Interpretation ID: aiam2496
Manager
Engineering Services
Blue Bird Body Company
P. O. Box 937
Fort Valley
GA;
Dear Mr. Milby: This responds to Blue Bird Body Company's November 2, 1976, request fo confirmation that head and knee contact areas specified under S5.3.1.3 and S5.3.2.2 of Standard No. 222, *School Bus Passenger Seating and Crash Protection*, may be measured by the use of the direct transfer of a medium (such as spray paint) from the head or knee form to the seating surface with the addition of the area that falls within nonintersecting lines that are tangent to the outer bounds of the areas of direct contact. You also request confirmation that the impact requirements of S5.3.1.2, S5.3.1.3, and S5.3.2.2 may be conducted on seating that is attached to a test fixture instead of being mounted in a bus body. In both cases you suggest rulemaking action to make your recommended procedures a part of the standard.; When a standard does not specify a particular aspect of a requirement such as the means to measure contact area, a manufacturer is entitled to use any reasonable method it chooses to demonstrate, in the exercise of due care, that the regulated vehicle or item of equipment in fact conforms to the requirement. For your information, the agency intends to use a contact medium test similar to the test you describe and will include in its computation of 'contact area' the maximum area that falls within nonintersecting line segments that are tangent to the outer bounds of the areas of direct contact. The outer bounds of direct contact do not include areas that represent splattering of the transfer medium without contact of the nead or knee form.; In response to your second request, Standard No. 222 is a vehicl standard. Therefore, the impact requirements have meaning only as they apply to seating when installed in a vehicle. For this reason the agency intends to conduct its compliance testing with the seating installed in a bus. The agency's contemplated procedure may involve the removal of seating around the seating being tested, and the test device may be mounted to the floor in place of the seating that is removed.; However, the requirementk that the seating conform as it is installe does not prohibit a manufacturer from using a different test procedure from that specified, in view of the NHTSA's expressed position on the legal effect of its regulations. To certify compliance, a manufacturer is free to choose any means, in the exercise of due care, to show that a vehicle (or item of equipment) would comply if tested by the NHTSA as specified in the standard. Thus, the NHTSA test procedures need not be duplicated by each manufacturer or compliance test facility. Blue Bird, for example, is free to conduct its test on a test fixture outside the bus as long as it can certify that its vehicle would comply if tested by the NHTSA according to the standard.; In view of this disposition of your requests, the agency does no intend to undertake modification of Standard No. 222 at this time. The NHTSA will continue to monitor the results of tests conducted to determine compliance with the head and kneeform contact area requirements of the standard and will modify the standard if warranted.; Sincerely, Frank A. Berndt, Acting Chief Counsel