ing, designated by the prefix RNAV; e.g., RNAV 5,  RNAV 1.  Note: The Performance-based Navigation Manual  (Doc 9613), Volume II contains detailed guidance  on navigation specifications.  NAVIGATIONAL AID- Any visual or electronic  device airborne or on the surface which provides  point-to-point guidance information or position data  to aircraft in flight.  (See AIR NAVIGATION FACILITY.)  (See NAVIGATION SPECIFICATION [ICAO].)  $_{ }$ 8/15/19 1/30/20  Pilot/Controller Glossary Pilot/Controller Glossary  (See NATIONAL BEACON CODE ALLOCATION  PLAN AIRSPACE.)  (See NONDIRECTIONAL BEACON.)  NEGATIVE- “No,” or “permission not granted,” or  “that is not correct.”  NBCAP AIRSPACE- NDB- NEGATIVE CONTACT- Used by pilots to inform  ATC that:  a.  Previously issued traffic is not in sight. It may  be followed by the pilot's request for the controller to  provide assistance in avoiding the traffic.  b.  They were unable to contact ATC on a  particular frequency.  NFDC- (See NATIONAL FLIGHT DATA CENTER.)  NFDD- (See NATIONAL FLIGHT DATA DIGEST.)  NIGHT- The time between the end of evening civil  twilight and the beginning of morning civil twilight,  as published in the Air Almanac, converted to local  time.  (See ICAO term NIGHT.)  NIGHT [ICAO]- The hours between the end of  evening civil twilight and the beginning of morning  civil twilight or such other period between sunset and  sunrise as may be specified by the appropriate  authority.  Note: Civil twilight ends in the evening when the  center of the sun's disk is 6 degrees below the  horizon and begins in the morning when the center  of the sun's disk is 6 degrees below the horizon.  NO GYRO APPROACH- A radar approach/vector  provided in case of a malfunctioning gyro-compass  or directional gyro. Instead of providing the pilot  with headings to be flown, the controller observes the  radar track and issues control instructions “turn  right/left” or “stop turn” as appropriate.  (Refer to AIM.)  NO GYRO VECTOR- (See NO GYRO APPROACH.)  NO TRANSGRESSION ZONE (NTZ)- The NTZ is  a 2,000 foot wide zone, located equidistant between  parallel runway or SOIA final approach courses, in  which flight is normally not allowed.  NONAPPROACH CONTROL TOWER- Author- izes aircraft to land or takeoff at the airport controlled  by the tower or to transit the Class D airspace. The  primary function of a nonapproach control tower is  the sequencing of aircraft in the traffic pattern and on  the landing area. Nonapproach control towers also  separate aircraft operating under instrument flight  rules clearances from approach controls and centers.  They provide ground control services to aircraft,  vehicles, personnel, and equipment on the airport  movement area.  NONCOMMON ROUTE/PORTION- That segment  of a North American Route between the inland  navigation facility and a designated North American  terminal.  NON-COOPERATIVE SURVEILLANCE- Any  surveillance system, such as primary radar, that is not  dependent upon the presence of any equipment on the  aircraft or vehicle to be tracked.  (See COOPERATIVE SURVEILLANCE.)  (See RADAR.)  NONDIRECTIONAL BEACON- An L/MF or UHF  radio beacon transmitting nondirectional signals  whereby the pilot of an aircraft equipped with  direction finding equipment can determine his/her  bearing to or from the radio beacon and “home” on or  track to or from the station. When the radio beacon is  installed in conjunction with the Instrument Landing  System marker, it is normally called a Compass  Locator.  (See AUTOMATIC DIRECTION FINDER.)  (See COMPASS LOCATOR.)  NONMOVEMENT AREAS- Taxiways and apron  (ramp) areas not under the control of air traffic.  PCG N-2 