The National Transportation Safety Board (NTSB) has called on the Federal Aviation Administration (FAA) and Textron Aviation to take action following multiple Cessna 210 and 210B accidents linked to fatigue cracking in hydraulic landing gear actuators.
Actuator failures were key elements of five accidents related to landing gear collapses or forced emergency gear-up landings since 2015, the NTSB said. In each case, investigators found fatigue cracks that originated from pitting corrosion in the actuator housing.
Investigators said the failure’s root cause was in the aluminum alloy used in the actuator body, which is prone to pitting corrosion in stress-prone areas of the retainer ring groove. Once cracks developed, they spread until the housing fractured, causing a loss of hydraulic fluid and rendering the landing gear system inoperative.
“Since these cracks are entirely inside the actuator, they would be difficult to find with many standard techniques,” the NTSB wrote.
The board stated that advanced inspections, such as ultrasonic or eddy current testing, could detect the cracks before catastrophic failure, though no life-limit or overhaul schedule currently exists for the affected actuators.
In its recommendations, the NTSB urged Textron Aviation to develop inspection criteria, overhaul intervals, and life-limits for the actuators, followed by a service bulletin to operators. The agency also recommended that the FAA issue an airworthiness directive once Textron’s bulletin is released.
While no serious injuries have been reported in connection with these failures, the NTSB cautioned that the risk of a gear-up landing remains significant if the issue is not addressed.
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