No Air Bag Deployment

[Carlacee]

I saw this 2006 RAM CTD 3500 Q/C at the shop where I have my truck worked on. I checked the cab area and to my amazement there was no air bag deployment!!



Has anyone else seen anything like this??



My gawd, it should have deployed!!

 

[Grizzly]

That's kind of scary that it didn't deploy. Is there any way air bags can be tested to make sure they will deploy if the need should arise?

 

[kenny61]

I'm looking at the pic on a small screen so its hard to tell...



Air bags will only depoly under certain circumstances and require the proper amount of decelration on a certain axis. They do not deploy just because a bumper is pushed in or from side impacts. I've seen a lot of crashes and the bags only deploy in a small percentage of them especially with the newer cars. I think the older ones were designed by the amount of bumper deflection but the technology has progressed and there is a whole bunch of criteria that must be met before they deploy

 

[rscurtis]

There is always the possibility that this truck saw a previous deployment and that it was never replaced.

 

[Grizzly]

I'm looking at the pic on a small screen so its hard to tell...



Air bags will only depoly under certain circumstances and require the proper amount of decelration on a certain axis. They do not deploy just because a bumper is pushed in or from side impacts. I've seen a lot of crashes and the bags only deploy in a small percentage of them especially with the newer cars. I think the older ones were designed by the amount of bumper deflection but the technology has progressed and there is a whole bunch of criteria that must be met before they deploy

With that much damage, it should have deployed. I know it needs to trigger certain sensors for the bag to off. Guess the 06 truck didn't have side air bags.



I ordered my truck and both cars with side air bags.

 

[BHiggins]

I've heard stories of guys disabling their air-bags for snow plowing (I don't SEE a plow frame on that truck, but you never know).

 

[kenny61]

I see what appears to be a lot of scrape damage to the drivers side hood door and roof looks like it rolled over and slid form the picture I can tell if the front sustained a direct impact or if its just from the bumper being pushed and squeezed from a roll over maybe Carlacee can tell us a little more.

 

[kenny61]

From Wiki

How airbags work


The design is conceptually simple; a central "Airbag control unit"[25] (ACU) (a specific type of ECU) monitors a number of related sensors within the vehicle, including accelerometers, impact sensors, side (door) pressure sensors,[26] wheel speed sensors, gyroscopes, brake pressure sensors, and seat occupancy sensors. When the requisite 'threshold' has been reached or exceeded, the airbag control unit will trigger the ignition of a gas generator propellant to rapidly inflate a nylon fabric bag. As the vehicle occupant collides with and squeezes the bag, the gas escapes in a controlled manner through small vent holes. The airbag's volume and the size of the vents in the bag are tailored to each vehicle type, to spread out the deceleration of (and thus force experienced by) the occupant over time and over the occupant's body, compared to a seat belt alone.

The signals from the various sensors are fed into the Airbag control unit, which determines from them the angle of impact, the severity, or force of the crash, along with other variables. Depending on the result of these calculations, the ACU may also deploy various additional restraint devices, such as seat belt pre-tensioners, and/or airbags (including frontal bags for driver and front passenger, along with seat-mounted side bags, and "curtain" airbags which cover the side glass). Each restraint device is typically activated with one or more pyrotechnic devices, commonly called an initiator or electric match. The electric match, which consists of an electrical conductor wrapped in a combustible material, activates with a current pulse between 1 to 3 amperes in less than 2 milliseconds. When the conductor becomes hot enough, it ignites the combustible material, which initiates the gas generator. In a seat belt pre-tensioner, this hot gas is used to drive a piston that pulls the slack out of the seat belt. In an airbag, the initiator is used to ignite solid propellant inside the airbag inflator. The burning propellant generates inert gas which rapidly inflates the airbag in approximately 20 to 30 milliseconds. An airbag must inflate quickly in order to be fully inflated by the time the forward-traveling occupant reaches its outer surface. Typically, the decision to deploy an airbag in a frontal crash is made within 15 to 30 milliseconds after the onset of the crash, and both the driver and passenger airbags are fully inflated within approximately 60-80 milliseconds after the first moment of vehicle contact. If an airbag deploys too late or too slowly, the risk of occupant injury from contact with the inflating airbag may increase. Since more distance typically exists between the passenger and the instrument panel, the passenger airbag is larger and requires more gas to fill it.

Front airbags normally do not protect the occupants during side, rear, or rollover accidents. [27] Since airbags deploy only once and deflate quickly after the initial impact, they will not be beneficial during a subsequent collision. Safety belts help reduce the risk of injury in many types of crashes. They help to properly position occupants to maximize the airbag's benefits and they help restrain occupants during the initial and any following collisions.

In vehicles equipped with a rollover sensing system, accelerometers and gyroscopes are used to sense the onset of a rollover event. If a rollover event is determined to be imminent, side-curtain airbags are deployed to help protect the occupant from contact with the side of the vehicle interior, and also to help prevent occupant ejection as the vehicle rolls over.
[edit] Triggering conditions

Airbags are designed to deploy in frontal and near-frontal collisions more severe than a threshold defined by the regulations governing vehicle construction in whatever particular market the vehicle is intended for: U. S. regulations require deployment in crashes at least equivalent in deceleration to a 23 km/h (14 mph) barrier collision, or similarly, striking a parked car of similar size across the full front of each vehicle at about twice the speed. International regulations are performance based, rather than technology-based, so airbag deployment threshold is a function of overall vehicle design.

