NCO.IDE.H.120 Operations under VFR – flight and navigational instruments and associated equipment

INTEGRATED INSTRUMENTS

(a)Individual equipment requirements may be met by combinations of instruments, by integrated flight systems or by a combination of parameters on electronic displays. The information so available to each required pilot should not be less than that required in the applicable operational requirements, and the equivalent safety of the installation should be approved during the type certification of the rotorcraft for the intended type of operation.

(b)The means of measuring and indicating turn and slip, rotorcraft attitude and stabilised rotorcraft heading may be met by combinations of instruments or by integrated flight director systems, provided that the safeguards against total failure, inherent in the three separate instruments, are retained.

MEANS OF MEASURING AND DISPLAYING MAGNETIC HEADING The means of measuring and displaying magnetic direction should be a magnetic compass or equivalent.

MEANS OF MEASURING AND DISPLAYING THE TIME A means of measuring and displaying the time in hours, minutes and seconds may be a wrist watch capable of the same functions.

CALIBRATION OF THE MEANS OF MEASURING AND DISPLAYING PRESSURE ALTITUDE The instrument measuring and displaying pressure altitude should be of a sensitive type calibrated in feet (ft), with a sub-scale setting, calibrated in hectopascals/millibars, adjustable for any barometric pressure likely to be set during flight.

SLIP The means of measuring and displaying slip may be a slip string for operations under VFR.

CALIBRATION OF THE INSTRUMENT INDICATING AIRSPEED

(a)The instrument indicating airspeed should be calibrated in knots (kt).

(b)In the case of rotorcraft with an MCTOM below 2 000 kg, calibration in kilometres per hour (km/h) or in miles per hour (mph) is acceptable when such units are used in the AFM.

STABILISED HEADING Stabilised direction should be achieved for VFR flights by a gyroscopic direction indicator, whereas for IFR flights, this should be achieved through a magnetic gyroscopic direction indicator.

MEANS OF PREVENTING MALFUNCTION DUE TO CONDENSATION OR ICING The means of preventing malfunction due to either condensation or icing of the airspeed indicating system should be a heated pitot tube or equivalent.