An aeroplane subject operating under the visual flight rules (VFR) by day is subject to the following instrument carriage requirements:
The equipment must have an adjustable datum scale calibrated in millibars or hPa; an be calibrated in ft, except that, if a flight is conducted in a foreign country which measures FLs or altitudes in metres, the equipment must be calibrated in metres, or fitted with a conversion placard or device.
The equipment must be a direct reading magnetic compass; or both a remote indicating compass; and a standby direct reading magnetic compass.
There are no additional requirements.
Turn and Slip Indicator
(Aerial work ops only)
The equipment must display accurate time in hours, minutes and seconds. It must be fitted to the aircraft or immediately accessible to, the pilot for the duration of the flight.
The time instrument is often displayed on the OAT gauge shown below.
Outside Air Temperature
Aerial work ops from an aerodrome at which ambient air temperature is not available from ground-based instruments.)