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Interpretation ID: 24256ogm


    Doris Schaller-Schnedl, Homologation Engineer
    Magna Steyr Engineering
    Steyr Daimler Puch Fahrzeugtechnik AG & Co KG
    Liebenauer Hauptstrasse 317
    A-8041
    Graz, Austria


    Dear Ms. Schaller-Schnedl:

    This responds to your electronic mail message in which you indicate that your company would like to install Type 2 seat belts equipped with load limiters for use in the rear outboard seating positions of a passenger vehicle. Your message notes that you would like to employ load limiters as you believe that the devices would help reduce the possibility of injury in a crash. You indicate, however, that if you equip the seat belts in question with load limiters, the belts will not comply with the minimum performance requirements for belt elongation found in Federal Motor Vehicle Safety Standard No. 209, Seat Belt Assemblies. Your message also indicates your belief that S4.5(b) of Standard No. 209 provides that belts equipped with load limiters need not meet the elongation requirements if these belts are installed in any designated seating position that is subject to the requirements of S5.1 of Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection. As your message observes that S5.1 applies only to front outboard designated seating positions, you ask if load limiters that do not meet the elongation requirements of Standard No. 209 may only be installed in front outboard designated seating positions. Finally, if it is the agency's position that load limiter equipped belts may only be installed in the front outboard seating positions, you ask if belts equipped with these devices may be installed in rear outboard seating positions if the belts meet the performance requirements of S5.1 of Standard No. 208 when tested with a dummy placed in the rear outboard seating position.

    For the reasons explained below, load limiters that cause a seat belt to not meet the elongation requirements of Standard No. 209 may not be installed in seating positions other than the front outboard seating positions.

    Standard No. 209 establishes minimum performance requirements for seat belts and contains a number of provisions relating to elongation in seat belts and seat belt assemblies. The elongation of belt webbing is governed by S4.2(c), while the elongation performance of Type 1 and Type 2 belt assemblies is controlled by S4.4(a)(2), S4.4(b)(4) and S4.4(b)(5).

    Load limiters are intended to manage the forces imposed on an occupant when the occupant moves forward against the belt during a crash. To achieve this purpose, load limiters allow the belt to yield, in a controlled fashion, to the forces generated by restraining an occupant. In order to allow the use of load limiters while ensuring that belts equipped with the devices continue to provide a minimum level of safety, S4.5 of Standard No. 209 provides as follows:

    S4.5 Load-limiter.

    (a) A Type 1 or Type 2 seat belt assembly that includes a load-limiter is not required to comply with the elongation requirements of S4.2(c), S4.4(a)(2), S4.4(b)(4) or S4.4(b)(5).

    (b) A seat belt assembly that includes a load limiter and that does not comply with the elongation requirements of this standard may be installed in motor vehicles at any designated seating position that is subject to the requirements of S5.1 of Standard No. 208 ( 571.208).

    As you observe in your message, S4.5 provides that a seat belt equipped with a load limiter is not subject to the elongation requirements of Standard No. 209 if that belt is installed at a designated seating position that is subject to the requirements of S5.1 of Standard No. 208. S5.1 establishes the minimum performance standards for occupant protection in a frontal crash and includes, in S5.1.1, the requirements for performance in a 48 km/h (30 mph) frontal crash test employing a 50th percentile male dummy secured by a Type 2 belt in a front outboard seating position. Because the requirements of S5.1.1 provide assurance that seat belts will provide a minimum level of safety in a frontal crash, S4.5 of Standard No. 209 excludes belts with load limiters from meeting the elongation requirements of Standard No. 209 for any seating position that is tested under S5.1. As S5.1 applies only to front outboard seating positions, belts with load limiters installed at rear outboard seating positions must meet the elongation requirements of Standard No. 209.

    Your message also asks if a manufacturer wishing to install belts with load limiters in a rear outboard seating position may comply with S4.5 of Standard No. 209 by verifying the performance of the belts through testing the belts by performing testing as set forth in S5.1 on the rear outboard seats. The answer is that belts installed at rear seating positions are subject to the elongation requirements and must meet them.

    If you have any questions, please contact Otto Matheke of my staff at (202) 366-5263.

    Sincerely,

    Jacqueline Glassman
    Chief Counsel

    ref:209
    d.9/19/01