locate wires is by looking for the support structures. However,  pilots should review the most current hazard maps with  known wire locations before night flights. on the other hand, is flying away from aircraft 3, as indicated  by the white position light. In order to see other aircraft more clearly, regulations require  that all aircraft operating during the night hours have special  lights and equipment. The requirements for operating at night  are found in Title 14 of the Code of Federal Regulations (14  CFR) part 91. In addition to aircraft lighting, the regulations  also provide a definition of night flight in accordance with  14 CFR part 91, currency requirements, fuel reserves, and  necessary electrical systems. Illusions give false impressions or misconceptions of actual  conditions; therefore, pilots must understand the type of  illusions that can occur and the resulting disorientation.  Although the eye is the most reliable of the senses, some  illusions can result from misinterpreting what is seen; what  is perceived is not always accurate. Even with the references  outside the cockpit and the display of instruments inside,  pilots must be on guard to interpret information correctly. Relative motion is the falsely perceived self-motion in  relation to the motion of another object. The most common  example is as follows. An individual in a car is stopped at a  traffic light and another car pulls alongside. The individual  who was stopped at the light perceives the forward motion  of the second car as his or her own motion rearward. This  results in the individual applying more pressure to the brakes  unnecessarily. This illusion can be encountered during flight  in situations such as formation flight, hover taxi, or hovering  over water or tall grass. Position lights enable a pilot to locate another aircraft, as  well as help determine its direction of flight. The approved  aircraft lights for night operations are a green light on the  right cabin side or wingtip, a red light on the left cabin side  or wingtip, and a white position light on the tail. In addition,  flashing aviation red or white anticollision lights are required  for all flights, if equipped on the aircraft and in an operable  condition (in accordance with 14 CFR Section 91.209(b),  which aids in the identification during night conditions).  These flashing lights can be in a number of locations but are  most commonly found on the top and bottom of the cabin.  Figure 12-7  shows examples of aircraft lighting. By  interpreting the position lights on other aircraft, the pilot in  aircraft 3 can determine whether the aircraft is flying in the  opposite direction or is on a collision course. If a red position  light is seen to the right of a green light, such as shown by  aircraft 1, it is flying toward aircraft 3. A pilot should watch  this aircraft closely and be ready to change course. Aircraft 2,  Confusion with ground lights occurs when a pilot mistakes  ground lights for stars. The pilot can place the helicopter  in an extremely dangerous flight attitude if he or she aligns  it with the wrong lights. In  Figure 12-8A , the helicopter is  aligned with a road and not with the horizon. Isolated ground  lights can appear as stars and could lead to the illusion that  the helicopter is in a nose-high attitude. When no stars are visible because of overcast conditions,  unlighted areas of terrain can blend with the dark overcast to  create the illusion that the unlighted terrain is part of the sky  in  Figure 12-8B.  In this illusion, the shoreline is mistaken for  the horizon. In an attempt to correct for the apparent nose- high attitude, a pilot may lower the collective and attempt  to fly “beneath the shore.” This illusion can be avoided by  referencing the flight instruments and establishing a true  horizon and attitude. At night, an aircraft or helicopter may appear to be moving  away when it is actually approaching. If the pilot of each  aircraft has the same assumption, and the rate of closure  is significant, by the time each pilot realizes his or her  own error in assumption, it may be too late to avoid a  mishap. This illusion is called reversible perspective and  is often experienced when a pilot observes another aircraft  Reversible Perspective Illusion Confusion with Ground Lights Relative-Motion Illusion Visual Illusions Aircraft Lighting Figure 12-7.  Aircraft position lights.  12-6