Photo: Rhett RedelingsOn a recent United Airlines flight I was surprised to see that their new planes are equipped not just with lap belts, but shoulder restraints as well.
This just cannot make any sense.
First, planes virtually never crash. Second, when they do crash, it is unlikely that a shoulder restraint will be the deciding factor in whether you survive. Many crashes have an “all or nothing” flavor to them, with no chance at survival or almost everyone surviving.
Third, the evidence from car crashes suggests that lap belts are about 85 percent as effective as lap and shoulder belts — and a car crash is just the sort of impact where you might think a shoulder belt would be most useful because it keeps occupants from smashing into the windshield or steering wheel.
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Turbulence my good man…the purpose of the safety belts is also to prevent injuries caused by turbulence.
It probably serves two functions, not necessarily safety-oriented.
1) It likely makes passengers feel snugger and safer, regardless of whether or not they actually ARE.
2) Flight attendants, as part of their jobs, have to check to see if people are buckled in and remind them to do it if they haven’t. It’s much easier to tell if someone’s buckled in on a first glance if the belt goes across their shoulder.
A shoulder strap might keep you from smacking your head into the seat in front of you during turbulence. Not saying the loss of mobility would be worth it, but that’s probably the logic.
This would also have the secondary effect of preventing the obese from flying.
The reason for the shoulder belts might be apparent if you look at whether a significant number of crash victims die of broken necks or head injuries despite being restrained by a lap belt.
An interesting corrolary is: Why do the flight attendant seats have shoulder straps?
Otto- turbulence is up and down motion, the lap belt would do enough to hold you in place for this kind of motion.
I agree with Mr. Levitt, this doesn’t make sense in practice. Heck, airplanes are uncomfortable enough without putting extra restraints on us.
Finance, my good man. United engineers have routinely scoured salvage yards for premium seat belts and virtually all cars now have shoulder restraints. Their current crop of lap belts (stockpiled in 1971) is dwindling and can only be replaced with “modern” technology.