Parachutes in commercial aircraft.

[Moonbear]

Parachutes and ejection seats... uh, you guys know that these things take a five-point harness, right...? Can anyone say that they could strap-on a 5-point harness in a frisbee-ing plane? How 'bout a burning one? It's just unreasonable to think that it's possible.

Well, I'm sure I have sufficient skill to do that, but I can't be so sure about most passengers, and I expect the airline would get a lot of customer complaints if they even changed to a 3-point seatbelt system.

I think Grogs pretty much made the best argument against parachutes so far. I think people are just fantasizing about ejection seats now, knowing it's not at all realistic to do.

 

[FredGarvin]

This has to be the silliest conversation I have seen so far. Next time you're on a flight, take a look around at the winners around you. 95% of the people have a tough enough time with the seat belt and figuring out the bathroom doors let alone putting on a parachute (which I think very few people would be able to do when they needed to).

Ejection seats would probably kill more passengers than they would save. Especially the elderly. Then there are the "denisty/gravitationally challenged" that would require an extra boost on their seats. Although, I am sure Martin-Baker would love to outfit all of the world's airlners though. Let's fill a commercial airliner with 300 or so explosive rocket engines. Yeah. That's the ticket.

 

[Moonbear]

This has to be the silliest conversation I have seen so far. Next time you're on a flight, take a look around at the winners around you. 95% of the people have a tough enough time with the seat belt and figuring out the bathroom doors let alone putting on a parachute (which I think very few people would be able to do when they needed to).

I was thinking that they can't even get their bags up into an overhead bin without help. There are some seriously spatially-challenged people. On the last flight I was on, there was this guy standing in the aisle in the back of the plane trying to get against the flow of passengers getting onboard to find a space for his carry-on because he couldn't find space near his seat...I looked up at the bin right next to him and suggested if he just turned the other roll-away in it so it was turned the other direction, his bag would fit right next to it. He seemed to marvel at this revelation a moment before deciding to try it.

Then there are the "denisty/gravitationally challenged" that would require an extra boost on their seats.

I was trying to think of a nice way to say that. I don't think ejection seats come with seat-belt extenders. And what do you do about those people who have to use two seats?

The suggestion of ejection seats on a car is even funnier though. How fun to have them shoot you up into the air so close to the ground that there's no way to cushion your fall, and then you can land without the protective cage of your car smack in the middle of traffic. Sounds fun, huh?

 

[russ_watters]

The suggestion of ejection seats on a car is even funnier though. How fun to have them shoot you up into the air so close to the ground that there's no way to cushion your fall, and then you can land without the protective cage of your car smack in the middle of traffic. Sounds fun, huh?

Ejection seats on military aircraft are "0/0" - ie, they operate just fine at zero speed and zero altitude. They rocket you up to ~1,000 feet, so you're high enough for the parachute to deploy.

But again - before you can eject, you need to strap on your harness, lest you follow in the footsteps of that hapless boy who was the last person allowed in the cockpit of a military fighter jet at an air show...

 

[outsider]

:rofl: :rofl: :rofl:

This has to be the silliest conversation I have seen so far. Next time you're on a flight, take a look around at the winners around you. 95% of the people have a tough enough time with the seat belt and figuring out the bathroom doors let alone putting on a parachute (which I think very few people would be able to do when they needed to).

omg... I'm dying... LOL! :rofl: this is the ultimate answer!

Ejection seats would probably kill more passengers than they would save. Especially the elderly. Then there are the "denisty/gravitationally challenged" that would require an extra boost on their seats.

:rofl: Oh.. your killing me now... :rofl: Especially since more and more people want to fly, more and more people are "gravitationally challenged", and the boomers are only going to get older...

Come to think of it, the escape hatch in the back of the plane would cause a panic due to the fact that there are first class passengers sitting in the front who would "expect" to have the right to jump first. :tongue2:

Someone laterally challenged may have difficulty getting out of their seat and into their parachute given the cramped aisles... nevermind... i couldn't imagine everyone being able to get into their parachute all at the same time while in a panic without some human factors to cause a chain reaction...

