instrument runway
instrument runway
i. Non-Precision approach runway. An instrument runway served by visual aids and a nonvisual aid providing at least directional guidance adequate for a straight-in approach.
ii. Precision approach runway category I. An instrument runway served by an ILS (instrument landing system) and/or an MLS (microwave landing system) and visual aids intended for operations with a decision height not lower than 200 ft (60 m) and a runway visual range of the order of 800 m (2600 ft). (When RVR is not available, 0.5 statute miles ground visibility is substituted.) Rotorcraft visibility limits may be half those published for airplanes.
iii. Precision approach runway category II. An instrument runway served by an ILS and/or an MLS and visual aids intended for operation with a decision height lower than 200 ft (60 m) but not lower than 100 ft (30 m) and a runway visual range not less than 400 m (1200 ft). Rotorcraft visibility limits may be lower than those published for airplanes.
iv. Precision approach runway category III. An instrument runway served by an ILS to and along the surface of the runway and intended for operations down to an RVR (runway visual range) of the order of 200 m (600 ft) (no decision height is applicable), using visual aids during the final phase of landing; or intended for operations down to an RVR of the order of 50 m (150 ft) (no decision height is applicable), using visual aids for taxiing; or intended for operations without reliance on visual reference for landing or taxiing. The visual aids need not necessarily be matched to the scale of the nonvisual aids provided. The criterion for the selection of visual aids is the condition under which operations are intended to be conducted.