What happened
On April 24, 2013, a Beechcraft 200, registration PR-VIP, operated by Heringer Táxi-Aéreo Ltda, departed from Dianópolis, TO, bound for Palmas, TO. During the takeoff roll, the crew heard an external noise. Upon retracting the landing gear, the crew noted that the nose gear failed to provide a locked indication.
In an attempt to resolve the issue, the crew performed multiple up and down cycles of the landing gear, but the nose gear remained in a "transit" state, failing to lock in either the up or down position. The crew declared an emergency and proceeded to Palmas, where they flew over the city to consume fuel and reduce the aircraft's weight. Following emergency checklists, the crew shut down the engines prior to touchdown. Upon contact with the runway, the nose gear collapsed, causing the aircraft to rest on its nose and the propeller tips. All 6 occupants—two crew members and four passengers—were unharmed, though the aircraft sustained light damage.
The investigation
CENIPA investigators examined the aircraft's nose gear actuator (PN 50-820208-5) at the Department of Aerospace Science and Technology (DCTA). The investigation focused on whether external factors, such as runway debris or animal incursions at the departure airport, contributed to the failure. No irregularities were found at the Dianópolis airfield.
Technical analysis of the actuator revealed that the internal threads of the actuation shaft had worn down, resulting in a loss of effectiveness. This wear allowed the lower retraction arm to move freely without resistance. The investigation confirmed that the component had only completed 183 cycles since its last overhaul (CSO), far below its expected 8,000-cycle interval. Maintenance records indicated that all lubrication and maintenance programs were being followed according to manufacturer specifications, and no active Airworthiness Directives or Service Bulletins were in place to address this specific failure.
Findings
- Internal thread wear within the nose gear actuator caused the component to lose its ability to lock the gear in place.
- The failure occurred significantly earlier than the expected service life, with only 183 cycles completed since the last overhaul.
- No evidence of corrosion or fatigue was found in the actuator system.
- The takeoff runway was clear of any hazards that could have caused the initial noise or damage.