Interpretation ID: nht79-2.8
DATE: 03/27/79
FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA
TO: Blue Bird Body Company
TITLE: FMVSS INTERPRETATION
TEXT: This responds to your March 1, 1979, letter asking the National Highway Traffic Safety Administration to withdraw an earlier interpretation of Standard No. 222, School Bus Passenger Seating and Crash Protection, which stated that any contactable objects falling within the head protection zone must comply with the head impact and force distribution requirements. The head protection zone might include some areas in the driver's seating location, and therefore, any contactable object in the driver's seating location that falls within the zone must comply with the requirements. The agency declines to alter its interpretation.
The standard is clear in its specification of zones for head form impact and force distribution testing. These zones help to ensure that any contactable objects falling within them will be sufficiently padded to protect a child from serious injury in an accident. The head protection zone for any passenger seat extends into the seat area of the passenger seat immediately in front of it. Similarly, the zone for the front passenger seat might extend into the driver's seating location. You argue that the restraining barrier between the front seat and the driver's seat removes the need for head protection zone requirements in the driver's seating area.
The fact that a restraining barrier separates the driver's seating location from the passenger seat bears no relevance to the need for head impact protection in the head protection zone for the front passenger seat. The head protection zone extends above and beyond the restraining barrier recognizing the possibility that the heads and upper bodies of larger children are likely to be impelled somewhat beyond the barrier in an accident. The barrier should help to prevent a child from being thrown entirely out of its seating position, but a barrier cannot prevent a child's head from being propelled beyond the barrier in some instances. Since the head protection zone requirements are designed to provide protection in these situations and that protection is needed for all passenger seats including the front seat, the agency will not alter its interpretation of the requirements as they apply to the head protection zone for the front passenger seat.
SINCERELY,
BLUE BIRD BODY COMPANY
March 1, 1979
Joseph J. Levin Chief Counsel National Highway Traffic Safety Administration
Reference: 1. FMVSS 222 2. Robert B. Kurre to Frank A. Berndt, April 1, 1977
3. Frank A. Berndt to Robert B. Kurre, N40-30, May 11, 1977
Dear Mr. Levin:
Paragraph S 5.3.1.1 of reference 1 defines a head impact zone relative to the passenger seating reference point which must meet certain performance requirements with respect to head impact testing.
Reference 2 requests a clarification of the zone with respect to the drivers area. Reference 3 states that contactable surfaces in the zone of S 5.3.1.1 must meet the requirements as specified in S 5.3.1.
The purpose of this letter is to question the interpretation given in reference 3.
The driver's side barrier required by S 5.2 effectively isolates passengers from the driver's compartment. To require padded driver's seat frames in addition to isolating them from the passenger compartment is a redundant requirement which adds cost without any corresponding safety benefit.
The only other alternative is to provide more clearance between barrier and the driver's seat. By doing this, driver's seat padding requirements could be avoided. However, since most states have an overall length limit to which specific bus models are designed, this would eliminate at least three passenger positions.
As can be seen from the attached photos, taken before and after a barrier performance test, there is no need to pad the driver's seat since it is isolated from possible passenger impact. The posttest photograph is taken from NHTSA's compliance test report no. 780903 of a Blue Bird All American Schoolbus.
Therefore, on the basis of practicality we would ask that the interpretation given in reference 3 be reversed.
Thank you for your early reply.
W. G. Milby Manager, Engineering Services
Barrier / Driver's Seat relationship, Protest.
(Graphics omitted)
(Graphics omitted)
FIGURE 3-16 (CONT) FORCE/DEFLECTION TEST, DRIVER BARRIER, PRETEST & POSTTEST