Interpretation ID: 77-4.5

TYPE: INTERPRETATION-NHTSA

DATE: 09/28/77

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: The Coachette Company

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your August 18, 1977, letter asking whether the head protection zone requirements of Standard No. 222, School Bus Passenger Seating and Crash Protection, apply to a portion of your bus located directly above the side windows.

You enclosed a sketch which details the bus sidewall and roof structure. On that sketch, you have shaded a small area asking whether that portion of the bus constitutes part of the bus sidewall or part of the roof structure. The head protection zone requirements of the standard (S5.3.1.1) do not apply to the sidewalls of school buses.

The National Highway Traffic Safety Administration (NHTSA) interprets your sketch to show the sidewall ending and the roof structure beginning at the point where the radius of curvature of the interior structure decreases sharply (see the point marked "A" on the sketch). Since the shaded portion of your sketch falls below that point, it is considered part of the sidewall and need not comply with the head protection zone requirements.

SINCERELY, (Illegible Words)

August 18, 1977

Joseph Levin, Chief Office of Chief Council N.H.T.S.A.

RE: FMVSS 222 Pora. S5.3.1.1.

A clarification of the above referenced standard is urgently needed. Due to the "tumble home" type of the side of some van-type school buses, there is no clear distinction where the side wall would end and the roof structure would start.

S5.3.1.1. of FMVSS 222 states that the head protection zones are the spaces in front of each school bus passenger seat which are not occupied by bus side wall, window or door structure . . . etc.

Please refer to the enclosed sketch and note that the outboard plane (S5.3.1.1. (c)) of the head protection zones intersects the wall at approximately the window header point. The wall extends upward and inward from that point. This leaves an area, indicated by the shaded portion of the sketch that would extend into the head protection zone. Is this configuration in compliance with the standard? There is no greater hazard to the occupant from the window header to well above the upper limits of the head protection (Illegible Word) than any where in the wall area.

It is very urgent that we get an opinion on this just as soon as possible. After you have reviewed this, we would like to phone or if necessary come to your office for the clarification.

Thanking you in advance for your consideration.

E.H. Ryan

ward

SCHOOL BUS MFG., Inc. P.O. BOX 311 HIGHWAY 65 CONWAY, ARKANSAS 72032 DATE - 8-18-77 CHK- DRAFT: DM ENGR: SCALE IN OR OUT PART ORDER NO REV CHANGE BY DATE

MATERIAL -

TOLERANCE

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