Why aren’t car-like 3 point seatbelts used in planes?
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1. Car crashes are often unexpected. Airplane crashes are not.
2. The three point belt is designed to stop the rapid acceleration and deceleration caused by a sudden and unexpected crash.
3. The brace position in an aircraft is more likely to save your neck than a three point belt, reducing the chance of whiplash.
There is extensive research on maximizing survival rates and minimizing injury rates among passengers. Unless the aircraft is completely demolished or turns into a fireball there is a good chance you’re going to survive and a correctly assumed brace position will maximize your chances of doing that with minimal injuries.
You’re free to search for the papers on such accidents (like the Hudson river miracle or Scandinavian flight 751).
1. Car crashes are often unexpected. Airplane crashes are not.
2. The three point belt is designed to stop the rapid acceleration and deceleration caused by a sudden and unexpected crash.
3. The brace position in an aircraft is more likely to save your neck than a three point belt, reducing the chance of whiplash.
There is extensive research on maximizing survival rates and minimizing injury rates among passengers. Unless the aircraft is completely demolished or turns into a fireball there is a good chance you’re going to survive and a correctly assumed brace position will maximize your chances of doing that with minimal injuries.
You’re free to search for the papers on such accidents (like the Hudson river miracle or Scandinavian flight 751).
1. Car crashes are often unexpected. Airplane crashes are not.
2. The three point belt is designed to stop the rapid acceleration and deceleration caused by a sudden and unexpected crash.
3. The brace position in an aircraft is more likely to save your neck than a three point belt, reducing the chance of whiplash.
There is extensive research on maximizing survival rates and minimizing injury rates among passengers. Unless the aircraft is completely demolished or turns into a fireball there is a good chance you’re going to survive and a correctly assumed brace position will maximize your chances of doing that with minimal injuries.
You’re free to search for the papers on such accidents (like the Hudson river miracle or Scandinavian flight 751).
My airplane has a 3 point seatbelt. It’s pretty much identical to what you would find in a car
My airplane has a 3 point seatbelt. It’s pretty much identical to what you would find in a car
My airplane has a 3 point seatbelt. It’s pretty much identical to what you would find in a car
In short, as a three-point harness adds proportionally less safety in an airplane as it does in a car, and a proportionally higher cost. The two-point seatbelt provides a very good protection even for fairly high impacts, despite the simplicity and very low weight (mostly of the two very strong mounting points of the seatbelt)
There are two main reasons:
1. Limited added safety from more complex belt, due to different nature of crashes. A typical airplane crash rarely comes as a full surprise. Rather, in most cases there is even time to teach and train the proper brace position (for example, prior to a suspected-to-be bad landing due to faulty landing gear or during the time between all engines failing and the inevitable hard landing to land or water). When implemented correctly, the brace position already suppresses the impact forces faced by the head and the torso, as one leans forward prior to impact rather than letting the head hit the seat ahead at speed (which we know to work based on past crashes, where the two-point seatbelt combined with a brace has been very effective at reducing both fatalities and injuries). A typical car crash comes comparably out of blue, leaving too little time to similarly brace for impact. Additionally, in a car that is crashing, there is much less space in front of you to be had before hitting something very hard*, like the steering wheel or in modern days the airbags (the airbags are very hard to hit, they are not soft cushioned bags of air but rather very taut and nearly solid bags of air; they provide, however, a less angular surface to collide than, say, steering wheel or the B-pilar).
2. It would increase the cost a lot, both initially and during use. A three-point seatbelt would need a third sturdy mounting point up top of the cabin, which would need a major redesign of all airplane interiors, and would also likely add plenty of extra weight per seat, increasing the fuel usage per flight. (*The backrests of regular airplane seats are not sufficiently strong for this purpose, as they are designed to flex upon impact to soften the impact forces of the person behind you, and also impact tested for this. And, neither is the bottom of the overhead compartments strong, not by a long shot. The impact forces taken by the seatbelts are massive, tens of times of your bodyweight. A two-point harness carries these loads conveniently to the floor of the aircraft via the fairly substantial pieces of metal under the seats, both of which are a strong point. Notably, some of the more reclining first-class seats have a three-point seatbelt, as it allows for more comfortable seats that do not facilitate a conventional brace position.)
