Interpretation ID: aiam2561
Chief
Structures & Test
Weber Aircraft
2820 Ontario Street
Burbank
CA 91505;
Dear Mr. Cress: This responds to your letter of February 25, 1977, requesting a interpretation concerning the force requirements specified in Safety Standard No. 207, *Seating Systems*, and Safety Standard No. 210, *Seat Belt Assembly Anchorages*. You ask whether the specified forces are intended to be 'limit loads' (those loads under which no permanent set, yielding or permanent deformation is allowed) or 'ultimate loads' (those loads under which structural integrity must be maintained even though permanent set, yielding or permanent deformation takes place) (your terms and definitions).; Under the requirements of Standard No. 210, the anchorage of a sea belt assembly must be able to withstand certain designated forces when tested in accordance with the procedures of the standard. Paragraph S4.2.3 of Standard No. 210 provides that permanent deformation or rupture of a seat belt anchorage or it surrounding area is not considered to be a failure, if the required force is sustained for a specified period of time. Therefore, the force requirements of Standard No. 210 could be considered 'ultimate loads,' as you define that term.; The agency interprets the force requirements of Standard No. 207 t allow some deformation of the seats during the force test, provided structural integrity is maintained. Therefore, the force requirements of Standard No. 207 could also be considered 'ultimate loads,' as you define that term.Please note, however, that if seats are displaced to an extent that the agency determines occupant safety is threatened, a determination could be made under provisions of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S 1381, *et seq*.) that the vehicle contains a safety related defect and sanctions could be imposed on the manufacturer.; Please contact our office if you have any further questions. Sincerely, Frank A. Berndt, Acting Chief Counsel