FredGarvin, thanks for making my day!

 

[Moonbear]

Come to think of it, the escape hatch in the back of the plane would cause a panic due to the fact that there are first class passengers sitting in the front who would "expect" to have the right to jump first. :tongue2:

:rofl: I'm just enjoying the momentary thought of the look on those first class passengers' faces when they realize that person with the cheap ticket stuck sitting by the bathroom at the rear of the plane will be the first one to escape the doomed plane. :rofl: Ah, it would be such sweet revenge.

Ejection seats on military aircraft are "0/0" - ie, they operate just fine at zero speed and zero altitude. They rocket you up to ~1,000 feet, so you're high enough for the parachute to deploy.

Oh, goody! It'll be something new and exciting for the stupid teens to challenge each other to do. Why go to the amusement park when you can play with the seats in daddy's new beamer. Just watch out for the trees overhead. :tongue2:

 

[outsider]

:rofl: I'm just enjoying the momentary thought of the look on those first class passengers' faces when they realize that person with the cheap ticket stuck sitting by the bathroom at the rear of the plane will be the first one to escape the doomed plane. :rofl: Ah, it would be such sweet revenge.

bulkhead & "close to the front" seat requests will be replaced by seats nearest to the back of the plane... everyone will claim to have a bladder problem :tongue2:

Oh, goody! It'll be something new and exciting for the stupid teens to challenge each other to do. Why go to the amusement park when you can play with the seats in daddy's new beamer. Just watch out for the trees overhead. :tongue2:

oh.. that wouldn't happen *sarcasm* LOL

 

[EnumaElish]

Most commercial jet crashes occur on take-off or landing. You can't jump out of an airplane that close to the ground, and if you could, could you get 600 people to get strapped into parachutes and out one door in 5 seconds?

That's a fact. But suppose govt. regulations mandated numerous and wider emerg. exits and just like you can't board an airplane without a picture ID, suppose that you couldn't board without a basic training in para. jumping? I know this goes against the deregulatory spirit of our times, I am just hypothesizing here.

I also think bicycle helmets could be made mandatory for car passengers and they could end up saving lives.

P.S. Then again, after reading Grogs's post, I am not so sure about para. jumping's feasibility. But I still think helmets in cars would be a good idea.

 

[Moonbear]

I also think bicycle helmets could be made mandatory for car passengers and they could end up saving lives.

Not likely. At the speeds involved in car collisions, bicycle helmets are pretty useless.

Under US standards bike helmets are tested in 2 meter drops that achieve about 14 miles per hour (22.5 kph) on the flat anvil. In Europe the drop height is only 1.5 meters. Why so low, when bicyclists frequently exceed 14 mph in forward speed?

http://www.bhsi.org/limits.htm

Seat belts and airbags work much better by ensuring your head doesn't hit windshield or pavement.

 

[hitssquad]

I also think bicycle helmets could be made mandatory for car passengers and they could end up saving lives.

Helmets are intended not to save lives, but to reduce brain injury.

 

[hitssquad]

Not likely. At the speeds involved in car collisions, bicycle helmets are pretty useless.

Then how do people come away from car accidents with brain damage, or in comas, instead of dead?

 

[Moonbear]

Then how do people come away from car accidents with brain damage, or in comas, instead of dead?

Luck? If you still come away with brain damage, how has the helmet helped? That's what it's supposed to be preventing.

Helmets only protect at low speed collisions. Now, when a bicyclist is hit by a car, I would suppose the driver is usually slamming on the brakes and not hitting them at a full 50 or 60 mph.

Also, bicyclists are not hit by cars directly head-on. I found this and a lot of interesting information on this site:
http://www.helmets.org/henderso.htm

3.2 The kinematics of a bicycle collision

A careful field study of real-world cycle accidents was conducted in Germany (Otte, 1989). The predominant collision was between a cyclist and the front of a car. The subsequent kinematics were shown to be similar to car-to-pedestrian or motorcycle collisions. The primary impact is with the bicycle and the lower limbs of the cyclist. The body of the cyclist is then thrown up over the front of the car. Impact with the windscreen of the car is common at impact speeds as low as 25 km/h. In this study the mean collision speed was 36 km/h. The cyclist's head almost always hits the hood, the lower centre part of the windscreen or the A pillars that support the ends of the windscreen. The body of the cyclist is further injured by contact with roof structures, and at impact speeds of 55 km/h and over the cyclist is likely to be thrown completely over the car. This, of course, presents a renewed risk of head injury as the rider hits the ground.

