1. During routine inspection of a reciprocating engine, a deposit of small, bright, metallic particles which do not cling to the magnetic drain plug is discovered in the oil sump and on the surface of the oil filter. This condition A. may be a result of abnormal plain type bearing wear and is cause for further investigation. B. is probably a result of ring and cylinder wall wear and is cause for engine removal and/or overhaul. C. is normal in engines utilizing plain type bearings and aluminum pistons and is not cause for alarm.