According to Schedule 4 of the UK ANO: Aeroplanes when flying at night for purposes other than public transport shall carry:
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(i) Equipment for displaying the lights required by the Rules of the Air.
(ii) Electrical equipment, supplied from the main source of supply in the aircraft, to
provide sufficient illumination to enable the flight crew properly to carry out their
duties during flight.
(iii) Unless the aircraft is equipped with radio, devices for making the visual signal
specified in the Rules of the Air as indicating a request for permission to land.
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(i) (a) In the case of a helicopter or gyroplane, a slip indicator.
(b) In the case of any other flying machine either:
(aa) a turn indicator and a slip indicator; or
(bb) a gyroscopic bank and pitch indicator and a gyroscopic direction indicator.
(ii) A sensitive pressure altimeter adjustable for any sea level barometric pressure which
the weather report or forecasts available to the commander of the aircraft indicate is
likely to be encountered during the intended flight.