Page 402 - UK Air Operations Regulations 201121

Part CAT - ANNEX IV - Commercial Air Transport Operations

(6) is appropriately illuminated during all phases of operation; and
(7) is associated with a means to alert the flight crew when operating under its
dedicated power supply, including when operated by emergency power.
(g) An alternate source of static pressure for the means of measuring altitude, airspeed and
vertical speed.
(h) Whenever two pilots are required for the operation, a separate means for displaying for the
second pilot:
(1) Barometric altitude;
(2) Indicated airspeed;
(3) Vertical speed;
(4) Slip;
(5) Attitude; and
(6) Stabilised heading.
(i) For IFR operations, a chart holder in an easily readable position that can be illuminated for
night operations.
CAT.IDE.H.130(a)(3) GM1 Operations under IFR — flight and navigational instruments and associated equipment
ALTIMETERS
Altimeters with counter drum-pointer or equivalent presentation are considered to be less susceptible
to misinterpretation for helicopters operating above 10 000 ft.
CAT.IDE.H.130(e) AMC1 Operations under IFR or at night — flight and navigational instruments and associated equipment
MEANS OF INDICATING FAILURE OF THE AIRSPEED INDICATING SYSTEM’S MEANS OF
PREVENTING MALFUNCTION DUE TO EITHER CONDENSATION OR ICING
A combined means of indicating failure of the airspeed indicating system’s means of preventing
malfunction due to either condensation or icing is acceptable provided that it is visible from each flight
crew station and that there it is a means to identify the failed heater in systems with two or more
sensors.
CAT.IDE.H.130(f)(6) AMC1 Operations under IFR or at night — flight and navigational instruments and associated equipment
ILLUMINATION OF STANDBY MEANS OF MEASURING AND DISPLAYING ATTITUDE
The standby means of measuring and displaying attitude should be illuminated so as to be clearly
visible under all conditions of daylight and artificial lighting.
CAT.IDE.H.130(i) AMC1 Operations under IFR or at night — flight and navigational instruments and associated equipment
CHART HOLDER
An acceptable means of compliance with the chart holder requirement is to display a pre-composed
chart on an electronic flight bag (EFB).
CAT.IDE.H.135 Additional equipment for single-pilot operation under IFR
Helicopters operated under IFR with a single-pilot shall be equipped with an autopilot with at least
altitude hold and heading mode.
CAT.IDE.H.145 Radio altimeters
(a) Helicopters on flights over water shall be equipped with a radio altimeter capable of
emitting an audio warning below a pre-set height and a visual warning at a height
selectable by the pilot, when operating:
(1) out of sight of the land;
(2) in a visibility of less than 1 500 m;
(3) at night; or
(4) at a distance from land corresponding to more than three minutes at normal cruising
speed.
CAT.IDE.H.145 AMC1 Radio altimeters
AUDIO WARNING DEVICE
(a) The audio warning should be a voice warning.
(b) The audio warning may be provided by a helicopter terrain awareness and warning system
(HTAWS).
CAT.IDE.H.145 AMC2 Radio altimeters
RADIO ALTIMETER DISPLAY
The radio altimeter should be of an analogue type display presentation that requires minimal
interpretation for both an instantaneous impression of absolute height and rate of change of height.
CAT.IDE.H.145 GM1 Radio altimeters
AUDIO-VOICE-ALERTING DEVICE
(a) To be effective, the voice warning alert should be distinguishable from other warnings and
should contain a clear and concise voice message.
(b) The warning format should meet the following conditions:
(1) the warning should be unique (i.e. voice);
(2) it should not be inhibited by any other audio warnings, except by higher priority alerts
such as helicopter terrain awareness and warning system (HTAWS); and
(3) the urgency of the warning should be adequate to draw attention but not such as to
cause undue annoyance during deliberate descents through the datum height.
(c) The criteria above can be satisfactorily met if the warning format incorporates all of the
following features:
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