Così, tanto per essere precisi:
OPS 1.990
Number and composition of cabin crew
(a) An operator shall not operate an aeroplane with a maximum approved passenger seating configuration of more
than 19, when carrying one or more passengers, unless at least one cabin crew member is included in the crew for the
purpose of performing duties, specified in the Operations Manual, in the interests of the safety of passengers.
(b) When complying with subparagraph (a) above, an operator shall ensure that the minimum number of cabin crew is
the greater of:
1. one cabin crew member for every 50, or fraction of 50, passenger seats installed on the same deck of the
aeroplane; or
2. the number of cabin crew who actively participated in the aeroplane cabin during the relevant emergency evacuation
demonstration, or who were assumed to have taken part in the relevant analysis, except that, if the maximum
approved passenger seating configuration is less than the number evacuated during the demonstration by at
least 50 seats, the number of cabin crew may be reduced by 1 for every whole multiple of 50 seats by which the
maximum approved passenger seating configuration falls below the certificated maximum capacity.
(c) The Authority may under exceptional circumstances require an operator to include in the crew additional cabin crew
members.
(d) In unforeseen circumstances the required minimum number of cabin crew may be reduced provided that:
1. the number of passengers has been reduced in accordance with procedures specified in the Operations Manual;
and
2. a report is submitted to the Authority after completion of the flight.
Come vedi, si parla sempre e solo di "passenger seating configuration", alias sedili, e viene anche citato il caso di crew ridotti, quando, come e perchè.