# Commission Regulation (EU) No 965/2012 of 5 October 2012 laying down technical requirements and administrative procedures related to air operations pursuant to Regulation (EC) No 216/2008 of the European Parliament and of the Council, Division (a): Each flight crew member required to be on duty in the flight crew compartment shall wear a headset with boom microphone or equivalent. The headset shall be used as the primary device for voice communications with ATS:

Extent: E+W+S+N.I.

(1)when on the ground:
(i)when receiving the ATC departure clearance via voice communication; and
(ii)when engines are running;
(2)when in flight:
(i)below transition altitude; or
(ii)10 000 ft, whichever is higher;
and
(3)whenever deemed necessary by the commander.

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Source: https://www.legislation.gov.uk/eur/2012/965/annex/IV/division/subpart+b/division/section+1/division/catopmpa215/division/a (the official version)
Page: https://openlegislation.uk/eu-regulation-2012-965/annex-IV/division-subpart+b/division-section+1/division-catopmpa215/division-a
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.