Mr. Michael Love
Manager, Compliance
Porsche Cars North America, Inc.
100 West Liberty Street
P.O. Box 30911
Reno, Nevada 89520-3911

Dear Mr. Love:

This responds to your letter concerning the requirements of Standard No. 208, AOccupant Crash Protection,@ with respect to cut-off devices for air bags. Your letter addresses NHTSA's May 1995 final rule in which we decided to permit manufacturers, until September 1, 1997, the option of installing a manual device that motorists could use to deactivate the front passenger-side air bag in certain passenger cars.

You ask whether a system you have developed "qualif[ies] as an automatic cutoff, and therefore should be permissible under FMVSS 208." The following discussion explains that the system you describe is permissible under FMVSS 208 and that it is unnecessary to determine whether the system is "automatic."

You described your system as consisting of:

. . . a special rearward-facing child seat which, when properly installed in the vehicle, disables the passenger airbag. . . . Attached to the child seat is a special strap and buckle tongue. The vehicle is equipped with a buckle receiver installed under the front of the passenger seat (installed upon request by a Porsche dealer). When the buckle tongue is inserted into the buckle receiver, a signal is sent to the airbag control unit disabling the passenger airbag. Since the disablement function is engaged during the process of installing the child seat in the car, and is disengaged as part of the process of removing the child seat from the car, we believe it qualifies as Aautomatic.@

You also stated that Asince the special buckle is permanently attached to the child seat, the air bag can be disabled only when the child seat is properly installed,@ and that Athe buckle is different from the other seat belt buckles used by Porsche, so disablement of the air bag using a normal seat belt is not possible.@

In analyzing whether your device is permissible under Standard No. 208, it is not necessary to determine whether the device is "automatic" or "manual." That dichotomy, which was used by the agency in previous discussions of cutoff devices, simply reflects an underlying inquiry as to whether a given cutoff device would create the possibility of a vehicle being tested under Standard No. 208 both with the device in the on position and with the device in the off position. The particular manual devices considered by the agency during its rulemaking all created that possibility. Your device, whether "manual" or "automatic," does not raise that possibility.

Prior to the rulemaking to permit certain manual cutoff devices, Standard No. 208 did not explicitly address cutoff devices. The issue arose in response to growing concern about the danger to infants in rear-facing child seats from passenger side air bags. The possibility of manufacturers providing certain kinds of manual cutoff devices (e.g., on-off switches) raised a test condition issue. The standard=s dynamic crash test could be run with the device on or off, and the issue was which way the test should be run. Based on the language and purposes of Standard No. 208, NHTSA concluded that the dynamic crash test requirement must be met regardless of whether a manual cutoff device was on or off. Since the standard=s crash test requirements presumably could not be met with the air bag deactivated, the standard effectively prohibited these manual cutoff devices. See 59 FR 51160, October 7, 1994.

Based on the information provided in your letter, a vehicle equipped with your system would not be tested with the air bag deactivated. Your device operates in a fundamentally different manner from the type of manual device discussed in the recent rulemaking. This is because, with your device, the only situation in which an air bag would be deactivated is when a child seat is located in the front seat. Since the Standard No. 208 test is conducted only with a 50th percentile male dummy located in the front seat, a vehicle equipped with your device could satisfy Standard No. 208 without creating the possibility of a test condition in which the air bag is deactivated.

It is true that this result is consistent with the agency's description of devices we characterized as "automatic." In the October 1994 notice, NHTSA explained that "automatic" cutoff devices were allowed by Standard No. 208. The agency contemplated that Amanufacturers would design these devices so that they would automatically ensure that the front passenger air bag is activated during the barrier crash test. . . [whenever]. . . a 50th percentile adult male dummy is in the front seat.@ So while there is the similarity that Standard No. 208 would be met without two possible test conditions, our concept of "automatic" presupposed a system meeting the Standard No. 208 tests with the 50th percentile male dummy in the front seat.

Similarly, as NHTSA explained in a June 14, 1995, letter to GenCorp Aerojet, Standard No. 208 Adoes not preclude the use of automatic cutoff devices for passenger air bags, so long as the devices ensure that the air bag automatically deploys under the specific dynamic crash conditions specified in the standard.@ The agency noted that these conditions include a specified barrier crash test, with a 50th percentile male dummy properly positioned in the seat.

I should add that the rear-facing child seat you describe is a Achild restraint system@ as defined in Standard 213, AChild Restraint Systems@ (49 CFR '571.213), and thus subject to all applicable requirements of that standard. Further, in a compliance test governed by the requirements of Standard 213, NHTSA will test the child restraint using only a vehicle lap belt to attach the system to the standard seat assembly used for such tests. The special strap and buckle will not be attached. (See S5.3.2 and S6.

I would like to conclude by noting that, in our rulemaking to permit manual cutoff devices, we decided to permit such devices for only a limited period of time. In the intervening time, we believed it was possible that manufacturers could develop and introduce fully automatic cutoff devices, i.e., ones that would work without any action by the driver and for all rear facing infant restraints, as well as in other special situations where it would be beneficial to deactivate the air bag. We remain hopeful that such systems will be introduced in the foreseeable future. In the short term, however, we recognize that a system such as the one you describe could provide safety benefits. While drivers would need a special infant restraint with an extra buckle and would need to remember to latch the buckle, the system would provide a means by which the driver could deactivate the air bag while transporting a rear facing infant restraint in the front seat.

I hope this information is helpful to you. If you have any further questions or need additional information, please feel free to contact Mr. Edward Glancy of my staff at the above address or at (202) 366-2992.


Samuel J. Dubbin Chief Counsel ref:208 d:3/15/96