PORTLAND, Maine (AP) — A federal agency has issued a warning to the Maine-based operator of a natural gas pipeline over its failure to complete regular inspections of the 143-mile transmission line.

The Portland Natural Gas Transmission System is supposed to conduct an aerial inspection of the entire pipeline once a week. The Pipeline and Hazardous Materials Safety Administration says the company stopped doing them because the company hired to conduct them couldn’t find qualified pilots.

The Portland Press Herald reports (http://bit.ly/p26iiJ ) that leaks show up in aerial inspections because nearby vegetation dies.

TransCanada, majority owner and operator of the pipeline, says the situation was rectified immediately after problems were uncovered during an audit.