Interpretation ID: nht95-3.13

TYPE: INTERPRETATION-NHTSA

DATE: June 14, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: A. P. Corrado -- Director, Market Development, GenCorp Aerojet Electronic Systems Division

TITLE: NONE

ATTACHMT: ATTACHED TO 4/25/95 LETTER FROM A. P. CORRADO TO JOHN WOMACK

TEXT: Dear Mr. Corrado:

This responds to your letter requesting clarification of the requirements of Standard No. 208, Occupant Crash Protection, with respect to automatic cut-off devices for air bags. You requested confirmation that the standard "does not preclude the use of inflatable restraint systems that by design inhibit deployment of a passenger air bag in those identifiable cases where the likelihood and severity of passenger injury would be greater with air bag deployment than without." You specifically cited the cas e of out-of-position passengers. As discussed below, Standard No. 208 does 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 con ditions specified in the standard.

NHTSA addressed the legality of both automatic and manual air bag cutoff devices in the context of a recent rulemaking to permit manual cutoff devices under special circumstances. In a notice of proposed rulemaking (NPRM) published in October 1994, the agency explained that automatic cutoff devices for passenger side air bags are already permitted by Standard No. 208. However, the devices must be designed to automatically ensure that the air bag is activated under the dynamic crash test conditions spe cified in the standard, i.e., in a 30 mph barrier crash test, with a 50th percentile male dummy properly positioned in the seat. See discussion at 59 FR 51160, October 7, 1994. I have enclosed a copy of that notice for your information, as well as a co py of the recently issued final rule.

I would like to note a safety issue that is relevant to the design of automatic cutoff devices for air bags. Standard No. 208's requirements for air bags are intended to provide safety benefits for a much broader set of real world conditions than the na rrow conditions specified in the standard's dynamic crash test, i.e., at a greater number of speeds and frontal impact angles, for many different sizes of occupants, etc. The agency recognizes the safety benefits that can be provided by well-designed au tomatic cutoff devices that can sense rear facing infant restraints and other possible special situations where deactivation is appropriate. At the same time, NHTSA believes it is important for manufacturers developing automatic cutoff devices to ensure that the devices do not deactivate air bags under circumstances where the air bags would provide important safety benefits.

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 this address or at (202) 366-2992.