1 There are various conditions in which one part of the body overgrows others because of a genetic or congenital reason. An example of such a reason that would cause swollen legs is Klippel-Trenaunay syndrome.  Disuse edema â Not using a limb causes changes in blood flow and return to and from that limb.
A non-directional (radio) beacon (NDB) is a radio transmitter at a known location, used as an aviation or marine navigational aid. bearing is a line passing through the station that points in a specific direction, such as 270 degrees (due West). NDB bearings provide a charted, consistent method for defining paths aircraft can fly. In this fashion, NDBs can, like VORs, define  airways  in the sky.
NDBs used for aviation are standardised by ICAO Annex 10 which specifies that NDBs be operated on a frequency between 190 kHz and 1750 kHz, although normally all NDBs in North America operate between 190 kHz and 535 kHz. Each NDB is identified by a one, two, or three-letter Morse code callsign.