Helicomparator
IIRC the initiative to reduce from 19 to 18 in the AS332L came from Bond Helicopters (Engineering Director Tony Cox I believe) when they showed a reconfigured machine with some seats reversed to the UKOOA aircraft committee and the other operators (BIH and Bristow). UKOOA agreed that should be the standard along with a whole raft of modifications done on all types on a collective basis around that time, such as push out windows with integral water operated lighting, video briefing of passengers, ADELT beacons and other stuff like floor lighting. All operators fitted everything agreed, paid for by a time limited supplementary charge on each contract until the cost recovery was complete.