However, I've also found contradictory information to the information cited by my first source regarding the reduction in injuries in Australia following implementation of the helmet laws, which instead suggests the reduction in injuries was actually due to a reduction in the numbers of people riding bicycles due to safety fears sparked by the initiation of helmet laws. One such site offering such evidence is this one:
http://www.magma.ca/~ocbc/hfaq.html#A4
(That site is pretty anti-helmet though, but it sure does provide an alternative view on things. Their reasons seem mostly that helmet laws deter people from riding bicycles, or for those who do wear them, gives them a false sense of security so they engage in riskier behavior.)

It also seems there are issues regarding which standards are used by various countries for certifying bicycle helmets. From the first source I provided, it seems Australia has changed their standards to address concerns with earlier helmet designs, but it seems more variable elsewhere. I'm not sure this site has the most recent information, but the Snell Memorial Foundation, which is a non-profit organization that certifies helmets claims the standards required in the US are lower than their own standards, so not all helmets are created the same.
http://www.smf.org/articles/bcomp.html

Again, this UK site concurs regarding the impact speeds for which bicycle helmets are tested:
http://www.whycycle.co.uk/safety-helmets.htm

What can a helmet do?

As with most safety orientated products, bicycle helmets have to pass certain standards prior to being allowed to be sold. What may be surprising is the exact nature of those standards.
Cycle helmets are only designed and tested to withstand an impact equivalent to an average weight rider traveling at a speed of 12 mph falling onto a stationary kerb shaped object from a height of 1 metre.
This is the equivalent of falling from your bike onto the road or the kerb edge.

Helmets are not tested nor expected to be able to offer full protection if you come into contact with a vehicle which is moving.

I have been entirely unable to find information regarding the actual speed of impact (even a good guesstimate) of a person's head with the car in collisions resulting in head injury and collisions in which the helmet prevented head injury, so I don't know how much of the effectiveness of bicycle helments preventing head injury are due to the rest of the body taking the initial force of impact and reducing the impact of the head with the car when the head finally collides.

According to Snell, there is a compromise/limit to improving the helmets further:

The other problem is, how much helmet will you wear. A good motorcycle helmet will generally provide more protection than just about any other helmet, but they are heavier and do not provide as much venting. This is OK for riding a motorcycle because in general you are not exerting as much physical energy as you would be on a non-motorized vehicle.

I also read in one of these sites, and now can't find it again (maybe it was one of the links I already closed) that if the helmets were designed to be more effective in higher speed impacts, they'd lose some effectiveness in lower speed collisions, such as a kid falling off his bicycle.

Anyway, all of this is probably pretty different from what would happen to the driver or passenger in a car who is in a crash at higher speeds and their head slams into the windshield at the full 55 mph they are traveling when the car comes to a sudden stop, or when they and the entire weight of the car crushes down on their head as the car rolls. Maybe a motorcycle helmet would help, but then it would probably limit posture with a seat back behind you that you wouldn't have on a motorcycle (the seat head rest is there to prevent neck injuries), might be restrictive of how well you can turn your head to look for obstructions, etc. Plus, cars aren't designed with all that much head room...I don't know if a tall person could fit in some cars with the added height of a helmet on their head.

I guess the bottom line is bicycle helmets are designed for the impacts that bicyclists are likely to experience, not the impacts motor vehicle drivers are likely to experience.

 

[hitssquad]

Car drivers wearing bicycle helmets to reduce injury potential

I also think bicycle helmets could be made mandatory for car passengers and they could end up saving lives.

Not likely. At the speeds involved in car collisions, bicycle helmets are pretty useless.

Then how do people come away from car accidents with brain damage, or in comas, instead of dead?

