Almost everything that gets onto a commercial plane — fuel, checked-in baggage, cargo and meals — is weighed. For passengers and their cabin bags, most airlines use average data.
But Finland’s national carrier Finnair said Friday that it started asking passengers this week voluntarily and anonymously hop onto a scale with their hand luggage at the country’s main airport in Helsinki, the airline said Friday. The aim is to get their own figures.
“We will need data for both winter season and for summer season — in winter season people typically have heavier clothing, which impacts weights,” Finnair spokeswoman Päivyt Tallqvist told The Associated Press, adding that the survey would last until May.
Passengers boarding onto European and long-haul flights won’t be “penalized for their weight,” and “the numbers are kept discreet, away from prying eyes,” she added.
I think it can be compensated for to some small degree. But… A deeper explanation is needed.
A plane has a center of mass (or gravity) which is the gravity balance point of the plane. It also has a center of lift which is like the center of gravity but for the lift force of the wing. See pic:
If the center of lift and center of gravity aren’t in the same horizontal location along the length of the plane, the plane has a net force that rotates the nose up or down.
It’s like if you had a yard stick and balanced it on your finger. And then added a weight somewhere between your finger and one end. The yard stick will start to rotate (tilt).
The horizontal stabilizer applies a force as well, and it is trimmed to balance the other forces and set the angle of attack (pitch) of the plane. The elevator allows momentary adjustment of pitch.
I may not describe this perfectly but… When a plane has too much weight towards the rear, it will be unstable (and dangerous) to fly. When a plane has too much weight towards the nose it will be somewhat sluggish but stable.
Balancing nose heavy is preferable to tail heavy in general due to the stability issue. A little bit of tail heavy is a bit dangerous and a bit of nose heavy is no big deal. I think another factor is that the tendency of a plane to pitch up could result in aerodynamic stall (loss or lift). Of course, if a plane is too nose-heavy, you can’t climb.
Front to back balance is really important to how the plane handles. Side to side balance matters but in terms of passengers / cargo, they’re more narrowly distributed about the center of the plane compared to their distribution front to back.
https://www.boldmethod.com/learn-to-fly/performance/what-effect-does-center-of-gravity-have-on-your-airplane-performance/
Oh man I was just trying to make a pithy comment, now you have me actually learning stuff?