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This is a single stage driver’s
frontal airbag. Notice the single plug in the center of the back.
These were the first airbags installed in vehicles and were used by some manufacturers through
the 2006 model year. Though they operate the same, very few look alike, each one is shaped to fit a particular steering wheel
design.
The inflation zone for these is 10 inches from
the center of the steering wheel to any part of the driver's body.
Rescuers should never put themselves or any type of equipment
between this airbag and the victim.
Since the early 1970s rescuers have been taught that if the
airbag is deployed, there is no more danger, it can not deploy a second time.
Warning! This is no longer
true!
This is a driver's dual stage frontal airbag. Notice
the two plugs in the center of the back.
These have two individual inflator units that can be deployed
individually or both at the same time.
Though these have been used for several years, federal standards
require them in every vehicle from 2007-up.
Warning!
Rescuers must never enter the 10 inch inflation
zone of any driver's frontal airbag.
From the front side, which is what the rescuer
would be looking at, many of these look identical.
When installed in the vehicle it is impossible
to tell which one is single stage or which is a dual stage.
Being bolted to the steering wheel, rescuers could
never see this view.
With each inflator unit being able to deploy individually,
many times one side will still be loaded, even though you see the bag hanging down.
Warning! It is impossible to visually tell
if both sides have deployed or not.
Even looking at the back side, it is impossible
to tell which side is deployed.
This airbag was deployed under controlled conditions for a
classroom display. One side is still loaded, but even looking at the plugs, it is impossible to tell which side deployed.
Warning!
Today we must treat every frontal air bag
as if it was a non-deployed
one.
Never put yourself or any piece
of equipment
between the air bag and your victim.
Smart Airbags
Smart airbags, is simply a name given dual
stage airbag systems; because by the uses of sensors and controls they can regulate their own deployment.
One of the sensors used with the driver's frontal
airbag is the seat position sensor. There are many different types of these sensors but they all do the same thing. They measure
the distance between the seat and the airbag deployment zone, or front of the steering wheel.
This allows the control module to deploy the
airbag according to the occupant's proximity to the inflation zone.
These sensors are mounted in the seat adjustment
tracks.
Most of these sensors operate in four zones. Zone
#1 being the closest to the steering wheel and zone #4 being the furthest away.
Depending on the zone the seat is in at the time of the crash,
the control module can; not deploy the airbag, deploy only one side, or deploy both sides.
As rescuers; we have always been taught that if
a vehicle is equipped with electrically operated seats, to move the seat as far back as possible before disconnecting the
battery.
Because of the operation of these sensors, many extrication
instructors disagree on this procedure and both sides can be right in their teaching. (Details in the in depth studies).
As a general rule of thumb; Consider the size of the
occupant, if you have sufficient room to perform your rescue without compromising the Vitim's spinal alignment, simply adjust
the back rest portion of the seat, to assure they are out of the inflation zone. If not then move the seat, but be sure that
it is moved as far as possible; because this action will change the path of deployment in the control module, setting the
airbag up for a second deployment should an accidental charge of electricity enter the system.
Frequent Ask Questions
Many questions arise about
why these airbags deploy in some crashes and not in others. Being a frontal impact airbag, these will only deploy in a front
end type collision. The vehicle must be impacted either straight on or within a 30 degree angle from either side of the center
line of the vehicle.
Also these systems depend on crash sensors that must experience a certain amount of deceleration, or sudden slowing of the vehicle.
Many times a vehicle that sets higher than the one it hits, will impact above the crash sensors and the thinner metal
of the hood and fenders will absorb the impact, not allowing the crash sensor to experience enough deceleration. (This is
covered in the in depth studies)
Another question is about the use of steering wheel covers:
This one gives us a very good example of how we develop our
training and why we so desperately need a change in our training. Take a look at conversations we find on major fire/rescue forum
boards.
The forum below is a very good example of
the desperate need for training and the lack of funding for it.
Does anyone use airbag
/ steering wheel covers during extrication? I am not sure what companys make this product with the exception of Halmatro.
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Capt, I have toyed
with this subject matter recently, and did some experiementing during training. Being that few departments have the actual
tested products, including ours, I did some field testing with some homemade devices. We took seatbelts out of vehicles and
made a simple device by weaving them together to make a 4 point connection which diverted the force, we used the simple rescue
rope technique, but, the one we found that worked the best was an idea that I came up with while working out in the gym. I
saw the weightlifting belts and how the design of it could be used, with the portion that protects the lower back being larger
and oval. I took one out to the training ground and the connection was simple and extremely strong. The leather belt had a
good coverage and the buckle had 4 reinforced points of contact. None of these procedures are sanctioned
by any formal organization, but I figured something was better than nothing........I think we will find the
approved products working their way into our cache of equpment as a necessity with the increasing technological aspects of
todays vehicle market.....Thanks
Thats a great idea
and a heck of alot cheaper than purchasing the airbag covers. Specially if
you are on a tight budget.. Way to go in adapting and overcoming in the efforts to protect yourself and fellow brothers and
sisters.. I will take this idea back to my department and try it out. Thanks for the input..
And hey ya know if you find a way to modify the design of that back brace and still be effective you could always market it...
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There is equipment
on the market to protect us from the driver’s frontal air bags. Some departments have them and SOPs or SOGs in
place for using them, but let’s take a look at what they do.
First they are only protecting us from one of the 37 danger that you
will see in the in
depth
studies.
Secondly,
they can factor in human error by not being applied properly. In the in depth study, you will find that the
second part of our tactic of working With the system, protects us from this human error. Rushing to an MVA at 3:00 am, have you ever made a mistake? Let’s
say we did make a mistake, now we have a projectile traveling at 2-3 hundred mph directly into an already injured victims’
face. Now we have a real problem, this projectile just took the liability off of the manufacture and put it on you and your
department, because it was not properly installed.
Thirdly, we can build
a false sense of security allowing us to put our self in the inflation zone
Finally, when these covers
were being developed in the late ’80s and early ‘90s, we were faced with one single stage airbag per vehicle,
and steering wheels with a steel ring inside them. Today we may be faced with as many as twelve airbags per vehicle and new
steering wheel construction that may not be able to hold some types of these covers
Many steering
wheels no longer have a steel ring inside them. Most of the newer models have an aluminum tube as shown Above. These
tubes are actually made to bend, in order to lessen chest injuries in a sever crash. The force of an airbag deployment against
the cover can easily bend one, as seen here releasing the cover as a
projectile. With the dual stage airbags of today we have the risk of a second deployment, doubling the chance of this happening.
View Life Net In Action
click here to play video
The goal of TRW’s self adapting vent system is
to lessen the deployment force of the airbag if the driver is close to the airbag enclosure. In this out of position scenario,
the airbag deploys more immediately into the occupant and a vent at the rear of the airbag module opens. This allows the force of the airbag to dissipate rapidly, especially for unbelted occupants.
When an occupant is in a normal position, the self adapting vents in the airbag module
remain closed and allow the airbag to inflate at normal pressure. The system can also be used in concert with dual stage or
lower output inflators that can further tailor the deployment to occupant position and passenger size
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Figure
1
The occupant is out of position when an accident occurs. TRW’s adaptive venting system compensates by opening
the vents. This allows some air to escape lowering the airbag’s pressure |
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Figure
2
When the occupant is in a proper position, the vents are closed and the airbag deploys at full strength |
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