WingX 2.0 User Manual - FAASafety.gov

Safety
Darkness increases the risk when flying. For example, emergency landing areas are not as easy to find,
instruments may be more difficult to read, objects that have fallen on the floor will be more difficult to find,
and mountains may be impossible to see on a moonless night. The risks and dangers associated with flying at
night are very well documented in many books and videos on the subject. Use WingX to determine the sunset
time, when it is starting to get dark, and when it probably might not be a good idea to be flying in the
mountains in a single-engine aircraft.
Legality
WingX displays six times – three are related to the sunrise and three are related to the sunset. While the actual
sunrise and sunset times are physical events, the other four times are associated with particular FARs with
which pilots should be familiar. In the following paragraphs, we’ll discuss all six times and how they relate to
regulatory requirements.
Sunrise and Sunset Times
One Federal Aviation Regulation (FAR) regarding sunrise and sunset times is:
FAR 91.209 - Aircraft lights
No person may:
(a) During the period from sunset to sunrise (or, in Alaska, during the period a prominent
unlighted object cannot be seen from a distance of 3 statute miles or the sun is more
than 6 degrees below the horizon) —
(1) Operate an aircraft unless it has lighted position lights;
(2) Park or move an aircraft in, or in dangerous proximity to, a night flight operations area
of an airport unless the aircraft—
(i) Is clearly illuminated;
(ii) Has lighted position lights; or
(iii) is in an area that is marked by obstruction lights;
* partial listing of the FAR
Therefore the WingX sunrise and sunset times define the times before which and after which, respectively, an
aircraft may not be moved on the surface (without the above-mentioned safeguards), or flown legally.
99