Unlike crash tests into barriers, real-world crashes typically occur at angles other than directly into the front of the vehicle, and the crash forces usually are not evenly distributed across the front of the vehicle. Consequently, the relative speed between a striking and struck vehicle required to deploy the airbag in a real-world crash can be much higher than an equivalent barrier crash. Because airbag sensors measure deceleration, vehicle speed and damage are not good indicators of whether an airbag should have deployed. Airbags can deploy due to the vehicle's undercarriage striking a low object protruding above the roadway due to the resulting deceleration.

The airbag sensor is a MEMS accelerometer, which is a small integrated circuit with integrated micro mechanical elements. The microscopic mechanical element moves in response to rapid deceleration, and this motion causes a change in capacitance, which is detected by the electronics on the chip that then sends a signal to fire the airbag. The most common MEMS accelerometer in use is the ADXL-50 by Analog Devices, but there are other MEMS manufacturers as well.

Initial attempts using mercury switches did not work well. Before MEMS, the primary system used to deploy airbags was called a "rolamite". A rolamite is a mechanical device, consisting of a roller suspended within a tensioned band. As a result of the particular geometry and material properties used, the roller is free to translate with little friction or hysteresis. This device was developed at Sandia National Laboratories. The rolamite, and similar macro-mechanical devices were used in airbags until the mid-1990s when they were universally replaced with MEMS.

Nearly all airbags are designed to automatically deploy in the event of a vehicle fire when temperatures reach 150-200 °C (300-400 °F). [28] This safety feature, often termed auto-ignition, helps to ensure that such temperatures do not cause an explosion of the entire airbag module.

Today, airbag triggering algorithms are becoming much more complex. They try to reduce unnecessary deployments (for example, at low speed, no shocks should trigger the airbag, to help reduce damage to the car interior in conditions where the seat belt would be an adequate safety device), and to adapt the deployment speed to the crash conditions. The algorithms are considered valuable intellectual property. Experimental algorithms may take into account such factors as the weight of the occupant, the seat location, seatbelt use, and even attempt to determine if a baby seat is present.

 

[Carlacee]

Kenny61:



As far as I know the truck rear ended a Toyota sedan on the freeway. Apprently, the truck ran right over the toyota and flipped onto the drivers side (notice how the dually fender well has been torn off).



Notice the front fender, I'm not sure how that damage ocurred but you'd have to think that that would have been enough of an impact to initiate an air bag deployment.



I also heard the truck was picked up as a repo so I have no idea if the truck had already seen a deployment prior to this accident.



FYI, the driver of the toyota was killed in the accident and the accident closed the freeway for a few hours, what a mess. I'd hate to get hit with one of these trucks if I was in a small car, thank gawd I only drive trucks now.

 

[Grizzly]

I'm really sadden to hear that the driver of the Toyota was killed.



george

 

[kenny61]

I'm guessing since it ran right over the toyota that the threshold was not crossed, regretably most of the energy was probably transfered to the other vehicle during the rear end. After the truck turned on its axis and started to roll the liekelyhood of the airbags deploying would be about zero

 

[MVenditti]

That's kind of scary that it didn't deploy. Is there any way air bags can be tested to make sure they will deploy if the need should arise?

Yes, sit in driver seat and have friend hit bumper with sledgehammer.

 

[brods]

I'm guessing since it ran right over the toyota that the threshold was not crossed, regretably most of the energy was probably transfered to the other vehicle during the rear end. After the truck turned on its axis and started to roll the liekelyhood of the airbags deploying would be about zero

Because airbag sensors measure deceleration, vehicle speed and damage are not good indicators of whether an airbag should have deployed.

Kenny has it right, deceleration rate is the key. A train recently struck a large fire truck here in Detroit and when interviewed by the news a passenger on the train likened it to hitting a speed bump. The fire truck got trashed. Same principles involved here, the more massive vehicle fares better.



As we all know the sheetmetal is pretty wimpy and the bumper isn't very tough either so it doesn't take much to tear it all up. And who knows what damage shown in the picture was caused during the recovery. It is a sad reminder that we are driving around in 4 ton wrecking balls and should always take driving safety seriously.

 

[CKESSEL]

Also, the system will not arm itself if the SEATBELT is not used. At the body shop I managed, a customer came in with his car that had the rh bag deployed but the lh was not. I asked him if he had his belt on and he said no. At least he had enough smarts to insure that his kid was strapped in properly.

 

[Grizzly]

Yes, sit in driver seat and have friend hit bumper with sledgehammer.

Don't you have better things to do?

 

[rscurtis]

Also, the system will not arm itself if the SEATBELT is not used. At the body shop I managed, a customer came in with his car that had the rh bag deployed but the lh was not. I asked him if he had his belt on and he said no. At least he had enough smarts to insure that his kid was strapped in properly.