In short, as a three-point harness adds proportionally less safety in an airplane as it does in a car, and a proportionally higher cost. The two-point seatbelt provides a very good protection even for fairly high impacts, despite the simplicity and very low weight (mostly of the two very strong mounting points of the seatbelt)
There are two main reasons:
1. Limited added safety from more complex belt, due to different nature of crashes. A typical airplane crash rarely comes as a full surprise. Rather, in most cases there is even time to teach and train the proper brace position (for example, prior to a suspected-to-be bad landing due to faulty landing gear or during the time between all engines failing and the inevitable hard landing to land or water). When implemented correctly, the brace position already suppresses the impact forces faced by the head and the torso, as one leans forward prior to impact rather than letting the head hit the seat ahead at speed (which we know to work based on past crashes, where the two-point seatbelt combined with a brace has been very effective at reducing both fatalities and injuries). A typical car crash comes comparably out of blue, leaving too little time to similarly brace for impact. Additionally, in a car that is crashing, there is much less space in front of you to be had before hitting something very hard*, like the steering wheel or in modern days the airbags (the airbags are very hard to hit, they are not soft cushioned bags of air but rather very taut and nearly solid bags of air; they provide, however, a less angular surface to collide than, say, steering wheel or the B-pilar).
2. It would increase the cost a lot, both initially and during use. A three-point seatbelt would need a third sturdy mounting point up top of the cabin, which would need a major redesign of all airplane interiors, and would also likely add plenty of extra weight per seat, increasing the fuel usage per flight. (*The backrests of regular airplane seats are not sufficiently strong for this purpose, as they are designed to flex upon impact to soften the impact forces of the person behind you, and also impact tested for this. And, neither is the bottom of the overhead compartments strong, not by a long shot. The impact forces taken by the seatbelts are massive, tens of times of your bodyweight. A two-point harness carries these loads conveniently to the floor of the aircraft via the fairly substantial pieces of metal under the seats, both of which are a strong point. Notably, some of the more reclining first-class seats have a three-point seatbelt, as it allows for more comfortable seats that do not facilitate a conventional brace position.)
In short, as a three-point harness adds proportionally less safety in an airplane as it does in a car, and a proportionally higher cost. The two-point seatbelt provides a very good protection even for fairly high impacts, despite the simplicity and very low weight (mostly of the two very strong mounting points of the seatbelt)
There are two main reasons:
1. Limited added safety from more complex belt, due to different nature of crashes. A typical airplane crash rarely comes as a full surprise. Rather, in most cases there is even time to teach and train the proper brace position (for example, prior to a suspected-to-be bad landing due to faulty landing gear or during the time between all engines failing and the inevitable hard landing to land or water). When implemented correctly, the brace position already suppresses the impact forces faced by the head and the torso, as one leans forward prior to impact rather than letting the head hit the seat ahead at speed (which we know to work based on past crashes, where the two-point seatbelt combined with a brace has been very effective at reducing both fatalities and injuries). A typical car crash comes comparably out of blue, leaving too little time to similarly brace for impact. Additionally, in a car that is crashing, there is much less space in front of you to be had before hitting something very hard*, like the steering wheel or in modern days the airbags (the airbags are very hard to hit, they are not soft cushioned bags of air but rather very taut and nearly solid bags of air; they provide, however, a less angular surface to collide than, say, steering wheel or the B-pilar).
2. It would increase the cost a lot, both initially and during use. A three-point seatbelt would need a third sturdy mounting point up top of the cabin, which would need a major redesign of all airplane interiors, and would also likely add plenty of extra weight per seat, increasing the fuel usage per flight. (*The backrests of regular airplane seats are not sufficiently strong for this purpose, as they are designed to flex upon impact to soften the impact forces of the person behind you, and also impact tested for this. And, neither is the bottom of the overhead compartments strong, not by a long shot. The impact forces taken by the seatbelts are massive, tens of times of your bodyweight. A two-point harness carries these loads conveniently to the floor of the aircraft via the fairly substantial pieces of metal under the seats, both of which are a strong point. Notably, some of the more reclining first-class seats have a three-point seatbelt, as it allows for more comfortable seats that do not facilitate a conventional brace position.)
People think plane crash is a jet crashing into the ground at 600 mph and exploding.
And yes, in that scenario, no seatbelt is going to help. It’s the deceleration that kills you, and going from 600mph to zero in no time at all is definitely going to do that.
However there are a lot of other more survivable types of plane crashes. Such as runway overruns. And these types of accident are much more common. They don’t involve as rapid a deceleration as a car accident, in the main, and there’s often warning that it’s going to happen – for example, an aircraft with hydraulic problems returning to the airport might overrun the runway due to poor braking performance.
Because there’s warning, you can go into the brace position, and brace against the seat in front. And if you don’t, the seat in front is designed to fold forwards as you hit it to minimise the damage.
Unless you’re in certain types of business class or first class seats, especially the angled types. These seats often have shoulder belts, like in a car, because there isn’t a proper brace position you can take.
It’s also worth pointing out that adding the structural weight to have a car-like seatbelt to every seat would be pretty significant, but not really help many people survive a crash, given how rare a plane crash is.
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