Luck? If you still come away with brain damage, how has the helmet helped?

We were talking about potentially helmeting car passengers. As far as I know, car passengers do not generally wear helmets. If that is indeed the case, asking 'how has the helmet helped' is an instance of the complex question fallacy.
datanation.com/fallacies/distract/cq.htm

 

[Moonbear]

We were talking about potentially helmeting car passengers. As far as I know, car passengers do not generally wear helmets. If that is indeed the case, asking 'how has the helmet helped' is an instance of the complex question fallacy.
datanation.com/fallacies/distract/cq.htm

Oh, I misunderstood. I thought you were talking about bicycle helmets on bicyclists colliding with cars since, as you point out, car passengers don't wear helmets. Oh well, I learned a lot more than I ever would have otherwise about bicycle helmets in the process.

 

[Ivan Seeking]

Here's the newest high speed impact resistant helmet.

http://66.132.232.61/prodimages/R13014.gif

 

[Moonbear]

Here's the newest high speed impact resistant helmet.

http://66.132.232.61/prodimages/R13014.gif

[/URL]
:rofl: Uh oh, I caught you. Obviously you didn't read all those links I provided, or you'd know that most collisions of bicyclists' heads with hard surfaces happens at the front of the head not the top of the head; some lethal injuries in helmet-wearing riders occur when the impact is just below the front of the helmet. (Well, darnit, after I read through all that information on bicycle helmets trying to answer hitssquad's question only to find that's not the question he asked, I'm going to use that information for something! :grumpy:)

 

[hitssquad]

You might find the phrase "risk compensation" interesting and useful, though, Moonbear. It implies that if car drivers wore helmets, they would drive more-recklessly. More-reckless driving implies that more bicyclists would be killed. EnumaElish said, "I also think bicycle helmets could be made mandatory for car passengers and they could end up saving lives." But maybe that would not be the case.

 

[Moonbear]

You might find the phrase "risk compensation" interesting and useful, though, Moonbear. It implies that if car drivers wore helmets, they would drive more-recklessly. More-reckless driving implies that more bicyclists would be killed. EnumaElish said, "I also think bicycle helmets could be made mandatory for car passengers and they could end up saving lives." But maybe that would not be the case.

That's also addressed in one of my links above...the one that's anti-helmet laws. Well, it's addressed in the context of bicyclists taking more risks if they wear helmets, not drivers taking more risks, obviously. I would think wearing a helmet in a car is redundant if one wears a seatbelt. It's the unrestrained driver/passenger who goes through the windshield head first. I don't know what other sorts of auto accidents result in severe head injuries, but they probably would be quite different in terms of how the impact occurs than what a bicycle helmet is designed to protect against. The helmet wouldn't do anything for the risk of smacking your face into the steering wheel, but then that's why airbags are also installed.

Locally, we seem to have had an abundance of car accidents recently where drivers were unrestrained in one of the vehicles. It really makes the message clear of just how much seat belts help when the unrestrained driver is ejected from the vehicle and pronounced dead on the scene or dies soon after arrival at the hospital and the restrained driver walks away uninjured except for a bruise on their shoulder from the seatbelt.

 

[hitssquad]

Automobile head injuries and side-curtain air bags

I would think wearing a helmet in a car is redundant if one wears a seatbelt.

Persons who wear seatbelts sustain head injuries, Moonbear. That is why people spend extra money on cars that have side-curtain airbags.
http://www.hwysafety.org/vehicle%5Fratings/ce/html/side/s0411.htm

In the first test, the driver side curtain airbag deployed improperly, with the result that the driver dummy's head was hit by the impacting barrier. Subaru found that the side curtain airbag manufacturing facility had been assembling the airbags incorrectly. This led Subaru to correct the assembly process for the side curtain airbags on models produced after June 1, 2004. Also, Subaru initiated a safety recall to modify, at its cost, vehicles produced earlier. The Institute tested a second Legacy with the modified airbags, and the driver side curtain airbag inflated properly, preventing the driver dummy's head from being hit by the impacting barrier.

