CS 25.1457 Cockpit voice recorders
(See AMC 25.1457)
(a) Each cockpit voice recorder required by
the operating rules must be approved and must be installed so that it will
record the following:
(1) Voice communications transmitted from or
received in the aeroplane by radio.
(2) Voice communications of flight-crew
members on the flight deck.
(3) Voice communications of flight-crew
members on the flight deck, using the aeroplane’s interphone system.
(4) Voice or audio signals identifying
navigation or approach aids introduced into a headset or speaker.
(5) Voice communications of flight-crew
members using the passenger loudspeaker system, if there is such a system and
if the fourth channel is available in accordance with the requirements of
sub-paragraph (c)(4)(ii) of this paragraph.
(b) The recording requirements of sub-paragraph
(a)(2) of this paragraph must be met by installing a cockpit-mounted area
microphone, located in the best position for recording voice communications
originating at the first and second pilot stations and voice communications of
other crew members on the flight deck when directed to those stations. The
microphone must be so located and, if necessary, the pre-amplifiers and
filters of the recorder must be so adjusted or supplemented, that the
intelligibility of the recorded communications is as high as practicable when
recorded under flight cockpit noise conditions and played back. Repeated aural
or visual playback of the record may be used in evaluating intelligibility.
(c) Each cockpit voice recorder must be
installed so that the part of the communication or audio signals specified in
subparagraph (a) of this paragraph obtained from the following sources is
recorded on at least four separate channels:
(1) From each boom, mask, or hand-held
microphone, headset, or speaker used at the first pilot station.
(2) From each boom, mask, or hand-held
microphone, headset, or speaker used at the second pilot station.
(3) From the cockpit-mounted area microphone.
(4) From:
(i) each boom, mask, or handheld microphone,
headset or speaker used at the stations for the third and fourth crew members;
or
(ii) if the stations specified in subparagraph
(c)(4)(i) of this paragraph are not required or if the signal at such a
station is picked up by another channel, each microphone on the flight deck
that is used with the passenger loudspeaker system if its signals are not
picked up by another channel.
No channel
shall record communication or audio signals from more than one of the
following sources: the first pilot station, second pilot station,
cockpit-mounted area microphone, or additional crew member stations.
As far as is
practicable, all the sounds received by the microphones listed in
subparagraphs (c)(1), (2) and (4) of this paragraph must be recorded without
interruption irrespective of the position of the interphone-transmitter key
switch. The design must ensure that sidetone for the flight crew is produced
only when the interphone, public address system or radio transmitters are in
use.
(d) Each cockpit voice recorder must be installed
so that –
(1) (i) It
receives its electrical power from the bus that provides the maximum
reliability for operation of the cockpit voice recorder without jeopardising
service to essential or emergency loads; and
(ii) It remains powered for as long as possible
without jeopardising emergency operation of the aeroplane;
(2) If the recorder has a recording duration
of less than 25 hours, there is an automatic means to stop the recording
within 10 minutes after crash impact;
(3) There is an aural or visual means for
pre-flight checking of the recorder for proper operation;
(4) Any single electrical failure that is
external to the recorder does not disable both the cockpit voice recorder
function and the flight data recorder function;
(5) There is a means for the flight crew to
stop the cockpit voice recorder function upon completion of the flight in a
way such that re-enabling the cockpit voice recorder function is only possible
by dedicated manual action;
(6) It has an alternate power source:
—
that
provides at least 10 minutes of electrical power to operate both the recorder
and the cockpit-mounted area microphone; and
—
to
which the recorder and the cockpit-mounted area microphone are switched
automatically in the event that all other power to the recorder is interrupted
either by a normal shutdown or by any other loss of power; and
(7) If the recorder is deployable:
(i) It has an automatic deployment capability
that is engaged no later than when the aeroplane is airborne and that remains
engaged as long as the aeroplane is airborne;
(ii) The automatic deployment capability and
the emergency locator transmitter integrated in the deployable recorder cannot
be manually disengaged from the cockpit when the aeroplane is capable of
moving under its own power;
(iii) The deployment occurs upon the detection
of severe structural damage that causes the immediate break-up of the
aeroplane;
(iv) The deployment occurs upon the immersion
of the aeroplane in water;
(v) An assessment of the effects of
unintended deployment is made in accordance with the specifications of CS 25.1309;
(vi) Effects on persons other than aeroplane
occupants and on search-and-rescue services are taken into account when
assessing the unintended deployment failure condition;
(vii) There is no means to manually deploy the
recorder while the aeroplane is capable of moving under its own power; and
(viii) An alert is provided to the flight crew when
the flight recorder is no longer attached to the aeroplane.
(e) If the recorder is not deployable, the
container of the recording medium must be located and mounted so as to
minimise the probability of the container rupturing, the recording medium
being destroyed, or the underwater locating device failing as a result of any
possible combinations of:
(1) impact with the Earth’s surface;
(2) the heat damage caused by a post-impact
fire; and
(3) immersion in water.
If the
recorder is deployable, the deployed part must be designed and installed so as
to minimise the probability of the recording medium being destroyed or the
emergency locator transmitter failing to transmit (after damage or immersion
in water) as a result of any possible combinations of:
(1) the deployment of the recorder;
(2) impact with the Earth’s surface;
(3) the heat damage caused by a post-impact
fire; and
(4) immersion in water.
(f) If the cockpit voice recorder has an
erasure device or function, the installation must be designed to minimise the
probability of inadvertent operation and actuation of the erasure device or
function during crash impact.
(g) The container of the cockpit voice
recorder must –
(1) Be bright orange; however, if the recorder
is deployable, the surface that is visible from outside the aeroplane, when
the recorder is installed, may be of another colour;
(2) Have reflective tape affixed to its
external surface to facilitate locating it;
(3) Have, if the recorder is not deployable, an
underwater locating device on or adjacent to the container which is secured in
such a manner that they are not likely to be separated during crash impact;
(4) Have, if the recorder is deployable, an
integrated emergency locator transmitter that automatically starts emitting
upon deployment; and
(5) Be, if the recorder is deployable, able to
float on water and self-oriented so that the transmission of the emergency
signal is not impeded.
[Amdt
25/23]
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