Interpretation ID: nht88-1.77

TYPE: INTERPRETATION-NHTSA

DATE: 03/21/88

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: Robert A. Rogers -- Director, Automotive Safety Engineering, General Motors Corporation

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Robert A. Rogers Director, Automotive Safety Engineering General Motors Corporation General Motors Technical Center 30400 Mound Road Warren MI 48090-9015

Dear Mr. Rogers.

This respond to your recent letter seeking an interpretation of Standard No. 209, Seat Belt Assemblies (49 CFa 5571.209). Specifically, you stated that you believe that Standard No. 209 does not specifically address remotely actuated emergency-locking re tractors. You explained that you were referring to retractors that are actuated by a deceleration sensor that is located some distance from the retractor itself. You stated that the existing uncertainty discourage; vehicle manufacturers from considering the introduction of this technology. Additionally your letter claims that it is not clear whether the test procedures in Standard No. 209 are compatible with remote s ensors. NHTSA does not agree that there are existing uncertainties with respect to the applicability of Standard No. 209 to remotely actuated retractors.

The agency first addressed this issue many years back. In a letter to Mr. Nakajima of Toyota, dated March 16,1973 (copy enclosed), NHTSA explained that Standard No. 209 does address the issue of remotely actuated retractors. In that letter, we explained that both the remotely located sensor(s) and the individual solenoids, or other actuating devices on the retractor mechanism itself, would be considered seat belt assembly hardware for the purposes of Standard No. 209. All assembly hardware must be certi fied as complying with the requirements of S4.3 of Standard No. 209, including corrosion resistance and temperature resistance. This 1973 letter is still an accurate expression of the agency's opinion on this subject. Accordingly, there is no need to ini tiate rulemaking for Standard No. 209 to "ensure compatibility with the remotely actuated retractor concept."

If you have any further questions or need more information on this subject please contact Steve Kratzke of my staff at this address or by telephone at (202) 366-2992.

Sincerely,

Erika Z. Jones Chief Counsel

Enclosure

January 26, 1988

Erika Z. Jones Chief Counsel National Highway Traffic Safety Administration 400 Seventh St., S. W. Washington, D. C. 20590

Dear Ms. Jones:

On December 1, 1987, representatives from General Motors (GM) and TRW participated in discussions with NHTSA relative to the concept of externally remotely actuated emergency-locking retractors as it might be applied to future seat belt assemblies. At th at time, GM noted that FMVSS 209 does not specifically address a retractor which is actuated by an electrical signal from a remotely located deceleration sensor. This omission introduces a regulatory uncertainty which discourages vehicle manufacturers fr om considering the incorporation of this relatively new technology into their restraint planning. Further, it is unclear whether or not the test procedures contained in FMVSS 249 are compatible with remote sensing. With this letter, we are requesting tha t the agency: 1) provide an interpretation affirming the regulatory permissibility of seat belt assemblies that incorporate remotely actuated emergency locking retractors, and 2) initiate rulemaking, if necessary, aimed at ensuring the compatibility of t he FMVSS 209 hardware and assembly test requirements and the remotely actuated seat belt retractor concept.

As the GM representatives noted in the December meeting, a strong case can be made for the position that FMVSS 209 currently provides for the use of remotely actuated retractors. There do not appear to be restrictions in the FMVSS 209 definition of seat belt assembly" which would preclude the use of specific seat belt assembly designs. Further, FMVSS 209 defines an emergency-locking retractor as one, "incorporating adjustment hardware by means of a locking mechanism that is activated by vehicle accelera tion, webbing movement relative to the vehicle, or other automatic action during an emergency and is capable when locked of withstanding restraint forces. We believe that this definition applies to a remotely actuated retractor.

There was general agreement among those in attendance at the December meeting that use of the term "retractor in the FMVSS 209 test procedures that apply (S4.3 and S5.2) could be interpreted logically to be a short hand notation for "retractor sub-system " . Such an interpretation is supported by the fact that neither the regulatory history of FMVSS 209 nor SAE J4c, which served as the basis for FMVSS 209, reference a need to restrict the design of retractors to ones with "built-in " mechanical sensing m echanisms. This view further supports a position that no restrictions have been or were intended to be placed on retractor designs given that the performance requirements of FMVSS 209 could be met.

It is our understanding based on discussions with TRW personnel that remotely actuated retractors can be designed to meet all existing FMVSS 209 performance requirements, including sensitivity. In fact, research to date suggests that the threshold sensit ivity of a retractor actuated by an electrical signal from a remote sensor exceeds that achievable with a retractor which incorporates a built-in mechanical pendulum. Thus, no easing of FMVSS 209 requirements would be needed to enable vehicle manufacture rs to include remotely actuated retractors in their restraint planning. Nor would special considerations be needed to encourage vehicle manufacturers to fully investigate the potential of remote sensing. As noted in TRW's discussion paper which was submi tted to NHTSA after the December meeting (copy attached), remote sensing offers significant potential for retractor downsizing and optimization of retractor locations--important factors in vehicle restraint design. Manufactures may also find further ince ntives when the flexibility offered by retractors which activate by electrical signals from remotely placed sensors is fully analyzed.

GM considers this request to be important because it relates to the compatibility of existing safety requirements with new and emerging technology. It is our understanding that agency policy dictates that its rulemaking not be technology limiting. on tha t basis, we request that NHTSA provide an interpretation that FMVSS 209 currently accommodates seat belt assemblies that incorporate remotely actuated retractors. Consistent with such an interpretation, we request that the agency review the hardware and assembly test requirements of FMVSS 209 for the purpose of ensuring compatibility with the remotely actuated retractor concept.

Finally, GM believes that time is of the essence and urges NHTSA to expedite its action on this request. Toward that end, we stand ready to provide any additional information at our disposal that