Document ID: chunk:federal_register_of_legislation:F2007L04706:body:0:p2
Version: federal_register_of_legislation:F2007L04706
Segment Type: other
Provision Reference: 
Character Range: 2787–5652

orange or bright yellow;

(b) reflective tape must be affixed to the external surface of the cockpit voice recorder container to facilitate its location under water.

3 Installation

       3.1Each cockpit voice recorder must be installed so that:

(a) the part of the signals mentioned in paragraph 2.2 obtained from each of the following sources is recorded on a separate channel:

 (i) for the first channel, from each microphone and headset used at the first pilot station;

 (ii) for the second channel, from each microphone and headset used at the second pilot station;

 (iii) for the third channel, from the flight deck mounted area microphone;

 (iv) for the fourth channel, from each microphone and headset used at the station for the third and fourth crew members;

 (v) if the stations in sub-subparagraph (iv) of this paragraph are not required, from each microphone and headset used at other flight deck stations having audio selection and transmit facilities;

 (vi) if the stations in sub-subparagraphs (iv) and (v) of this paragraph are not required, from each microphone on the flight deck that is used with the passenger address system, if its signals are not recorded on another channel;

(b) all sounds received by the microphones listed in sub-subparagraphs 3.1 (a) (i), (ii), (iv) and (v) must be recorded, irrespective of the position of the Radio Transmission/Intercommunication Selector switch (this configuration for microphones is commonly called "hot"), and:

 (i) the wiring must be such that side tone is produced only when Radio Transmission or Intercommunication is selected; and

 (ii) impedances and signal levels must be selected to avoid unwanted coupling between the microphone and headset circuits listed in sub-subparagraphs 3.1 (a) (i), (ii), (iv) and (v); and

 (iii) the gain should be adjusted such that for the microphones listed in sub‑subparagraphs 3.l (a) (i), (ii), (iv) and (v), the microphone signal exceeds the level of the headset side tone signal from other sources on a high percentage of occasions.

Note   This paragraph does not apply to hand-held microphones incorporating an ON/OFF switch. For such microphones, the sounds received need only be recorded when the switch is selected ON.

       3.2The flight deck mounted area microphone referred to in sub-subparagraph 3.1 (a) (iii) must be located and mounted in a position to pick up all the general cockpit sounds and the flight crew speech. The preamplifiers and filters must be so adjusted or supplemented, that the intelligibility of the recorded signals is as high as practical or when recorded under flight noise conditions, and played back.

Note   The most desirable location for the microphone is in a central position forward of a vertical plane orientated laterally through the pilots and co-pilots normal sitting positions. The presence and