I'd want to see something official on that. One of the reasons for the advent of air bags was to offer protection to people who weren't wearing seat belts.

 

[brods]

Frontal airbags: Frontal airbags are designed to inflate in moderate to severe frontal crashes. Among airbags with advanced features that include a safety belt sensor, there are different inflation thresholds depending on whether people are using their safety belts. One threshold used by airbag designers is "must deploy" which includes a situation such as an impact into a rigid wall of 10-12 mph for unbelted occupants. The "must deploy" threshold is slightly higher — about 16 mph — for belted occupants because the belts alone are likely to provide adequate protection up to these moderate speeds. Frontal airbags may deploy to help protect occupants in side impacts if there is sufficient forward deceleration during the crash. For example, if a vehicle is moving forward at the time of a side impact, frontal airbags can help prevent serious injuries.



Advanced airbags compliant with government crash performance standards have been required in all passenger vehicles effective with model year 2007. Advanced airbags are designed to suppress deployment if weight sensors in the seat detect that a front-seat passenger is small or in a child safety seat. Advanced airbags also can deploy at a lower energy level or pressure when passengers are small or out of position, or if the crash is of very low severity.

That would seem to indicate an airbag is more likely to deploy if the seat belt is not buckled.

 

[CKESSEL]

Not all vehicles have the seat sensor that tells the system the seat is occupied. The only way it knew is if the belt was wrapped around and clicked to engage the system.

 

[brods]

So your saying some systems need the drivers seat belt buckled when a crash occurs or the airbag module thinks nobody is driving the vehicle and doesn't deploy the airbag??? Not likely.

 

[kenny61]

I think what he meant was that the bag will not deploy due to possible increase in spinal injury without a seatbelt not because the vehicle thinks nobody is in the seat. I do not know how the Dodge system work and this question can only be answered by one of the designing engineers' who fully comprehend all the variables in the system. I believe most posters, such as I, are merely supplying possibilities as to why the bag did not deploy. Simply put the fact the bag did not deploy does not mean it was defective.

Drivers and front-seat passengers who have airbags but do not use seatbelts are much more likely to sustain a spinal injury in frontal crashes than drivers and front-seat passengers with airbags who do use seatbelts, according to a study by the Pitt School of Medicine's Department of Orthopaedic Surgery's Division of Spinal Surgery.

“If you do not wear a seatbelt, the airbag can be a weapon, a source of injury. If you do wear a seatbelt, the airbag most likely will be helpful,” said study coauthor William F. Donaldson III, a Pitt associate professor of orthopaedic surgery and neurological surgery and chief of the Division of Spinal Surgery. “By not buckling your seatbelt, you increase the likelihood of a spinal fracture and spinal cord injury when your airbag deploys in a frontal collision. ”

The research team studied the outcomes of 86,000 patients who were drivers or passengers in frontal collisions occurring in Pennsylvania between 1990 and 2002, according to data from the Pennsylvania Trauma Systems Foundation.

Drivers who had airbags but were not wearing seatbelts were 1. 7 times more likely to sustain a cervical spine fracture and 2. 4 times more likely to have a spinal cord injury than those drivers who used airbags and seatbelts. Front-seat passengers had even more significant results: The passengers with airbags alone and no seatbelt restraint were 6. 7 times more likely to sustain a fracture with spinal cord injury than those passengers who were protected with an airbag and seatbelt.

“What prompted us to do the study was the number of injuries we were seeing in the UPMC orthopaedic spine clinic that we attributed to potentially out-of-position and unrestrained victims of motor vehicle crashes in which airbag deployment may have caused spinal injury,” said Donaldson. “This concerns us, because 25 percent of Pennsylvania drivers still do not wear seatbelts regularly. ”

Although airbags are credited with saving thousands of lives and preventing thousands of serious injuries each year, the safety of airbags revolves around proper use, according to Donaldson. “Hundreds of cases of serious injury and deaths have occurred when car occupants were unrestrained and in an unplanned position or were too close to the airbag when it deployed during a crash,” he said. The airbag deploys at about 140 to 220 miles per hour and rapidly deflates.

Of the 86,000 patients studied, 12,678 had spinal injuries and 5,506 had cervical spine injuries. Of those 5,506, 203 used both airbags and seatbelts, 187 used an airbag only, 1,658 used a seatbelt only, and 3,458 were unprotected. The drivers who were unbelted with no airbag were 1. 3 times more likely to have a cervical spine fracture and 1. 8 times more likely to sustain a cervical spine fracture with a spinal cord injury than those drivers who were protected by both an airbag and seatbelt. As for the passengers who were unbelted with no airbag, they were 7. 9 times more likely to have a fracture with spinal cord injury compared to those passengers with airbags and seatbelts.

“Fortunately, new airbag technology that will improve various aspects of the effectiveness and safety of the airbags is on the horizon, but even new technological advances cannot replace common sense—a person needs to buckle their seatbelt,” said Donaldson.