Finnair has started to weigh passengers as they board their flights. This is something unheard of and hasn’t happened since the early parts of commercial aviation. The only reason you are really weighed in the current day is for very small commercial prop planes at small airports. Finnair runs an extensive fleet of large aircraft where you don’t have to weigh each passenger.
The reason for this weight-in isn’t to discriminate against passengers but to hopefully cut down on fuel costs by reducing the average weight of passenger calculations. To explain what’s going on you have to understand how estimated weights and balances are calculated to figure out how much fuel you need to put on a plane.
Currently any commercial flight uses an average weight figure to estimate the weight of the plane. For Finnair they currently use 84.6kg for a male, a female 66.5kg, and under-12 they use 30.7kg. This means that when the airline is calculating how much fuel they need they will use these numbers to see how much fuel they need. However if these numbers are more than what they actually need they ware wasting fuel and time by taking unnecessary fuel.
The European Aviation Safety Agency (EASA) sets these averages and Finnair is unable to change these figures. This Finnish airline has embarked to gain an exemption from EASA by proving that their figures are lower than the average and if approved will save millions in fuel costs.
A similar thing happened recently in the US with Hawaiian Airlines who was able to prove that they were overestimating most of their flights and was able to reduce fuel costs by hauling less fuel around.
If airlines were to weigh each passenger before they boarded and weigh their luggage to get more accurate numbers they would be able to take the perfect amount of fuel however that’s not wise. IT would be incredibly time-consuming to weight each passenger and their belongings and would increase boarding and wait times for aircraft. For this reason they use averages for their weight conversions and allows them to get extremely close to what the actual weight of the aircraft will be.