A method of preventing ice from blocking a fuel flowpath, the method comprising: urging ice flowing through the fuel flowpath radially outwardly toward an inner surface of a first wall that defines the fuel flowpath; flowing a fluid in a flow passage defin...

Apparatus and method of monitoring for obstructions in a pipe or channel. The method comprising the steps of: (1) transmitting a wave into a first end of the pipe or channel from a transmitting transducer at a first known location relative to the pipe or c...