Airbag Safety: Introduction
Airbag safety is an important issue these days because a reasonably modern car commonly has four to six explosive airbags on board. Cars have become much safer, but there are airbag safety issues to consider. It’s easy to these so-called 'passive safety' devices (passive: because all they do is wait for a crash) to adapt to the related airbag safety issues.
Airbag Safety: Where are They?
Front airbags– emerge from the centre of the steering wheel, and the larger passenger’s airbag shoots out of the dashboard above the glovebox, through a concealed aperture.
Side airbags– deploy from the outboard edges of the front seats to protect the head and thorax in side impacts.
Curtain airbags – erupt downwards, out of the headlining in the roof, during side impacts. Curtain airbags also help keep the occupants restrained during a rollover, and protect rear-seat occupants.
Seatbelt pre-tensioners – explosively pull the seatbelt tight, removing slack and ensuring the occupants are tugged into the right position to benefit from the airbag’s protection.
Airbag Safety: How Many Do I Need?
The more airbags, the safer. Cars with a five-star ANCAP safety rating (www.ANCAP.com.au) generally offer superior side-impact protection than lower-rated cars. These always have six airgags (two each of: front airbags, side airbags and curtain airbags). Double-income with no kids? Front bags and head-protecting side airbags are the minimum you'd need, but if you add curtain airbags, that's ideal. Kids and those in the rear are only protected by curtain airbags, which extend the length of the cabin.
Airbag Safety: How They Work
Pat Clarke, a technical trainer at Hyundai and a member of the Society of Automotive Engineers, says when crash sensors in a modern car feel the massive deceleration of a crash, they fire the airbags. A gas generator, usually fuelled with solid propellant, fills the nylon airbag with nitrogen gas. It inflates in around 0.03 seconds – 10 times faster than the blink of an eye. The bag reaches speeds greater than 200km/h – just to get into place before you hit it. The bag is stationary, inflated and waiting, by the time you get to it. “The airbag inflating isn’t what protects you,” Clarke says. “What does the protection is you hitting the static airbag and pushing the nitrogen gas out of it, via vents, like a cushion.”
Airbags are lubricated by white powder – typically French chalk or talcum powder – which explains the light frosting on everything after a serious crash.
Airbag Safety: The Dashboard is Not a Shelf
Graham McGrath, a senior MICA Paramedic in Victoria, has some simple airbag safety advice: don’t put anything on the dash that you wouldn’t want to hit you in the face at 200km/h. “Airbags can launch projectiles towards you at high speed,” he says. "So I’d find somewhere other than the dash for the street directory and even your sunnies – which have pretty sharp edges.” McGrath also says dash- and pillar-mounted notepads favoured by couriers and reps have “real projectile potential” and not something to fit if you're concerned about airbag safety.
Airbag Safety: Will they Hurt Me?
The major airbag safety no-nos: driving with your arms diagonally across the steering wheel, and passengers with their feet up on the dash. Clarke: “Being in the wrong position spoils the deployment of the airbag, and it can hurt you – if you’re twisted sideways, the pre-tensioner could break your collarbone. If you're out of position, an airbag could break your arm, or your ankles if your feet are up on the dash. Worse, because you’ve spoiled its deployment, then it can’t protect you properly. Seat covers and dash mats that aren’t designed for airbags can ruin the deployment, too.” Airbag safety involves serious consideration if you are a driver or a passenger. For the best airbag safety result in a crash, you need to be in the right position so that the full safety of the airbag can be realized.
Graham McGrath says people who sit properly in cars sometimes suffer – at most – superficial bruising or grazes as a result of airbag interaction. Of course, the crash itself could still cause significant injury. “Airbags can fracture limbs if they get in the way, so it pays to sit in the car with due respect.” McGrath also says broken fingers are common if the driver rests these on the steering wheel’s airbag module. “We’ve had a fractured right shoulder dislocation, from a guy driving with his elbow up on the sill when the side airbag deployed. I guess that kind of thing will become more common as more cars are fitted with side airbags, but still I’d much rather have side airbag protection than not.”
Airbag Safety: Kids’ Stuff
New car safety laws in NSW and other states effectively ban children under seven from riding in the front seat – mainly because airbags are precisely choreographed to protect adults. Some cars have a key-operated ‘off’ switch for the front passenger’s airbag. These allow the safe fitting of rear-facing baby capsules in that seat overseas … but in Australia babies aren’t allowed in the front. It’s also illegal to deactivate the front passenger airbag in Australia. The best airbag safety advice for children? Ensure they ride in the rear seat.
Airbag Safety: Don’t Touch the Yellow Wire!
Planning any DIY auto-electrics? This is now a serious airbag safety consideration. Pat Clarke says it is possible for the unwitting DIY auto electrician to deploy an airbag accidentally – with potentially fatal consequences. But take heart, it's possible to deal with airbag electrical wiring safely: if you intend to wire-in a new sound system this weekend; there’s a simple airbag safety solution. “By law, all the automotive wiring that’s connected directly to airbags is bright yellow,” says Clarke. “So, there’s a good airbag safety tip: don’t touch the yellow wire.”
Airbag Safety: Rescue Me
So, do they work? Clarke: “The choice is fairly simple: which would you rather do – hit the airbag with your head, or the windscreen?” Rescuers agree. Clayton Alison from Hurstville Fire Brigade in Sydney has spent more than a decade as a crash rescuer. Judged best rescue team leader at the 2009 Australasian Rescue Challenge, he says unexploded devices in crashed cars deserve respect, and they make his job “more difficult and technical”. But he’s unequivocal that this is a good thing: “I’m arriving at jobs these days that look quite horrendous. Fifteen years ago, with the same damage I’d be thinking: ‘this patient is going to be pretty messed up, and require a lot of our support’. Same crash today; we roll up, and when we find our ‘patient’ they’re often signing the tow truck driver’s paperwork. The difference is massive today.” Aibags in cars have made a massive improvement to safety.
Read our post on safe child restraint in cars.