Incident Details

The silencer on the exhaust of the Vittorazi Moster 185 plus came loose and slid down during flight. This caused the exhaust outlet to come into contact with the 18L gas tank installed on the frame/motor and melted a hole in the gas tank in-flight. Other than equipment damage there were no serious consequences.

Root cause was a worn brass wear bushing that had failed, allowing significant vibration to be transmitted through the exhaust pipe into the silencer. The wear bushing had been on the motor for approximately 42 hours and the pilot had assumed it should be replaced at 50 hours. Contributing factor was failure to inspect this wear bushing periodically, instead relying solely on the 50 hour replacement schedule.

Age: 53, Weight: 220 lbs

The silencer on the exhaust of my Vittorazi Moster 185 plus came loose and slide down. This caused the exhaust outlet to come into contact with the 18L gas tank I had installed on the frame/motor and it melted a hole in the gas tank in-flight. Other than equipment damage there were thankfully no serious consequences to this situation. Root cause of the issue seems to have been that the brass wear bushing had worn out, thus allowing much more significant vibration than normal to be transmitted through the exhaust pipe and into the silencer. The wear bushing had been on the motor for ~42 hours and pilot had assumed it should be replaced at 50 hours. Contributing factor/cause was also due to failure to inspect this wear bushing periodically, instead relying on the 50 hour schedule for replacement.