Main power lines are easy to see, but when flying in their vicinity you must take the time to look for what is really there and then use safe procedures. Remember, the human eye is limited, so if the background landscape does not provide sufficient contrast then you will not see a wire or cable. Although hydro structures are big and generally quite visible, a hidden danger exists in the wires around them.
The figure shown above emphasizes this point. The main conductor cluster is made up of several heavy wires. These heavy, sagging conductors are about two inches in diameter, and very visible, so they tend to distract one from seeing the guard or lightning protection wires, which are of much smaller diameter.
Guard wires do not sag the way the main conductors do and are difficult to pick out even in good visibility. The only way to be safe is to avoid the span portion of the line and always cross at a tower, maintaining a safe altitude, with as much clearance as possible.
- When following power lines, remain on the right-hand side relative to your direction of flight and watch for cross lines and guy cables.
- Expect radio and electrical interference in the vicinity of power lines.
- For operational low flying, do an overflight and map check first.
- Leave yourself an "out" - cross at 45 degrees to the line.
- Reduce speed in low visibility (for VFR - two mile visibility; clear of cloud; 165 kt max.).
Warning - Intentional low flying is hazardous. Transport Canada advises all pilots that low flying for weather avoidance or operational requirements is a high-risk activity.
Flying near power lines - TP 2228-4
(PDF, 38 KB)