Interpretation ID: nht93-4.14

DATE: June 2, 1993

FROM: John Womack -- Acting Chief Counsel, U.S. Department of Transportation, NHTSA

TO: Vincent Schulze -- Chief, Motor Carrier Inspection and Investigation, State of New Jersey, Department of Transportation

TITLE: None

ATTACHMT: Attached to letter dated 2-26-93 from Vincent Schulze to Ron Havelar.

TEXT: This responds to your February 26, 1993 letter to Mr. Ron Havelar of the Federal Highway Administration. Because your question concerns a safety standard issued by the National Highway Traffic Safety Administration (NHTSA), it has been referred to my office for reply. You ask whether a bus can comply with the requirements of Standard No. 217, BUS WINDOW RETENTION AND RELEASE, particularly S5.4, if it is equipped with side exit windows which slide open.

NHTSA's longstanding position is that sliding windows are not prohibited by Standard No. 217, as long as they comply with all of the standard's requirements. The requirement in S5.4 that the emergency exit must be "manually extendable" refers to the ability to open the exit manually, i.e., even when the bus's power is off. Sliding windows must also be capable of complying when the window is in either the opened or the closed position.

While sliding windows are not prohibited, NHTSA believes it is difficult for sliding windows to comply with the requirements of Standard No. 217. For example, S5.3 of Standard No. 217 specifies release requirements for emergency exits. Section S5.3.2 states, in part,

The release mechanism or mechanisms shall require for release one or two force applications, at least one of which differs by a 90 degrees to 180 degrees from the direction of the initial push-out motion of the emergency exit (outward and perpendicular to the exit surface).

Thus it appears that the initial motion to open an exit window must be outward and perpendicular to the exit surface, even if it is a sliding window.

You should be aware that on February 25, 1992, the Blue Bird Body Company petitioned the agency to amend Standard No. 217. One issue raised by this petition is the installation of sliding exit windows. This petition has been granted and the agency is proceeding with rulemaking on this issue.

I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992.