I always wonder, how many types of aircrafts can a cabin crewmember be qualified for? is there a limitation by say IATA, FAA or EASA?
I know very little about this, but in the US the regulations appear to say that cabin crew must be qualified by aircraft type and the details are part of the approved training program for each operator (airline).
(a) Any person identified by the certificate holder as a flight attendant on an aircraft in operations under this part must be trained and qualified in accordance with subparts N and O of this part.
§121.421 Flight attendants: Initial and transition ground training.
(a) Initial and transition ground training for flight attendants must include instruction in at least the following:
(1) General subjects—
(i) The authority of the pilot in command;
(ii) Passenger handling, including the procedures to be followed in the case of deranged persons or other persons whose conduct might jeopardize safety; and
(iii) Approved crew resource management initial training.
(2) For each airplane type—
(i) A general description of the airplane emphasizing physical characteristics that may have a bearing on ditching, evacuation, and inflight emergency procedures and on other related duties;
(ii) The use of both the public address system and the means of communicating with other flight crewmembers, including emergency means in the case of attempted hijacking or other unusual situations; and
(iii) Proper use of electrical galley equipment and the controls for cabin heat and ventilation.
(b) Initial and transition ground training for flight attendants must include a competence check to determine ability to perform assigned duties and responsibilities.
I couldn't see any limitation on the number of "airplane types" that a flight attendant can be qualified in, but the training is administered by the airline so if there is a limitation it may set by them rather than by the FAA. 121.427 requires recurrent training (but it doesn't say how often) and I assume that at some point a flight attendant who's qualified on multiple aircraft types could end up spending more time training than actually working on flights. That's unlikely to be something that the airline wants to happen.