The airbag is the passive safety system that saves most lives behind the safety belt. In fact, its effectiveness is only possible when combined with that device. This is so much so that the airbag control system (the one that causes the bag to unfold at the exact moment) is designed according to all the dynamics associated with the belt. When a collision occurs, the exact point at which the body is retained by said system is taken into account, and the airbag deploys at the precise moment in which it maximizes its function. But at what speed do the airbags jump ? Can they jump by mistake?
The design of the airbags takes into account, above all, the deceleration suffered in a collision. It is surely the most important data to decide the deployment, or not, of the airbag. That is, an airbag does not jump when the car is damaged, and it does not do so depending on the speed at which the vehicle circulates, but it deploys when the deceleration is important enough. At that moment, the airbag sensor sends a signal to the control system and the bag is deployed, saving the life of the occupants.
The NHTSA, for example, figures that deceleration as the equivalent of hitting a solid wall at about 27 or 28 km / h. That collision is, speaking very roughly, equivalent to hitting twice the speed against the front of a car of the same dimensions that is parked. This is because, unlike a solid wall, the parked car will absorb energy from the impact, in addition to being displaced by the blow.
On the other hand, real accidents and collisions do not happen at perfect angles as happens in crash tests, but they are practically random, and the forces of impact are evenly distributed across the front of the vehicle. In this way, the relative speed between the vehicles involved that is required for the airbag system to be activated may be greater than that required in a crash test , hence the key datum for deployment is deceleration, and not the speeds involved. .
How fast is the airbag? Can it be deployed by mistake?
It seems the same question, but in reality it is not. Perhaps you thought, in the first instance, about the speed at which the airbag is deployed when a collision occurs. Well, the speed at which the car’s airbag comes out is enormous, it is estimated that it exceeds 250 km / h.
The complete process of inflation of the bag (which is not filled with air, but nitrogen) lasts only a few hundredths of a second, and here are some extra data : a frontal airbag is triggered after approximately 30 thousandths of a second. the impact occurs, about 50-60 thousandths of a second later, the driver’s head already hits his airbag; the occupant does it about 10 thousandths of a second later.
It is very difficult to be aware of the fact that an airbag is deployed by mistake. There have been cases, but they are very, very rare. The airbag could be deployed, yes, without a frontal impact collision to use, for example if there is a strong enough impact on the underside of the car, because there is something on the road and we do not realize. However, over the years, control systems and sensors have been refined so that fewer false positives are given each time.
Can the airbag be skipped without the safety belt fastened?
The airbag jumps in the event of a collision and when the deceleration parameters cross a certain threshold, whether or not the safety belt is fastened . But, as we said at the beginning of the article, an airbag without the collaboration of the safety belt does not act efficiently. Moreover, it can cause injuries to people because they will be placed in the wrong place when the bag reaches the maximum volume.
Always wear the seat belt correctly fastened, so that any of the available airbags contribute to minimize the consequences of collisions with full warranty.