Alltrikes

Passive Detection System - Power lines.

        One of the most effective systems in keeping aircraft high over the land, or on the other hand, destroying an aircraft that wants to fly low, is the passive detection system we know more familiarly as The Power Line!

        In the military we were told of the devastating affect that one small cable hanging across a valley can have on an aircraft trying to stay under the radar. It had become such a problem that almost all military helicopters are now fitted with WSPS (Wire Strike Protection System). The WSPS is a set of cutting jaws mounted beneath and above the cockpit and these jaws will cut any wire up to 6 cm thick without slowing the aircraft down. Unfortunately for general aviation and Recreational Aviation there is no such system. We must rely on the mark one eye ball!

        The one thing that I hate hearing is that an aircraft has hit power lines and the pilot was killed, or, at best, seriously injured. I sell a lot of pilot's helmets to Ag pilots and they tell me the horror stories of the pilot on his first run for the day, who hits the power line with an aircraft full of fuel and chemicals. More often than not the pilot is seriously injured, and, if he recovers, he gives up flying.

        But three times in two years I have had a phone call to let me know that a good friend has been nearly killed when their aircraft had hit a power line.

        In 2001 Bill Beamish in the Mudgee Clubs X-Air hit a power line. Thankfully neither Bill nor his passenger were injured. Bill had pointed out the power line to the passenger on downwind, and they were discussing how they would get over the power line if they had an engine failure in the circuit. They hit the power line and the aircraft was badly damaged.

        In 2001, only three weeks after Bill's power line encounter, Chris Piper in his Corby Starlet hit a power line near Goolgowi in NSW. He knew it was there. The aircraft was destroyed and Chris was badly injured. Chris told me that it was just a lapse in concentration that caused the crash.

        In August 2002 Jerry Wilson in his Pocket Rocket hit a power line near Bright in Victoria. Another good friend, Greg Withers, who had landed just before Jerry's crash, told me that Jerry had made a radio call to inform Greg that he was going to land at the end with the power line. Thankfully Jerry will fully recover, and at the time of writing Jerry is still in Wangaratta Base Hospital.

        So I would like to put the question to you.... Why did these crashes happen? The pilots knew that the power lines were there, yet they hit them anyway. I don't have an answer for this either.

        I can however tell you what I do when I am about to fly low over unknown terrain.

The first thing I do is have a good hard look for a small dead straight shadow. For me this is the indication of a power pole. Why a straight shadow? In the natural world very few things are straight, but in the manmade world there are lots of straight things, and in a paddock you can almost bet it would be a power pole.

        Some people tell me that they prefer to look for the wire itself.... I am sorry but this is almost a waste of time. Unless the sun is hitting the line in just the right spot, you will have no chance of seeing the power line at all. It is much better to look for the pole and then try to see which direction the wires might go. I tend to look at the whole paddock and then break it down into sections.

        First I look for buildings. If there is a building in or near the paddock, you can almost guarantee that there is some sort of power running to it.

        Next I look at any dams.... A dam could have a water pump and in turn this could have a power line running to it.

        Next I look at any roads running through or along the paddock. These roads could have a power line running along them and of course that power line just might take a short cut across the paddock. But it doesn't have to be a power line, it could be a phone line, although many phone lines are now underground.

        The other type of wire that can fool a pilot is the wire coming from the top of a hill into a paddock. Have a look at Mt Arapiles near Natimuk in Western Victoria. This Mountain is a favorite for rock climbing with its sheer cliffs on the Northern side. But if you look closely at the top you will see a number of towers. One of these towers has a cable coming off it, and this cable runs from the top on a 45 degree angle out into a paddock. It is almost one kilometre out from the base of the sheer cliff. The first time I flew around that area I didn't know about the cable and this almost proved fatal. I was not very close to the Mountain, but a silver flash caught my eye. My instincts took over and I climbed the aircraft and that's when I saw the cable pass just beneath me. Now, orange and white balls have been added to the cable, but it is still hard to see until you are almost on it. It is very easy to see power lines and power poles from the ground looking up, but when you are up there looking down, those same power lines and poles can hide themselves very well.

        Either way if you are planning to do some low flying over terrain that is unfamiliar to you make sure that you, "YES, YOU" check it out really well before doing your let down to your lower altitude. This may prevent you from becoming yet another painful and poorer statistic, another victim of the low visibility passive detection system that is lying in wait for all of us.