Aeronautical Terms beginning with N

N1

Rotational speed of the low pressure compressor in a turbine engine.

N1,N2,N3

Spool speed expressed in percent rpm. N1 on a turboprop is the gas producer speed. N1 on a turbofan or turbojet engine is the fan speed or low pressure spool speed. N2 is the high pressure spool speed on engine with 2 spools and medium pressure spool on engines with 3 spools with N3 being the high pressure spool.

N2

Rotational speed of the high pressure compressor in a turbine engine.

Navigation Reference System (NRS)

The NRS is a system of waypoints developed for use within the United States for flight planning and navigation without reference to ground based navigational aids. The NRS waypoints are located in a grid pattern along defined latitude and longitude lines. The initial use of the NRS will be in the high altitude environment in conjunction with the High Altitude Redesign initiative. The NRS waypoints are intended for use by aircraft capable of point-to-point navigation.

Negative Torque Sensing (NTS)

A system in a turboprop engine that prevents the engine from being driven by the propeller. The NTS increases the blade angle when the propellers try to drive the engine.

Normal Operating Zone (NOZ)

The NOZ is the operating zone within which aircraft flight remains during normal independent simultaneous parallel ILS approaches.