Interpretation ID: aiam4149
Jr.
Esq.
Curtis
Bamburg & Crossen
Attorneys at Law
230 South Bemiston
St. Louis
MO 63105;
Dear Mr. Hutton: This responds to your letter asking about inertial-locking seatbelt and seatbacks. We apologize for the delay in our response. You stated that your firm represents a woman who was injured in a 1982 Ford Escort GT. According to your letter, while braking to exit a highway, the driver's seatback was thrown forward, not locking, causing your client to lose control of the car and crash into a guardrail. You asked for information about inertial-lock mechanisms on automobiles, particularly for seat backs and belts in that car, and references to government safety standards. You specifically asked whether there was a standard for the maximum distance the seatback can travel before locking under load.; The National Highway Traffic Safety Administration (NHTSA) issue Federal motor vehicle safety standards, pursuant to the National Traffic and Motor Vehicle Safety Act. Two of our standards are relevant to inertial-lock mechanisms.; Federal Motor Vehicle Safety Standard No. 209, *Seat Belt Assemblies* specifies requirements for inertial-locking safety belts. Section S4.3(j) specifies the following:; >>>(j) *Emergency-locking retractor*. An emergency-locking retractor o a Type 1 or Type 2 seat belt assembly, when tested in accordance with the procedures specified in paragraph S5.2(j)--; (1) Shall lock before the webbing extends 1 inch when the retractor i subject to an acceleration of 0.7 g. . . .<<<; Thus, for safety belts, there is a specific requirement for the maximu distance the webbing may extend before locking under load.; Federal Motor Vehicle Safety Standard No. 207, *Seating Systems* (4 CFR S571.207), specifies requirements for restraining devices for hinged or folding seats and seat backs. See section S4.3. The standard requires that such seats be equipped with self-locking restraining devices, and specifies both static force and acceleration performance requirements which the restraining devices must meet once engaged. However, the standard does not specify either the load at which an inertial-locking seatback must lock or the maximum distance the seatback can travel before locking under load.; In response to your request for information that relates to th particular car involved in your client's accident, we have enclosed a computer printout listing relevant vehicle owner reports which allege problems similar to that identified by your letter.; I hope this information is helpful. There is no fee for th information.; Sincerely, Erika Z. Jones, Chief Counsel