… The key to preventing disasters … is regular inspection of sewer lines, hunting down any cracks and fissures that, if left unattended, can lead to soil ingress and eventual collapse of the pipe. Sewer pipes can be dark, cramped, and filled with pockets of gas, making inspecting large networks using traditional methods (typically a tethered, remotely operated crawler fitted with a camera or even in-person) a slow, costly, and often hazardous process. This is where drones come in. Designed and engineered to operate in confined spaces, a new generation of flying robots is being sent into sewers to perform inspections in a safer, more efficient way.