Roof Airbag Stored Gas Inflators

April 1, 2008
SUBJECT: Airbags

TOPIC: Roof Airbag Stored Gas Inflators

OBJECTIVE: Given a late-model vehicle at a crash scene equipped with undeployed roof airbags, the rescuer will be able to locate the stored gas inflator units.

TASK: The rescue team shall study the various designs of roof airbag systems and be able to list the possible locations for a stored gas inflator unit to be mounted on the vehicle.

It seems that rescuers across this country are getting the word on the fact that many airbags found in late-model vehicles deploy not because of a chemical reaction, as was once the standard, but because a pressurized cylinder vents its contents of argon and helium gas into the airbag. Coined with the phrase "stored gas inflator," these cylindrical metal units are now used by all manufacturers to deploy their roof airbags when a collision occurs. Stored gas inflators can also be used to deploy seat-mounted airbags, door-mounted airbags, knee bags and even the passenger front airbag on some vehicles. The only airbag location across all manufacturers that operates with the original style chemical inflator is the driver's frontal airbag.

So, as we become more knowledgeable about stored gas inflators for roof airbags, it seems that the phrase "strip the trim" has also become a popular teaching point. The action of peeling away the interior headliner or roof pillar trim of a crashed vehicle at your intended roof cut points is now generally accepted as a "must do" prior to cutting away any portion of a vehicle's roof.

Well, it also seems to this author that there may be a misconception among rescuers about stored gas inflator locations. Most rescuers will tell you that if they confront a vehicle equipped with roof airbags and the roof has to be cut off, the stored gas inflators will be found on the rearmost roof pillars; the C- or D-posts. Although this is the most common place for a stored gas inflator to be found, it isn't the only location.

The vehicle featured in this University of Extrication article is a great case in point. It is a crash-damaged 2007 Toyota Camry. The four-door sedan is equipped with dual frontal airbags, a driver's knee bag, front-seat side-impact airbags and full-length roof airbags. There are a total of seven airbags in this vehicle. The images and captions presented walk you through the process of determining the exact location of the pressurized stored gas inflators for the roof airbags. They aren't always where you think they might be, as you will see.

This is actually a good location for the stored gas inflator as far as vehicle rescue is concerned. With a roof rail location for the stored gas inflator, do a total roof removal. Cut the A- and C-pillars on both sides, cut the windshield across at the defroster level, cut all seatbelts and lift the roof off the trapped patients. Even if you cut into the undeployed airbag itself, that's OK. Just don't cut into the metal cylinders that are on the roof rails. They're the 4,000-psi "monsters" that can be a real hazard to you, your personnel and your patient.

TASK: The rescue team shall study the various designs of roof airbag systems and be able to list the possible locations for a stored gas inflator unit to be mounted on the vehicle.

Where do you go next?

Because the roof airbags are undeployed, you go to strip the trim. You start by prying off the interior panel on the passenger-side rear C-post. What is revealed underneath the rear trim is a portion of the roof airbag but not the stored gas inflator.

Now where do you go?

Since it looks like the end of the roof airbag is at the C-post, then maybe the other end and the stored gas inflator is mounted to the A-post. You strip away that trim panel and still no inflator; just the other end of the folded airbag.

Now, once the inflator is exposed, where do you make your roof cuts?

The third location where you will typically find the roof airbag stored gas inflator is at the center of the roof rail, above the B-post. In this case, with this particular make and model Toyota, that is in fact where the stored gas inflator is mounted.

RON MOORE, a Firehouse® contributing editor, is a battalion chief and the training officer for the McKinney, TX, Fire Department. He also authors a monthly online article in the "MembersZone" and serves as the Forum Moderator for the extrication section of the website. Moore can be contacted directly at [email protected].

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