skyrangerpro: If it really is impossible to design a pump that is able to be put in an automatic mode and we are stuck with xfer switches that are dependant on pilot management, they should at the very least be in direct line of sight and even better, positioned right below the relevant captions in the WU.
A friend of mine, who was assisting a HEMS Corp. fleet admin, claimed EC135 come (came?) with different types of transfer pumps. There are pumps (model years?, configurations?) that can run dry up to 5 min only, then there are those we're talking about which can run dry for 20min (AAIB report) and apparently there are transfer pumps (in the BO105 for sure) that noone ever has to switch off, no matter how low the level in the main tank is.
N.B. Said company owns multiple BOs and one EC135, so they should know.
Anyone here knowledgable about types of EC135 transfer pumps?