Wire Strikes
I find it unusual that wire strikes this year have taken the spotlight for ag aviation accidents. However, one cannot deny the facts; wire strikes are rising. Several of the ten fatalities (so far) this year can be attributed to the aircraft coming in contact with a wire. Surprisingly, many strikes are believed to have been made by pilots who supposedly knew the existence of the powerline.
Few experienced, high-time ag pilots have not had a wire strike. Most live to talk about it; some don’t. An old saying goes, “If the wire is too small to see, then you will probably fly through it. You probably won’t fly through it if it is large enough to see.” Never mind if the wire is flown through, the potential damage to the turbine engine, prop and airframe.
I would not bet my life on that saying. This is especially true if the pilot is flying a helicopter. I dragged a few wires back to the airstrip and even caused a roadside fire with one. In every case, the wire strike was my fault because I knew the wire was there.
I consider high-tension wires the most dangerous. They are sometimes known as devil horns. Typically, there is enough space to get under wires near supporting towers if you don’t misjudge and hit the tower. As temperatures build during summer, wires tend to sag in the middle between the towers. Maybe there was clearance earlier in the year, but not so much in the heat of the summer. It is almost a sure bet coming in contact with a high-tension/cross-country powerline will bring the aircraft down. The odds are much better with the typical single wires carrying power to a barn or house. But they sag as well.
It does not matter. A wire is a wire, and the end result will always be unknown until after the event. All wires demand undivided attention – if that is even possible in an ag plane. Of course, if the whereabouts of the wire are known before spraying the field, the pilot has an excellent chance of mitigating the wire risk. Even so, pilots keep coming in contact with wires they knew existed.
A few things can be done to reduce the wire risk. First, know where the wire is located either through a map preview, fellow pilots, or a firsthand field inspection before the application. I flew for an operator in my last years as an ag-pilot, and I held much respect for his advice. He told me, “Fly the field as good as the farmer planted it.” He was telling me to fly over the wire or spray parallel to it. But pilots still hit wires even after the aforementioned.
Why? It could be several things: lack of skill, being blinded by the sun, a mechanical distraction, pilot fatigue and the list could go on. The wire does not move, except in the case of heat sagging. It is ultimately the pilot’s responsibility to be wire-aware and do whatever is necessary to avoid coming in contact with one. I doubt there are any NTSB reports for wire strikes that the pilot was not at fault.
Educating yourself about flying in the wire environment is valuable in avoiding them. At this year’s Ag Aviation Expo, there will be a vital seminar on wire strikes. Attending may save your life one day. It doesn’t matter how many ag hours you have; nobody knows everything about flying in the wire environment. It is time to take a more brutal look at wire strikes, acknowledging that most fatalities this year were caused by these sneaky obstacles!
Until next month, Keep Turning…
