Interpretation ID: 2890o
Thorne, Grodnik & Ransel
228 West High Street
Elkhart, IN 46516-3176
Dear Mr. Duncan:
This responds to your letter concerning situations in which seats tested for compliance with Safety Standard No. 207, Seating Systems, bend or deform when subjected to the required test forces specified in the standard. You asked whether NHTSA would consider a seat as passing Standard No. 207 if the seat "gives," but does not separate or break free from the floor. I regret the delay in responding.
The requirements with which you are concerned are set forth in section S4.2 of Standard No. 207. That section provides in pertinent part:
S4.2 General performance requirements. When tested in accordance with S5., each occupant seat, other than a side-facing seat or a passenger seat on a bus, shall withstand the following forces.
(a) In any position to which it can be adjusted--20 times the weight on the seat applied in a forward longitudinal direction;
(b) In any position to which it can be adjusted--20 times the weight on the seat applied in a rearward longitudinal direction;
* * * * *
(d) In its rearmost position--a force that produces a 3,300 inch-pound moment about the seating reference point for each designated seating position that the seat provides, applied to the upper cross-member of the seat back or the upper seat back, in a rearward longitudinal direction for forward-facing seats and in a forward longitudinal direction for rearward-facing seats.
The agency answered similar questions in letters dated April 28, 1977 and August 30, 1979 to Mr. Gordon P. Cress and to Mr.Robert Wahls, respectively. (Copies enclosed.) In these letters, the agency stated that NHTSA allows some deformation of the seats during the force test, provided that "structural integrity of the seats is maintained." The structural integrity of a seat is determined by the extent to which permanent deformation or separation of seat components and/or seat to floor attachments result from the applied test forces. Examples of possible noncompliances include the following occurring during the application of a forward or rearward load:
(a) the seat frame releases from its adjusted position;
(b) the seat frame or seat adjusters detach from the test vehicle floorpan;
(c) the seat frame detaches from the seat adjuster mechanism;
(d) the seat adjuster mechanism separates; or,
(e) the hinged seat restraining device disengages, or detaches from the seat frame.
Other examples of possible noncompliances are the rear seat back or cushion frame detaching from the test vehicle structure during the application of the specified load, or the folding seat back restraining device releasing from its preset position during application of a forward load.
Further, as stated in the two enclosed letters, it has been the longstanding position of the agency that seats which displace to an extent that NHTSA determines occupant safety is threatened would not be in compliance with Standard No. 207.
I hope this information is helpful. Please contact my office if you have further questions.
Sincerely,
Erika Z. Jones Chief Counsel
Enclosures ref:207 d:8/26/88