Collision damage to the 2001 Audi A6 is evident along the fender in front of the tire.

The car had traveled only about 200 feet from where it was parked before the crash occurred. Although the damage appeared to be minor and there were no injuries to any occupants, that collision ushered in a new era for Plano, TX, Fire Rescue responders and the fire service of this country. This case study is the first documented crash involving a 2001 model year Audi A6 where a roof-mounted side-impact airbag deployed.

By studying this incident, responders can better understand the components and operation of this unique airbag system. As you will see, the medical and vehicle rescue techniques we use today will have to be modified in order for our personnel to safely operate around these new airbag systems.

The side impact caused the roof-mounted airbag and the airbag within the driver’s seat to deploy.

The Real-World Crash

The brand-new, silver 2001 model year Audi A6 was pulling out of the driveway of the new-car dealership when it was struck in the driver’s front fender by another vehicle. The point of impact on the Audi was just ahead of the driver’s front tire. The collision spun the Audi completely around, facing it in the direction it had just come from.

The side collision caused the airbag in the driver’s seat and the airbag concealed in the roofline to deploy.

The Roof-Mounted Airbag

With both doors open, you can easily see the entire roof airbag in its deployed position. The front of the airbag curtain is attached to the front A-pillar by a small nylon strap. The rear of the airbag is attached to the rearmost D-pillar and an inflator cylinder.

The airbag deploys downward from the roofline to completely cover both front and rear door window. The creases in the deployed airbag indicate how tightly folded the airbag was while it was stowed above the roofline.

The Audi A6 airbag deploys down from the headliner, covering most of the side window areas.

The Seat-Mounted Airbag

Inspection of the interior shows that a second side impact airbag was concealed within the upright portion of the driver’s front seat. It is smaller in size than the roof airbag. The function of this seat-mounted airbag is to protect the front-seat occupant’s torso from injury.

Loaded Airbags

At this crash, only two airbags deployed. All emergency personnel must remain keenly aware of the fact that there are still two loaded airbags on the opposite side of this vehicle: passenger seat and passenger’s-side roofline. In addition, the driver and passenger frontal airbags are undeployed.

Remember, of the six airbags in this vehicle, only two deployed for this crash. Four others remain loaded.

The airbag deployed from the driver’s seat to protect the driver’s torso as the roof airbag deployed to protect the heads of the driver and rear-seat occupant.

Inflation Zone Considerations

EMS personnel should be very concerned when considering the inflation zone of roof-mounted airbags. In this Audi, both deployed airbags are about five inches thick at full inflation. The roof airbag has a large inflation zone, extending from the very front to the rearmost roof pillar, and from the roofline to the edge of the window opening as well.

To be the safest, any responder attending to a patient or any rescuer working with tools along the passenger side of this vehicle would have to remain outside of this huge inflation zone. In reality, that’s almost impossible and for real-world operations it’s just not practical. Take away the electrical power as soon as possible to begin draining the airbag capacitor.

Stored-Gas Deployment Systems

What is critically important for extrication crews to understand about roof-mounted airbag systems is that the entire roof airbag fills with a gas that, until the instant of impact, is stored under pressure in a small metal cylinder. On this Audi, the stored-gas cylinder is mounted directly to the inside of the rear roof pillar at window glass level.

Depending on manufacturer, these stored-gas cylinders may be pressurized with gases such as argon, helium or nitrogen to a pressure of between 1,400 and 3,000 psi.

The airbag deployed from the driver’s seat to protect the driver’s torso as the roof airbag deployed to protect the heads of the driver and rear-seat occupant.

Roof Extrication

Any extrication task that involves cutting the roof in some way on this Audi will involve working around the stored-gas airbag cylinders and the full-length roof airbags. The driver’s-side roof airbag is of no concern here because it deployed. The loaded passenger’s-side is, however, of great concern.

Instead of “flipping” or “flapping” a roof, crews should now consider total roof removal as the preferred assignment. This technique disturbs the complete roof airbag system the least. Remember to strip the trim off all roof pillars before you cut them. With the interior trim removed, you will be able to see items such as the stored gas cylinder. If you can see it, then you will be able to cut above or below it as you work to remove the roof.

Summary

By utilizing information from this real-world crash incident, you and your department members will be able to increase your familiarity with the design, components and operation of a roof-mounted side-impact airbag system.

This knowledge will now allow you to develop new operational plans for safe and efficient operations involving vehicles with roof-mounted side-impact airbag systems.