Interpretation ID: nht93-3.49

DATE: May 17, 1993

FROM: Ron D. Belk -- President, Kustom Fit

TO: John Womack -- Acting Chief Counsel, NHTSA

COPYEE: J. Gonzalez; B. Barras; G. Slee; E. Belk

TITLE: None

ATTACHMT: Attached to letter dated 8/16/93 from John Womack to Ron D. Belk (A41; Std. 209; Std. 208)

TEXT:

Thank you for your letter concerning certification of FMVSS 208. Your explanation of "Self-certification" and "Due Care" is helpful in our efforts to comply with all Federal Safety Standards that apply to seating systems, especially in light trucks. However, we still need your further assistance to feel totally comfortable with our "Due Care and self-certification." Our last letter to you asked about a factory "Baseline" sled test as a comparison to our own component test. Your letter has explained NHTSA's position on that. What we don't understand yet is the relationship we have as a seating manufacturer to uncontrollable factors within the "Restraint System" to comply with FMVSS 208. In this instance, our uncontrollable factor is the "Seat Belt Payout" as it relates to (HIC) levels and (Chest "G") force. Our analysis has pointed us in a particular area which is the seat belt pay out dimension from the data we have received. I'll try to explain this. The seat belt pay out is inconsistent comparing all three tests. See our "G" van sled test comparison sheet, attached.

This data was further compared by my Engineering Manager, Mr. Jose Gonzalez and is also attached. Please read this written analysis before you go further. This comparison relates to the impact of "Seat Belt Pay Out" to (HIC) levels and (Chest "G") force. His findings show that the inconsistencies of belt pay out (2.25 inches to 4.9 inches) definitely contributes to the success or failure of these two very important injury criteria. We don't manufacture the seat belts. How do we qualify the test with belt pay out variables such as these? Does FMVSS 209 allow for this 2.65 inch variance? Are we expected to pass these injury criteria even though the belt pays out from 2.25 inches to 4.9 inches from test to test? How do I show my customer, the van converter, that I've passed these criteria? If I had unlimited funds I suppose I could keep running sled tests until the belt pays out just the right amount. But that's not what we should have to do. We need a test report that shows we passed these injury criteria. Is our comparison "Baseline to Kustom Fit test" acceptable? Furthermore, we want to know where you stand from a compliance standpoint on this issue "Seat vs. Seatbelt."

For example, If NHTSA crashes a "G" van and the belt pay out is below or above my engineer's allowable length and the (HIC) level and (Chest "G") forces are above NHTSA's standards, is NHTSA going to analyze the data as we have or will they pose the liability on the seating or seat belt manufacturer?

We need your response to this situation as soon as possible.

Attachment

(Kustom Fit test data omitted.)