The deployed BMW Head Protection System (HPS) airbag is attached to the base of the A-pillar and along the roof rail by black nylon tether straps. The bag is filled with argon and helium gas delivered from the stored gas inflator module mounted to the inside of the A-pillar.

For all responders who have worked and practiced the technique of “rolling” a dash off a trapped driver, there is something new and very important for you to be aware of. For those who are trained in “jacking” the dash, you too should study this information before you make your next cuts in an A-pillar. Even crews who may have to pry a door off a car must take note of the following “discovery.”

The New Technology

The BMW side-impact airbag system, available since the 1998 model year, has added a very important new twist to dash and jammed door rescue evolutions. BMW’s side-impact airbag system consists of two airbags; a door airbag and an inflatable tubular Head Protection System (HPS) airbag mounted along the roofline.

With the interior panel of the door, removed, the side-impact airbag mounted to the door is visible. The stored gas inflator module is contained within this metal airbag box bolted to the door.

The BMW door and the roof airbag do not use a chemical reaction to deploy the airbags; they utilize high-pressure stored-gas cylinders inside the car. The stored gas, held inside a small metal cylinder until impact, flows out of the inflator module, through a plastic tube and into the airbag, deploying the airbag instantly.

The door airbag inflator module is secured inside the door airbag unit itself. It is somewhat protected by the door collision beam.

The stored-gas inflator for the BMW roof airbag is mounted to the inside of the A-pillar, level with the top door hinge. The bolts of the top door hinge actually point toward this inflator module. The cylinder is mounted underneath the instrument panel and is not readily visible. The concern for responders is obvious. We now can have a pressurized cylinder within our rescue tool prying or cutting zone.

A replacement HPS airbag is being installed in this BMW. The stored gas inflator module is visible along the inside of the A-pillar near the top door hinge. The airbag fill tubing runs along the A-pillar. The bag is secured above the headliner.

If the tubular HPS airbag has deployed from the roof or the door-mounted airbag has deployed through the door panel, that particular stored-gas cylinder is empty and is of little concern to rescue personnel. If the BMW roof or door airbag is still “loaded,” however, the inflator modules are still pressurized.

Effect On Vehicle Rescue Tasks

There are several considerations for modifying our standard rescue evolutions when encountering a BMW with a loaded door or roof airbag.

When removing a door by forcing it off at the hinges, be alert to any inward crushing of the A-pillar when you are prying at or near the top door hinge. Movement of the A-pillar may cause unwanted contact with the pressurized gas cylinder. Consider a power cutter or reciprocating saw to cut through the actual hinge itself as a safer alternative technique.

The high-pressure stored gas cylinder for the BMW roof airbag system is visible inside the A-pillar. Under normal conditions, it is hidden under the plastic of the instrument panel. Note how this location puts it well within our rescue work zone.

Remain aware of the position, location and inflation zone of door and the roof airbag inflator modules if there are loaded airbags within your work zone.

When moving the dash, instrument panel and firewall off a trapped front-seat occupant, the pressurized roof airbag cylinder is again right within your work area. To roll the dash, the A-pillar relief cut or cuts are generally low, usually near the bottom door hinge or into the rocker channel. Remain aware of any cutting near the top door hinge.

Relief cuts are also made in the A-pillar when jacking the dash. With a loaded roof airbag, make these two cuts between the door hinges about two inches apart. Make your first cut at the top of the bottom hinge and the second cut just a few inches above the initial cut. These locations will allow you to avoid any A-pillar cuts up near the top door hinge.

Our hydraulic cutters are powerful enough to not only cut the A-pillar, but could at the same time puncture the pressurized airbag inflator module. This will result in a catastrophic failure of the cylinder with potentially fatal results to anyone in the hot zone.