Document ID: chunk:federal_register_of_legislation:F2007L04706:body:0:p3
Version: federal_register_of_legislation:F2007L04706
Segment Type: other
Provision Reference: 
Character Range: 5386–8337

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 location of flight deck loudspeaker(s) and the strength of the signals from these speakers must be considered when determining the optimum location for the microphone, so that other signals are not obliterated.

       3.3The quality of the recording on each channel must be as high as practicable. Before approval is given for each first type of aircraft/recorder system combination the quality must be established by play back of in-flight recorded information in accordance with Appendix I.

       3.4Each cockpit voice recorder must be installed so that:

(a) it receives its electrical supply from the bus that provides the maximum reliability for operation of the cockpit voice recorder without jeopardising service to essential or emergency loads; and

(b) there is a means of monitoring the cockpit voice recorder for proper operation, as part of the flight deck preflight procedure; and

(c) there is an automatic means to simultaneously stop the recorder and prevent any erasure feature from functioning, within 10 minutes after crash impact.

       3.5The cockpit voice recorder must be installed as far to the rear of the aircraft as possible, consistent with reasonable maintenance access, in a position to minimise the probability of damage from crash impact and subsequent fire.

Note   It need not be outside the pressurised compartment but the probability of damage from aft mounted engines, baggage, cargo and structural collapse must be minimised.

       3.6Facilities must be provided on the flight deck for erasure of the record on the ground after the aircraft has come to a stop at the completion of the flight. The installation must be designed to prevent in-flight erasure and to minimise inadvertent erasure during crash impact.

Appendix I

Cockpit voice recorder

Flight test

1 Introduction

      1.1 First of type aircraft/recorder combinations must be flight tested and the recording, so obtained, must be analysed. The test and analysis must demonstrate adequate recording quality during all normal regimes of flight including taxiing, take-off, cruise, approach and landing. For helicopters, hover and auto-rotation should be included.

      1.2 Since the duration of the recording is limited to 30 minutes, the CVR circuit breaker should be tripped between each test phase and at the end of the landing run.

      1.3 If time permits, systems which generate sounds on the flight deck, and which might not otherwise be used during the test flight, should be operated with appropriate announcements.

      1.4 This Appendix provides guidance for flight testing both aircraft and helicopters. It may need to be adapted to suit the particular