Canadian regulators have ordered Airbus A220 operators to carry out lubrication tasks on the horizontal stabiliser trim actuator, after occurrences of jamming at the end of cruise.
Transport Canada states that investigation of the events has revealed water intrusion in the actuator’s ballscrew assembly.
“Water intrusion and subsequent freezing has caused jamming of the [actuator] resulting in the loss of pitch-trim capability,” it adds.
Airbus’s Canadian division has developed an improved lubrication method, and reduced the lubrication interval, to mitigate the risk of water accumulation in the ballscrew and possible jamming.
Transport Canada is instructing operators of A220-100s and -300s to carry out initial lubrication tasks within 1,100h of the directive date, and repeat at intervals of 1,000h or 12 months.