A day, my boss consulted me about the possibility of using a much smaller aircraft that can carry electromagnetic (EM) sensors for detecting electrical conductive formations (ECM). The current airborne EM sensors were useful for reconnaissance survey; an activity that is done at the strategic (early) phase of a mining exploration campaign, usually 1 or 2 years before exploring on the surface. He wanted to do tactical mining exploration that integrate quick airborne exploration in tandem with a surface exploration team. He planned to use a Cessna L19 (also known as O-1 Bird Dog). This quite small aircraft has only 2 seats in a row : the pilot seat and the mission specialist seat that is located behind the pilot seat. My boss was a genius; I was excited about his idea. Such aircraft was used for surveillance (spying) and indoctrination activities during the Vietnam War; it is small, but equipped with an oversized engine. You know, if you see the enemy sending an RPG towards you, you better climb-up as fast as possible. Since the area of exploration were mountainous, the aircraft need to climb reliably the mountain slopes. I was on that aircraft during the testing and debugging phases; I am not that brave and I was shivering during every flight with that aircraft, especially when we were climbing along a jaggy slope at low altitude during a partially cloudy day or during a windy day. I found out that following down the slope was even more frightening. I modified and adapted a portable EM sensor on the aircraft, under the supervision of my boss and of an aeronautic engineer. We end up with a light version of an airborne EM sensors, as shown in the picture above. The sensors look-like fat sticks affixed at the tip of the wings. It looks simple, but it is not.