Mr. Paul Schockmel
International Electronics and Engineering S.A.
Zone Industrielle Findel
2b, route de Treves
Dear Mr. Schmockmel:
This responds to your letter requesting an interpretation of the advanced air bag requirements of Federal Motor Vehicle Safety Standard No. 208, Occupant crash protection (FMVSS No. 208). On May 12, 2000, the National Highway Traffic Safety Administration (NHTSA) published a final rule in the Federal Register (65 FR 30680) requiring advanced air bags in all passenger cars, multipurpose passenger vehicles, light trucks and buses with a gross vehicle weight rating (GVWR) of 8,500 lb or less. The phase-in for these new requirements begins September 1, 2003. That final rule established new, advanced air bag performance requirements to minimize the risk of injury to children, as well as new requirements to enhance protection of small and mid-size adults. The requirements in S19, S21, and S23 are designed to minimize the risk that air bags pose to infants and small children. S19 provides manufacturers with two different options for complying with the standard (low risk deployment or automatic suppression), while S21 and S23 provide three options (low risk deployment, automatic suppression, or dynamic automatic suppression). Your questions are related to the interplay between the infant low risk deployment option and the infant automatic suppression option, particularly in light of the absence of a dynamic automatic suppression option for infants. I am pleased to provide a response.
You first request an interpretation of the requirement set forth in S19, and the test procedure provided in S20.4, relating to the low risk deployment option for infants. Specifically, you ask whether a system that is certified to the low risk deployment option for infants can suppress the air bag when the applicable child restraint is in the rear-facing mode, and either suppress or deploy when the restraint is placed in the forward-facing mode. The answer to the first part of this question is no. Under the low risk deployment option, one or more stages of the air bag must deploy when the restraint is rear-facing. The answer to the second part of your question is yes. If a system is certified to the low risk deployment option for infants, we will deploy the air bag as specified in S20.4. Thus, injury measurements are only recorded when the child restraint is in the rear-facing mode.
The requirements for the infant low risk deployment option are found at S19.3, which states that "each vehicle shall meet the injury criteria specified in S19.4 of this standard when the passenger air bag is deployed in accordance with the procedures specified in S20.4." The low risk deployment option is designed to address injuries that can result when an infant is very close to the air bag.
S20.4 specifies several conditions for testing the deploying air bag. First, the manufacturer must assure compliance to S19.3 using any child restraint listed in subparts B and C of Appendix A to the standard. For purposes of S19.3, the air bag is only tested with the child restraints in their rear-facing condition. Under the specified test conditions, the vehicle seat is moved as far forward as possible, while avoiding contact with the vehicle interior. This is done to ensure that the dummy's head is placed as close to the deploying air bag as possible. The air bag is only tested with the child restraint in a belted condition.
The air bag is deployed at whatever level of force and combination of stages that would deploy in any rigid barrier crash up to 64 km/h (40 mph) when a test dummy is positioned in a restraint as specified in the test procedure, except that the vehicle seat may be at any seat track position. This level is determined by running an indicant test, as described in S20.4.9, at impact speeds up to 40 mph with a dummy-occupied restraint installed in the passenger seat.
When NHTSA runs a compliance test on a vehicle certified to S19.3, it will only deploy the air bag at the level and, if equipped with a multi-stage inflator, with the combination of stages, that would deploy in the specified indicant test. Manufacturers may not use suppression technology to ensure that there will be no air bag deployment in the indicant test if they are certifying to the low risk deployment option.
Your second question relates to the absence of a dynamic automatic suppression option in S19. Specifically, you ask whether a manufacturer may use a system whereby the air bag is suppressed in all but the forward-facing mode, where a benign deployment strategy would be used. This option is not currently allowed under S19. This is because such a system would not meet either the low risk deployment option or the automatic suppression option. Should the agency add a third, dynamic suppression option to S19, such a compliance strategy would be allowed as long as all the criteria of that option were met in full.
I hope this letter addresses your concerns. Please feel free to contact Rebecca MacPherson of my staff at (202) 366-2992 should you have any additional questions.