CS 23.2555 Installation of recorders (e.g. cockpit voice recorders and flight data recorders)

If recording is required by the operating rules, the system:

(a)is installed so as to ensure accurate and intelligible recording and safeguarding of the required data, also in conditions encountered during crash, water immersion or fire;

(b)is powered by the most reliable power source and remains powered for as long as possible without jeopardising service to essential or emergency loads and emergency operation of the aeroplane;

(c)includes features to facilitate the localisation of a memory medium after an accident; and

(d)is installed so that it automatically records when the aeroplane is capable of moving under its own power.