Originally Posted by Concentric
When you get a chip indication how many metal chips do you know there are?
Posted by rifraf
The obvious answer is, "enough ferrous debris to bridge the sensor gap".
I would add - if you're lucky. I had a Chinook gearbox which started to make a loud whining noise whilst flying across Falklands Sound - but no indications, so we turned round and went back to San Carlos. On shut down we didn't need a rotor brake -they slowed down so quickly. When the engineers pulled the mag plug on the combining box it was christmas tree'd with metal debris, and even more fell out of the hole! The plug was proved to work on the ground, however, it seemed there was so much debris it never made the connection to give a chip warning. The gear box was a write off. My lucky day.