 

[Moonbear]

Persons who wear seatbelts sustain head injuries, Moonbear. That is why people spend extra money on cars that have side-curtain airbags.
http://www.hwysafety.org/vehicle%5Fratings/ce/html/side/s0411.htm

So that's a side-impact. Since (I think) we're still talking about bicycle helmets, those aren't tested for effectiveness against side-impact (and they don't really cover much of the side of one's head anyway), so we can't really determine if a bicycle helmet is going to help with that sort of head injury. Since most of the side of the head is not covered by a bicycle helmet, I'd lean toward thinking it's not going to help.

 

[hitssquad]

Bicycle helmets go down on the sides to right above the ears, Moonbear.

http://www.lori-and-al.com/blogs/about_town/images/0818_meinhelmet.jpg

See how the dummy's head is tilted so that the top-left of his head smudged the curtain?

http://www.hwysafety.org/vehicle%5Fratings/ce/html/side/photos/s0411_3_grab.jpg http://www.hwysafety.org/vehicle%5Fratings/ce/html/side/photos/s0411_4_24.jpg

Even if some of the rest of his head hit in this test, a bicycle helmet might help keep those parts from impacting.

 

[Moonbear]

Bicycle helmets go down on the sides to right above the ears, Moonbear.
...
Even if some of the rest of his head hit in this test, a bicycle helmet might help keep those parts from impacting.

Okay, somehow I was thinking of bicycle helmets fitting differently (I don't bike, so have never worn one, and was thinking they were more open on the sides). So, they do cover the relevant places, but since what you're images are showing are side-impact tests with side airbags, I'll refer back to my initial point.

Seat belts and airbags work much better by ensuring your head doesn't hit windshield or pavement.

Granted, I was only thinking of forward motion and front airbags at the time, but I think you've provided sufficient reason to also consider side-impact and side airbags.

There must be data available about the speeds or force of impact at which side-impact airbags are effective and when the force of impact would exceed that at which the airbags are effective in preventing head injuries. Only with that information could we make some determination of whether a helmet or an airbag might provide better protection. (I know, the burden of proof to find that is on my side now; I do need to do some actual work today though, so won't be looking for it any time soon...if you have any of that information readily available, I would appreciate it if you'd share it).

(:uhh: I hope nobody was still interested in discussing whatever the topic was that we started out with...oh, right parachutes in planes...we've strayed quite away from that.)

 

[hitssquad]

There must be data available about the speeds or force of impact at which side-impact airbags are effective and when the force of impact would exceed that at which the airbags are effective in preventing head injuries. Only with that information could we make some determination of whether a helmet or an airbag might provide better protection.

The cost of each option does not matter?

 

[Moonbear]

The cost of each option does not matter?

That would depend on how similar the effectiveness is. If one is going to provide little to no protection and the other substantial protection under the conditions of typical car crashes, then cost (monetary) would be weighted less based on effectiveness. But, if both provide similar protection, or at least some reasonable degree of protection under typical crash conditions, then weighting cost vs benefit becomes more of an issue.

Of course, if we do end up factoring in cost, then we also need to consider what other injuries are prevented. We've been focusing on head injuries, and that's all that a helmet will prevent. Airbags and seatbelts prevent additional serious injuries to the upper body that are not prevented by a helmet.

I'm also not certain if the original suggestion of wearing a helmet was intended to mean instead of or in addition to seatbelts and airbags. I can't tell from the first reply that mentions it. If it's in addition to, then we'd have to show that a helmet combined with other safety equipment provides sufficiently more protection than not wearing the helmet to justify all of the costs (including enforcement). If it's instead of, then we have to take into consideration all of the possible injuries, not just head injuries.

 

[hitssquad]

Right now, side curtains are usually optional/not-available:
http://www.hwysafety.org/vehicle%5Fratings/side%5Fairbag%5F01%5F02.htm

There is an opportunity for the car consumer to decide between helmet and curtain.

 

[Jimmy Snyder]

Perhaps people are not as cynical as they were when I was a kid. Then the standard answer was that the airlines preferred to pay off the relatives of the dead than provide lifetime care for the injured.