CS 25.1457 Cockpit voice recorders

• ED Decision 2020/024/R found in: CS-25 Amdt 27 - Large Aeroplanes (Jan 2023)

CS 25.1457 Cockpit voice recorders ED Decision 2020/024/R (See [AMC 25.1457](#_DxCrossRefBm1709821754)) (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](#_DxCrossRefBm1709820691); (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] [Amdt 25/26]