Originally Posted by
Fursty Ferret
I'm not convinced this necessarily applies here. Ratio calculations are notoriously easy to get wrong. Even the very best people make simple mistakes when dealing with parts per million (because it adds an extra step to a calculation) and this is likely exacerbated when working at night, tired, and under time pressure. There are some simple and obvious steps that can be taken to prevent this happening again:
1. Provide a worked example of the calculation in the maintenance manual.
2. Provide an electronic calculation in the maintenance manual (input contamination, biocide, fuel quantity and it spits out the required dose).
3. Supply the biocide in smaller containers. Even the person who's absolutely confident of their calculation will think again if they realise they have to log, open and pour (for example) 60 bottles of the stuff into the aircraft.
Surely any ongoing competency assessment/training would account for this? As I previously said, many uncomfortable questions opening a can of worms, all too easy to blame the individual and not the organisational and procedural failings.