The flagship airline of Finland has declared that it is currently weighing passengers in addition to their luggage.
Finnair said the weigh-ins are "voluntary and anonymous" and will help to ensure the airline does not exceed the set maximum weight for a safe take-off.
Volunteer passengers will be weighed with their carry-on baggage, and only the customer service agent working at the measuring point will be able to see the total weight.
The collected data will not be linked in any way to a passenger's personal data, the airline said.
The voluntary weigh-ins have started taking place at the departure gates at Helsinki Airport.
The weight of the aircraft includes the weight of the plane itself, the fuel, checked baggage and cargo, onboard catering, water tanks - and passengers.
While airlines know the weight of all other aspects, the weight of passengers and their carry-on baggage is calculated using average weights provided by the Civil Aviation Authority (CAA).
The alternative option is for airlines to either use their own measurements or standard weights defined by the European Aviation Safety Authority EASA.
Since 2018, Finnair has used average weights determined by its own measurements, but the authorities require these figures to be updated every five years.
It said the time had come to collect new data to optimise the airline's aircraft balance calculations.
"In the previous measurements five years ago, a good number of volunteers wanted to participate in the weighing, and we hope to have a good sample of volunteers, both business and leisure travellers, also this time, so that we can get the most accurate information possible for important balance calculations," said Satu Munnukka, head of ground processes at Finnair.