Whilst preparing to fit a new Emergency Breathing System (EBS) bottle to a lifejacket, the burst plug activated, discharging the contents of the EBS. Investigation determined that an incorrect burst plug had been fitted to the original EBS and instead of 4500 PSI / 310 BAR working pressure burst plug, the unit had been fitted with a 3000 PSI / 207 BAR working pressure burst plug. This condition, if not detected and corrected, could lead, in case of ditching, to failure of the EBS system in providing an alternative, or additional means to mitigate the risk of drowning.
To address this potential unsafe condition, Survitec issued Alert Service Bulletin 25-206-A. For the reasons described above, this AD requires a one-time inspection of the burst plug and reporting the results of the inspection back to the manufacturer.
Source: CAA.