Distractions and problems can result from a flickering  light in the flight deck, such as anticollision lights, strobe  lights, or other aircraft lights which can cause flicker  vertigo. If continuous, the possible physical reactions can  be nausea, dizziness, grogginess, confusion, headaches, or  unconsciousness. The pilot should try to eliminate any light  source causing blinking or fl ickering problems in the fl ight  deck. A black-hole approach occurs when the landing is made  from over water or unlighted terrain on which runway lights  are the only sources of light. Without peripheral visual cues  to help, pilots have trouble orienting themselves relative to  Earth. The runway can seem out of position (downsloping or  upsloping) and, in the worst case, result in landing short of the  runway. If an electronic glideslope or visual approach slope  indicator (VASI) is available, it should be used. If navigation  aids (NAVAIDs) are unavailable, careful attention should be  given to using the flight instruments to assist in maintaining  orientation and a normal approach. If at any time the pilot is  unsure of his or her position or attitude, a go-around should  be executed. Bright runway and approach lighting systems, especially  where few lights illuminate the surrounding terrain, may  create the illusion of less distance to the runway. In this  situation, the tendency is to fly a higher approach. Also,  when flying over terrain with only a few lights, it makes the  runway recede or appear farther away. With this situation,  the tendency is common to fly a lower-than-normal approach.  If the runway has a city in the distance on higher terrain, the  tendency is to fly a lower-than-normal approach. A good  review of the airfield layout and boundaries before initiating  any approach helps the pilot maintain a safe approach  angle. Illusions created by runway lights result in a variety  of problems. Bright lights or bold colors advance the  runway, making it appear closer. Night landings are further  complicated by the difficulty of judging distance and the  possibility of confusing approach and runway lights. For  example, when a double row of approach lights joins the  boundary lights of the runway, there can be confusion where  the approach lights terminate and runway lights begin. Under  certain conditions, approach lights can make the aircraft seem  higher in a turn to final than when its wings are level. Night flying requires that pilots be aware of and operate within  their abilities and limitations. Although careful planning of  any flight is essential, night flying demands more attention  to the details of preflight preparation and planning. Preparation for a night flight should include a thorough  review of the available weather reports and forecasts with  particular attention given to temperature-dew point spread.  A narrow temperature-dew point spread may indicate the  possibility of ground fog. Emphasis should also be placed on  wind direction and speed, since wind effects on the aircraft  cannot be as easily detected at night as during the day. On night cross-country flights, appropriate aeronautical  charts should be selected, including the appropriate adjacent  charts. Course lines should be drawn in black to be more  distinguishable. Prominently lighted checkpoints along the prepared course  should be noted. Rotating beacons at airports, lighted  obstructions, lights of cities or towns, and lights from major  highway traffic all provide excellent visual checkpoints. The  use of a GPS with a lighted screen adds significantly to the  safety and efficiency of night fl ying. All personal equipment should be checked prior to fl ight to  ensure proper functioning. It is very disconcerting to fi nd at  the time of need that a flashlight does not work. All aircraft lights should be turned on momentarily and  checked for operation. Position lights can be checked for  loose connections by tapping the light fixture. If the lights  blink while being tapped, further investigation to determine  the cause should be made prior to fl ight. The parking ramp should be examined prior to entering the  aircraft. During the day, it is quite easy to see stepladders,  chuckholes, wheel chocks, and other obstructions, but at  night it is more difficult. A check of the area can prevent  taxiing mishaps. After the pilot is seated in the flight deck and prior to starting  the engine, all items and materials to be used on the fl ight  should be arranged in such a manner that they will be readily  available and convenient to use. Extra caution should be taken at night to assure the propeller  area is clear. Turning the rotating beacon on or fl ashing the  aircraft position lights serves to alert persons nearby to remain  clear of the propeller. To avoid excessive drain of electrical  current from the battery, it is recommended that unnecessary  electrical equipment be turned off until after the engine has  been started.  Starting, Taxiing, and Runup  Preparation and Prefl ight 12-8