See and Avoid—The Cornerstone of Aviation Safety

Written by Rich Hanson President's Perspective Column As seen in the May 2017 issue of Model Aviation.

The first recorded midair collision occurred on October 3, 1910. Frenchman René Thomas, flying an Antoinette IV monoplane, collided with British Army Capt. Bertram Dickson, ramming his Farman III biplane in the rear at the Milano Circuito Aereo Internazionale meeting held in Milan, Italy. Both pilots survived, but Bertram was badly injured and never flew again. This incident revealed the need for a set of rules that separate aircraft in flight, and the basic concept that airmen should see and avoid one another as they transit through the airspace was born. Throughout the years, more rules have been added to create a set of Visual Flight Rules (VFR) that establish the rules of the road that pilots follow when flying outside of meteorological conditions. VFR conditions are said to exist when the prevailing cloud layer is at least 1,000 feet above the ground and horizontal visibility is at least 1 statute mile. For our purposes, modelers should avoid flying whenever the view of their aircraft is obscured by low clouds, fog, smoke, haze, or any other condition that prevents a clear view of the aircraft, the airspace, and the surrounding area in which the model aircraft is being flown. Although at times imperfect, the concept that pilots should see and avoid one another to evade collision has become the cornerstone of aviation safety. Airmen in flight are taught to continually scan the airspace ahead, above, below, and as much as possible, to the side and behind for other aircraft that could create an airspace conflict. A modeler should similarly scan the airspace in all directions to detect other aircraft and obstructions that might create a collision hazard. The techniques for seeing and avoiding other aircraft when a pilot is outside the aircraft observing the airspace from the ground is slightly different from those of a pilot observing from inside of the cockpit; however, the basic principles are the same. The perspective from the ground presents some challenges for an unmanned aircraft pilot, but also some advantages. Barring any tall trees or other obstacles surrounding the flying site that might block a pilot’s view, an observer from the ground often has an unobstructed 360° view of the surrounding airspace. And, unlike manned aircraft, an unmanned aircraft pilot can often hear approaching aircraft. The greatest challenge to observers on the ground is establishing a three-dimensional perspective between aircraft in the air. The detection and avoidance techniques for ground-based pilots are slightly different. There are five central principles to keep in mind. Vigilance must be maintained by each person operating an aircraft (whether model or manned) to see and avoid other aircraft. Whenever a potential conflict arises between model aircraft and manned aircraft, the pilot of a model aircraft must always give way to the manned aircraft and maneuver to increase separation. This could necessitate landing the model aircraft to clear the airspace. The pilot of a model aircraft must never assume that the pilot of a manned aircraft can see the model or will perform any maneuver to avoid the model’s flight path. Visual contact with the model aircraft must be maintained without enhancement and all model aircraft must remain clear of clouds, smoke, or any other obstruction to the line of sight. A modeler should never place any consideration for the well-being of the model aircraft above the safety of manned aircraft. This might mean sacrificing the model aircraft to avoid a near miss or collision.  Using a spotter to assist in monitoring the airspace is also an important tool model pilots should consider when operating in crowded, noisy, or high-density environments. When selecting a spotter, a pilot should ensure that the individual has sufficient visual acuity to monitor the environment and be mature enough to take this responsibility seriously.  Model aircraft flying must not only be safe, it must be perceived to be safe by the greater manned aviation community. Modelers must continually demonstrate their respect for the safety of manned aircraft by remaining vigilant and well clear of other aircraft. More information and detailed guidance on the responsibilities and techniques for seeing and avoiding other aircraft can be found in AMA Document #540-D. -Rich Hanson [email protected]