N
N |abbreviation| north
N1 |abbreviation| an engine low pressure compressor (and fan) rotation speed expressed as a percentage / 97% N1 is a typical value /
N2 |abbreviation| an engine high pressure compressor rotation speed
nacelle |noun| a streamlined housing for an engine / The ram air intake is located in a wing leading edge or an engine nacelle fairing. /
narrow |adjective| not wide / The narrow aisles of passenger aircraft makes it difficult to evacuate an aircraft quickly. / Opposite: wide, broad
NAS |abbreviation| national airspace system
NASA |abbreviation| National Aeronautics and Space Administration
national |adjective| belonging to a country / KLM is the national airline of the Netherlands. /
National Aeronautics and Space Administration |noun| a US organization for flight and space exploration. Abbreviation: NASA
national airspace system |noun| an integrated system of control and communications facilities that is responsible for ensuring the safe and efficient movement of aircraft through the national airspace of the US. Abbreviation: NAS
National Air Traffic Services |plural noun| the organization that is responsible for air traffic control at most UK airports. Abbreviation: NATS
NATS |abbreviation| National Air Traffic Services
nature |noun| 1. the world, especially plants, animals and their environment in general / Electricity is one of the fundamental forces of nature. / 2. sort or type / Action taken by the crew will depend on the nature of the emergency. / 3. the essential qualities of something / Magnesium is a fire hazard of unpredictable nature. /
nautical |adjective| referring to the sea / The terms pitch, roll and yaw are nautical in origin. /
nautical mile |noun| 1.852 kilometers / One knot is equal to one nautical mile per hour. / Abbreviation: nm. (NOTE: A nautical mile is precisely defined as the length of an arc on the Earth’s surface subtended by an angle of one minute at the center of the Earth.)
NAVAID |abbreviation| navigational aid
navigation |noun| the theory and practice of planning, controlling and recording the direction of an aircraft / The basis of air navigation is the triangle of velocities. /
navigation accuracy check |noun| the crew’s practice of crosschecking different navigation instruments and sources against each other in order to make sure their data is correct
Navigation Display |noun| one of the main pilot instruments which provides compass heading, navigational and weather radar return data; it is located in front of each pilot next to the PFD (Primary Flight Display). Abbreviation: ND
navigational |adjective| referring to navigation / The accuracy of modern navigational equipment is much greater than older systems. /
navigational aid |noun| a mechanical or electronic device designed to help a pilot navigate e.g DME (Distance Measuring Equipment), NDB (Non-Directional Beacon), ADF (Automatic Direction Finder), VOR (VHF Omnidirectional Range), ILS (Instrument Landing System: localizer and glideslope), VORTAC (VOR + Tacan), GPS (Global Positioning System), GNSS (Global Navigation Satellite System), RNAV (Area Navigation) / Any type of navigational aid but particularly electronic aids, for example ADF (automatic direction finding) and NDBs (non-directional beacons). / Abbreviation: NAVAID
navigational line |noun| same as position line
navigation lights |plural noun| lights on an aircraft consisting of a red light on the left wing tip, a green light on the right wing tip and a white light on the tail (NOTE: Navigation lights must be used between sunset and sunrise.)
navigation log |noun| written details of headings and times for a flight / The flight crew route flight plan is a composite document which also serves as a navigation log. /
ND |abbreviation| Navigation Display
NDB |abbreviation| non-directional beacon
necessary |adjective| needed or essential / A rich mixture is necessary at slow running. / - as necessary > when needed / Warnings, cautions and advisory messages are displayed only when necessary. /
necessity |noun| something that is necessary or very important / Student pilots should understand the necessity for treating thunderstorms with great respect. /
needle |noun| a thin metal pointer in an instrument / The needle indicated to zero. /
needle valve |noun| a valve formed of a tapered needle projecting into a small opening in a tube, etc., usually connected to a float, which provides fine adjustment of fluid flow / Atmospheric pressure will allow the capsule to expand, causing the needle valve to move into the opening thus reducing the flow of fuel. /
negative |adjective| 1. a value of less than 0 / In a reversing propeller, the propeller mechanism includes a removable ground fine pitch stop which enables the propeller to be set to a negative pitch. / 2. referring to an electric charge of the same sign as that of an electron - the negative terminal of a battery > the terminal of a battery marked with the symbol – and normally colored black rather than red 3. showing refusal - a negative answer > no; permission not granted; this is not correct; not capable / Are you going around? Negative. / 4. showing resistance or non-co-operation
negligible |adjective| small or unimportant to the extent that it is not worth considering / Atmospheric attenuation is negligible until the upper end of the UHF (ultra high frequency) band when it increases rapidly. / - negligible risk > almost no risk
neoprene |noun| a type of synthetic rubber
net |adjective| after all necessary deductions
net dry weight |noun| the basic weight of an engine without fluids and without accessories not essential for the engine to function
network |noun| 1. a complex interconnected group or system / A network of meteorological stations around the world exchange information. / 2. a system of lines or channels which cross each other / On a map, meridians of longitude and parallels of latitude form a network of lines called a graticule. / 3. a system of computers interconnected in order to share information
