Interpretation ID: nht95-3.71

TYPE: INTERPRETATION-NHTSA

DATE: August 4, 1995

FROM: John Womack -- Acting Chief Counsel; NHTSA

TO: Jane L. Dawson -- Specifications Engineer; Thomas Built Buses, Inc.

TITLE: NONE

ATTACHMT: ATTACHED TO 5/18/95 LETTER FROM JANE DAWSON TO WALTER MYERS

TEXT: Dear Ms. Dawson:

This responds to your letter to Walter Myers of this office regarding the May 9, 1995, amendment of Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus Window Retention and Release. I apologize for the delay in responding. For your future referen ce, Mr. Myers is no longer assigned to our school bus standards. You may address requests for interpretation directly to me.

The May 9 amendment (60 FR 24562) to FMVSS No. 217 permitted, among other things, bus manufacturers to meet the additional emergency exit area (AEEA) requirements of S5.2 by permitting manufacturers to install two emergency exit windows as an alternative to an emergency exit door. You asked what the location requirements (fore and aft) are for the emergency windows that are used as the first additional emergency exit.

FMVSS No. 217 contains no explicit fore and aft location requirements for the two additional emergency exit windows. However, the intent of the final rule was to substitute the location requirements of the side exit door when the windows are used to sat isfy the requirement for the first additional emergency exit. This intention is reflected in the use of the conjunctive word "or" in Tables 1 and 2 of the May 9, 1995, amendment. If a left side exit door would have been installed pursuant to S5.2.3.1(a )(2)(i), then S5.2.3.2(a)(2) requires that it be located as near as practicable to the midpoint of the passenger compartment. The same fore-aft location should be used for the windows. In cases where the fore-aft location is not specified, such as a ri ght side exit door installed pursuant to S5.2.3.1(b)(2)(i), then the windows should be placed so as to provide bus passengers with maximum accessibility to an emergency exit, in accordance with what is reasonable and practicable.

Also note the explicit location requirement in S5.2.3.2(c) that exit windows be evenly divided between the left and right sides of the bus. For example, if two exit windows are used instead of a left side exit door, they should be placed on opposite sid es at the midpoint of the bus.

I hope this information will be of assistance to you. Should you have any further questions or seek additional information, please feel free to contact Paul Atelsek at this address or by calling (202) 366-2992.