Interpretation ID: 04-003224drn

Thomas D. Turner, Vice Chairman
School Bus Manufacturers Technical Council
6298 Rock Hill Road
The Plains, VA 20198-1916

Dear Mr. Turner:

This responds to your letter dated April 13, 2004, asking for a technical amendment to correct two errors in Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus emergency exits and window retention and release. We concur that the errors should be corrected.

You ask that the National Highway Traffic Safety Administration (NHTSA) revise the emergency exit window force application requirement at S5.3.3.2 of FMVSS No. 217, which reads in part: "In the case of windows with one release mechanism, the mechanism shall require two force applications to release the exit." You state that aJune 13, 1994, letter from former Acting Chief Counsel John Womack to the Blue Bird Body Company confirmed that the wording of S5.3.3.2 is in need of correction.

You are correct that in the June 1994 letter, the agency determined that the wording is susceptible to being misread as requiring two force applications to open the single release mechanism. In that letter, the agency said that the requirement should have been worded: "In the case of windows with one release mechanism, the exit shall require two force applications to open." (Emphasis added.) In a March 20, 1996, letter to Blue Bird, the agency affirmed the interpretation of the June 13, 1994, letter.

You ask that we proceed with issuing a technical amendment to correct S5.3.3.2. However, you ask that S5.3.3.2 be corrected by adding the words underlined in the following text: "In the case of windows with one release mechanism, the mechanism shall require one or two force applications to release the exit."(You also ask for an identical correction of a roof exit requirement in S5.3.3.3 that is similarly worded: "In the case of roof exits with one release mechanism, the mechanism shall require one or two force applications to release the exit.") Your suggested wording is different than the correction discussed in the previous letters.

Discussion

This letter affirms the position expressed in the agencys June 13, 1994, and March 20, 1996, letters that, under S5.3.3.2, in the case of windows with one release mechanism, the exit shall require two force applications to open. Similarly, under S5.3.3.3, in the case of roof exits with one release mechanism, the exit shall require two force applications to open.

However, we do not agree with your suggested wording. By stating that the mechanism shall require "one or two force applications to release the exit," it permits the mechanism to release (open) the exit upon a single force application. We believe that a single force application is insufficient because, for exits with one release mechanism, there is a potential for ejections through exits if the exit could be opened with just a single force. For example, passengers could be thrown against such a release mechanism in a rollover and accidentally ejected through the opening. (A discussion of NHTSAs concern about ejection through exits with a single action release mechanism can be found in the final rule issuing S5.3.3.2 and S5.3.3.3, 57 FR 49413; November 2, 1992.) Accordingly, the agency continues to interpret S5.3.3.2 and S5.3.3.3 as specifying, for windows and roof exits with one release mechanism, that the exit shall require two force applications to open.

We plan to conduct rulemaking to address this matter as resources permit. If you have any further questions at this time, please contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992.

Sincerely,

Jacqueline Glassman
Chief Counsel

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