neutral |adjective|,|noun| 1. indicating an electrical charge which is neither positive nor negative 2. indicating the position of a switch or lever which leaves a system active but not engaged, e.g. an engine gear lever position in which the engine is disconnected from the driven parts 3. indicating the middle position of a control surface providing no aerodynamic effect other than that as part of the wing / After a turn, the auto-control will return the ailerons to neutral as the aircraft returns to straight flight. /
neutralize |verb| to cancel the effect of / Spillage from a lead acid battery may be neutralized by washing with a diluted solution of sodium bicarbonate. /
never-exceed speed |noun| a speed which must not be exceeded. Also called: Vne (Velocity Never Exceeded)
night rating |noun| an additional qualification gained from a course of training for night flying
nil |noun| nothing, zero
nimbo-stratus |noun| a cloud forming a low dense grey layer from which rain or drizzle often falls
nitrogen |noun| a colorless, odorless gas which makes up four fifths of the Earth’s atmosphere / Some aircraft have high pressure air or nitrogen bottles provided in the undercarriage and flap circuits for emergency lowering. / (NOTE: The atomic number of nitrogen is 7.)
nm |abbreviation| nautical mile
nocturnal |adjective| happening or appearing during the night / Because there is a requirement for a cold ground, a katabatic wind tends to be nocturnal, but if the slope is snow-covered, it can also occur during the day. /
no-entry sign |noun| an airport sign which indicates that a taxiway etc. is closed or unserviceable. A no-entry sign is a white rectangle on a red circular background
no-fly zone |noun| an area over which aircraft, especially those of another country, are forbidden to fly
no-go item |noun| a component or system on the Minimum Equipment List (MEL) which, if it is unserviceable, prevents the aircraft from being dispatched for a flight
no-show |noun| a passenger who is booked on a flight, but does not check in
noise |noun| 1. an unwanted signals within an electronic system / We’re getting a lot of noise on the tower frequency. / 2. a sound / What was that noise from the cabin? /
nominal |adjective| 1. not significant or not important - a nominal increase > a very small increase 2. named, specific / As an installed battery becomes fully charged by the aircraft generator, the battery voltage nears its nominal level and the charging current decreases. /
non- |prefix| not or no
non-directional beacon |noun| a radio beacon transmitting a signal by which the pilot can determine his or her bearing. Abbreviation: NDB
non-emergency evacuation |noun| the act of leaving the aircraft as a precautionary measure while the aircraft is not at its parking stand
non-essential |adjective| not necessary / In order to ensure the shortest possible take-off run, all non-essential equipment was removed. /
non-precision approach |noun| an instrument approach which uses horizontal guidance (Localizer, DME, VOR, NDB etc.), but not vertical guidance (glide-slope)
non-return valve |noun| a valve which allows a fluid to pass in one direction only / As the piston moves upwards in the cylinder, fluid is drawn in through a non-return valve. /
non-smoking area |noun| an area where smoking is not allowed
normal |adjective| referring to something which is usual and is to be expected - under normal conditions > when everything is as it usually is
normal room temperature |noun| the temperature regarded as comfortable for usual daily activity
north |noun| compass point 360°, the direction towards which the magnetic needle points on a compass / Fly towards the north. The wind is blowing from the north. / - north facing mountain side > the face of the mountain which looks towards the north - |adjective| 1. referring to areas or regions lying in the north, referring to the compass point 360° / the north coast of France / 2. the northern part of a region or country - |adverb| towards the north / The aircraft was heading north. /
northbound |adjective| traveling towards the north / a northbound flight /
north-east |noun| the direction between north and east / After take-off, the aircraft turned to the north-east. / - |adjective| 1. situated in the north-east / the north-east coast of England / 2. blowing from or coming from the north-east / a north-east wind / - |adverb| towards the north-east / We are heading north-east. /
north-easterly |adjective| 1. blowing from or coming from the north-east / A north-easterly wind was blowing. / 2. moving towards the north-east / Follow a north-easterly direction. /
north-eastern |adjective| referring to or situated in the north-east / the north-eastern part of the United States /
northerly |adjective| 1. situated towards the north / the most northerly point of a country / 2. blowing from or coming from the north - northerly airflow > airflow coming from the north / a northerly airflow from the polar regions / 3. moving towards the north / We are flying in a northerly direction. / - |noun| a wind which blows from the north
northern |adjective| referring to or situated in the north / the northern hemisphere /
northern hemisphere |noun| the area of the Earth to the north of the equator
North Pole |noun| the point which is furthest north on the earth / From the UK the aircraft flew over the North Pole to Vancouver. /
northward |adjective| going towards the north - |adverb| US same as northwards
northwards |adverb| towards the north / One of the aircraft was flying northwards. /
north-west |noun| the direction between north and west / The aircraft turned towards the north-west. / - |adjective| 1. situated in the north-west / the north-west coast of England / 2. blowing from or coming from the north-west / a north-west wind / - |adverb| towards the north-west / We are heading north-west. /
north-westerly |adjective| 1. blowing from or coming from the north-west / A north-westerly wind was blowing. / 2. moving towards or to the north-west / Follow a north-westerly direction. /
north-western |adjective| referring to or situated in the north-west / the north-western part of the United States /
north wind |noun| a wind blowing from or coming from the north (NOTE: A wind is named after the direction it comes from.)
