Interpretation ID: aiam2510
Manager
Engineering Services
Blue Bird Body Company
P. O. Box 937
Fort Valley
GA 31030;
Dear Mr. Milby: This responds to your December 20, 1976, request for confirmation tha the National Highway Traffic Safety Administration (NHTSA) intends to test the leg protection zone in Standard No. 222, *School Bus Passenger Seating and Crash Protection*, in such a manner as to ensure that the entire knee form will contact with the seat back or restraining barrier and will not extend beyond them.; The knee form contact area measurement required by Standard No. 222 wa intended to measure the distribution of forces over an adequate area of the knee in an impact situation. The measurement is meaningful, therefore, only when the contact area is tested in a manner that provides opportunity for the knee form to contact with the seat back or restraining barrier to the fullest extent possible. In accordance with the intent of the standard the agency will not test the contact area in any configuration where the hemispherical surface of the knee form testing device extends beyond the test surface.; Sincerely, Frank A. Berndt, Acting Chief Counsel