causing a sudden engine stoppage. The pilot and three passengers escaped the aircraft without injury.
The investigation
CENIPA investigators examined the aircraft's nose gear and found that the wheel axle was bent and the fork had sustained fractures at approximately a 45-degree angle, indicating the damage was caused by structural overload. The investigation also reviewed the runway surface; while the pilot reported that runway deformations had contributed to the bouncing, investigators found no significant irregularities on the central part of the runway capable of causing such an effect.
Regarding the flight parameters, the investigation found that the aircraft crossed the runway threshold at approximately 100 knots, which was above the manufacturer's recommended approach speed of 85 knots. The investigation also noted that while the aircraft's airworthiness certificate was valid, the maintenance logs for the airframe, engine, and propeller were not up to date.
Findings
- Failure to execute a go-around: The pilot identified the onset of porpoising but did not attempt a go-around, likely due to concerns regarding dense smoke visible at the opposite end of the runway.
- Inadequate flight controls: Improper management of airspeed during the final approach led to an approach speed exceeding manufacturer recommendations, contributing to the unstable landing.
- Structural overload: The repeated impacts of the porpoising motion caused the nose gear to fracture.
- Maintenance documentation: The aircraft's logbooks for the airframe, engine, and propeller were outdated.