When I was the CO of a Super Puma Helicopter Squadron in Brazilian Navy, in 1998, I flew into a 138000 V power line. Fortunately I got the upper lightning protection wire – not a live line – entangled on my nose wheel.
We were flying at 400 ft and the line was crossing a valley, between two hills. When I noticed I was trapped by the wire, I jettisoned the external load (1.5 tons of dummy ammo crates). It fell like a bomb, opening a crater on the terrain below.
I tried to break the wire flying ahead, but the wire was too thick and it pulled my nose down reducing drastically the lift component, causing a fast loss of height, that I compensated pulling the nose up. I performed two more times this maneuver that turned us into a gigantic “yoyo”, until I realized what was happening. From this moment I made an attempt to put the wire on the reach of the winch man, so he could possibly cut it with the portable cable cutter, but we didn’t succeeded with that. It would never have worked as, on the ground, we needed three people to cut the cable using the portable cable cutter…
After these frantic efforts to free the aircraft from the cable I decided to lift the cable to break the “catenaries”, hoping the cable weight would shear it.
Amazingly it worked. We managed to break the cable and, despite the fact that a piece of wire hanging from the helicopter has touched one of the live wires after breaking, the energy was grounded to one of the towers and we were able to land the aircraft safely.
We were lucky enough to survive and tell the tale. Our experience and training saved lives! There were many systemic aspects that compromised my decision process that were identified on the following investigation: poor CRM, bad use of crewing procedures, excessive self-confidence, among others.
Today we pass these experiences – that encompass this episode and a few others, from my personal background and from another selected professionals – to Industrial and Aviation safety worlds, trying to help people identifying the chain of the accident to improve prevention, by teaching courses of our methodology, called APICE.