Interpretation ID: nht72-3.49

DATE: 09/05/72

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Volkswagen of America, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of June 26, 1972, on the subject of the conformity of the Volkswagen shoulder belt/knee bar system to the requirement of Standard No. 208. I apologize for our delay.

Your first question is whether the system would meet the requirements for a fully passive system under S4.1.2.1 and S4.1.3 if it were adjusted automatically and met the frontal and lateral crash protection requirements if S5.1 and S5.2 and if the vehicle conformed to Standard 216. Our reply is that a passive seat belt system of the type you describe would appear to satisfy the requirements of S4.1.2.1 and S4.1.3. It would also, however, be required to meet the requirements of S4.5.3. We cannot determine from your description whether the system is capable of fitting the range of occupants specified in S7.1, as required by S4.5.3.3.

Your second question concerns the possibility that the system could be used, with the shoulder belt either active or passive, to meet the second or third option for passenger cars manufactured between August 15, 1973, and August 15, 1975. You point to two variances between the Volkswagen system and the system contemplated by these options. S4.1.2.2 requires the installation of a Type 1 seat belt, whereas the Volkswagen system contains only a shoulder belt and a knee bar. S4.1.2.3 specifies either a Type 1 or a Type 2 seat belt assembly, neither of which is found in the Volkswagen system. It is our opinion that these variances are such that an amendment of the standard would be required to permit the use of the Volkswagen system under either S4.1.2.2 or S4.1.2.3.

With reference to both the passive system discussed in your first question and a petition for rulemaking in connection with your second, we are particularly concerned with the actual crash performance of a single diagonal belt restraint as opposed to the Type 1 or Type 2 belts permitted in Standard No. 208. The injury criteria presently included in Standard No. 208 may not differentiate between restraint systems with good crash force distribution, such as the air cushion, and those such as the single diagonal belt which could poorly distribute loads on real human occupants. Accordingly, we would appreciate your sending us accident data describing experience with the European type single diagonal belt.