Join the Car Talk Community!

Discussion Rules

Welcome to the Car Talk Community!

Want to ask a question or join the discussion? Great! Join now.

Sign In Register

Airbags didn't deploy in front end collision?

edited November -1 in General Discussion
I was recently in an accident with my 2007 Honda Accord ... a woman ran a red light in front of me, and I didn't have time to stop, so I hit her front left tire / fender area. She was driving an Explorer.

I have estimated my speed on impact to be between 20 and 30, and I hit her just about squarely ... there is a bit more damage on the driver's side of the front end than the passenger's side, I think because she was making a left-hand turn, so she wasn't quite perpendicular to my vehicle.

Anyway ... I'm curious as to an explanation of why my airbags didn't deploy? Thoughts? From the force of the impact, I would assume that they'd have deployed.
Tagged:
«1

Comments

  • edited September 2010
    Was the SRS light displayed on your dash prior to the accident?
  • edited September 2010
    I have seen several frontal wrecked vehicles that did not deploy the airbags. I found some interesting info on the internet concerning airbag deployment. An algorithm is used to determine if an airbag will or will not operate during a frontal crash.

    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 say a barrier crash. Because airbag sensors measure deceleration, vehicle speed is not a good indicator of whether an airbag will deploy.

    What this all boils down to is that the airbag computer, using all the information fed into it during the crash, determines whether or not an airbag will deploy. I learned something today. Thanks for your question.
  • edited September 2010
    AL - no, the srs light wasn't on prior to the accident
    missileman - interesting. maybe that explains it, since the collision wasn't completely evenly distributed across the vehicle ... but how often ARE collisions evenly distributed? this is really discouraging to me, considering the force of the impact, and how severely my head / neck were thrown forward. at least my seat belt worked, and saved me from significant injury.
  • edited September 2010
    I guess we should all double check our seatbelts since the airbags are at the mercy of a computer's algorithmic computations. The engineers are the pros when it comes to designing these systems but I'm now wondering where the fine line is between the airbags working or not working. The "gray" area always bothers me a little but I'm glad the airbags are there at least. I have had a couple of family members and friends who have walked away after a bad crash and the airbags worked as advertised.
  • edited September 2010
    I would agree ... I'm glad they are there, in case of a very serious crash, but I'm concerned about the gray area. I have also been told, though, that airbags can cause you different injuries ... burns, bruises, broken nose ... so maybe I should just be thankful and move on ...
    I'm with you, though ... they have been shown to save lives in certain crashes, so I'm glad to have them as a backup.
  • edited September 2010
    the airbag is not going to stop your head and neck from being thrown forward. It's going to stop your chest from getting thrashed on the steering wheel. Go look at a video of an airbag deployment test. Fully inflated, it's nowhere near where your head is when you're driving.

    The airbag most likely did not deploy because the computer did not order it. In some situations an airbag deploy can do more harm than good. The computer is programmed to not deploy it in those situations. The fact that you walked away from the wreck without significant injury tells me that the safety systems did what they were supposed to do.
  • edited September 2010
    In the event of a nonperpendicular crash with a movable object, like another car, between 20 and 30 mph, had the airbags deployed, they would have done more harm than good to you, and done more unnecessary and very expensive damage to your car. If you had been going, say, 45mph, then the airbags may have deployed. As mentioned before, they are designed to prevent your body and head from being thrown into the steering column or dashboard, and vice versa. They operated as intended, and you should probably be thankful they did not deploy in this relatively low speed crash. You are not alone, though, in misunderstanding the way airbags are designed to work. A couple years ago, my sister and her fiance were involved in a single vehicle accident. He fell asleep at the wheel, crossed over three lanes of traffic, sent the car airborne fifteen feet off the ground, and the car landed on its wheels in a field. This happened at 65mph. They walked away from the accident, but not without some minor injuries. Afterward, my sister was having a fit that the airbags didn't deploy, and I had to explain to her as well that, in this kind of accident, the airbags would not have helped, and would probably have left them with more injuries. It takes serious frontal blunt force to get the airbags to deploy. I have heard something like 31mph to zero in an instant (like hitting a concrete wall) will deploy the airbags in most cars.
  • edited September 2010
    The airbags probably would have deployed if you weren't wearing your seat belt, but you are better off with the seat belt on. If the impact had been worse, the airbags would have blown, and your car would have been totaled. As it is, make sure that they replace the driver's seat belt assembly. It is good for one crash only. The same goes for any passenger belts that were in use (if you had passengers).
  • edited October 2010
    I have seen on several occasions bags that have not blown because of sensor location. Sensors can be located high on the radiator support or low on the frame horns. I have inspected cars that hit the back of semi trailers and everything above the vehicles grille was knocked halfway into the engine compartment. The bag sensors were mounted low on the frame horns and the bags did not blow. Same thing happened with rollovers, some bags dont blow.
  • edited October 2010
    As the saying goes, speed does not kill. People don't die just because they fly at twice the speed of sound. The rate of change in speed is what kills people. When you hit that Explorer, your car probably pivoted around the front corner and went sideways for a little bit before it skid to a stop. The impact slowed you down, but not enough to warrant impact deployment. If you were going faster or if you hit it squarely on the front (meaning no way for the vehicle to rotate in any direction), then the change in speed would be enough to warrant airbag deployment.

    Also, like other posters said, wear your seat belt. Airbags are designed to fully inflate before you make contact with it. It acts as a air cushion in that manner. If you're not wearing your seat belt, you are flying toward the airbag's path of inflation. In that case, the airbag is a bomb to you.
This discussion has been closed.