nose |noun| the extreme forward end of the aircraft
nose cone |noun| the foremost part of the nose of a multi-engine aircraft which may house electronic equipment, but not an engine
nose dive |noun| an extremely steep descent by an aircraft front first
nose-dive |verb| to fall steeply with the front end pointing downwards
nose gear |noun| the nose wheel and supporting struts and linkages
nose-wheel |noun| the undercarriage wheel at the front of the aircraft.
NOSIG |abbreviation| no significant change for the next two hours in a METAR
no-smoking sign |noun| a sign, usually lit-up, warning passengers and crew that smoking is not allowed
NOTAM |abbreviation| Notice to Airmen
note |noun| 1. a brief message on a piece of paper / There’s a note on your desk. / 2. a brief comment made on paper about something that you are reading, listening to, or watching / Make notes while you watch the video recording. / 3. a short comment or explanation in a text, often at the end of a book or at the bottom of a page 4. a piece of paper money (NOTE: The US English is bill.) 5. a musical tone of definite pitch / The note of the engine changes as rpm (revolutions per minute) is increased. / - |verb| 1. to observe carefully, to take notice / Note that true north is always along a meridian. / 2. to write down / Note the time of departure on the log sheet. Note the time of any incident. / ‘…immediately you become unsure of your position, note the time and, if you are in touch with an ATC unit, especially a radar unit, you should request assistance’ [Civil Aviation Authority, General Aviation Safety Sense Leaflet]
notice |noun| 1. a written or spoken announcement 2. a formal warning or notification - to give notice > to inform an employee or employer in advance and in writing, of a termination to a period of employment / As a result of the accident, the instructor was given three months’ notice. / - the student pilot is grounded until further notice > the student pilot cannot fly again until told by those in authority that he or she can continue - |verb| to observe / While doing the pre-flight checks, Captain Smith noticed that there was a leak of hydraulic fluid from one of the brake cylinders. /
noticeable |adjective| catching the attention, easily noticed - a noticeable increase > an increase which is important enough to be observed / There was a noticeable improvement in the trainee’s recent exam results. /
notice board |noun| a usually wooden board in a corridor or classroom, etc., where information on paper can be displayed
Notice to Airmen |noun| a document giving information about changes to aeronautical facilities, services, procedures or hazards. NOTAM are available in the form of Pre-Flight Information Bulletins (PIB) using a live database. Abbreviation: NOTAM
notification |noun| the act of informing somebody about something / Notification of the new procedures will follow in a few days. She received notification that she had been accepted for the job. /
notify |verb| to inform / Students were notified of their exam results by post. The authorities must be notified of all in-flight incidents. /
nozzle |noun| a projecting part with an opening at the end of a pipe, for regulating and directing a flow of fluid / The nozzle of a portable fire extinguisher should be pointed at the base of the fire. /
nucleus |noun| the central part around which other parts are grouped / An atom consists of a nucleus with orbiting electrons. Condensation occurs on very small particles suspended in the air which are known as condensation nuclei. / (NOTE: The plural form is nuclei.)
null |noun| an instrument reading of zero / Nulls are used for direction sensing because they are better defined than the maximum. /
numerical |adjective| referring to numbers or digits
numerical value |noun| a number
numerous |adjective| very many, a lot / Large transport aircraft have numerous clearly-marked exits to facilitate rapid evacuation of passengers. Numerous refinements to the simple actuator will be found in use. /
nut |noun| a metal ring which screws on a bolt to hold it tight / Turn the nut anticlockwise to loosen it. /
