Decoding the Design of In-Flight Seat Belts
atlasobscura.comI'd add that as a tall person - The acceptability of reclining your seat should also have to do with the height of the person behind you.
Three point harness common in business class longhaul. It comes with the lieflat seat designs.
I think part of the rationale is that you have more space for your head to pick up speed before it smushes into what's ahead.
Back in cattle-class, there just isn't much space for that acceleration.
I always assumed that it was because the main threat the seatbelts are trying to deal with were bad turbulence.
In such a scenario, if the plan rapidly drops and you're sat, the 2-point belt at the waist will keep you on your seat. If you're lying flat and you have the same belt you'll probably just sandwich your head against your knees or worse - especially if you're lying on your side or back!
I never checked to see if there was any validity to my thoughts though.
I wouldn't think it is really 'acceleration', just mass continuing at the same speed, when the aircraft and seat surrounding it might stop or change direction more suddenly. Relative speed change, but deceleration or change of aircraft speed, not acceleration of your head?
Better survival rates at the tail. More lemon scented towels up front.
Seat belts on passenger jets would be better described as "cargo restraints".