Interpretation ID: nht75-4.41

DATE: 10/01/75

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: United States Testing Co., Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of September 11, 1975, in which you asked whether Standard No. 217 requires a minimum retention or force in pushing out an emergency exit window after activation of the release mechanism.

You should note that the force applications specified in S5.3.2 for operation of the release mechanism and subsequent extension of the exit by an occupant are maximum requirements. Therefore, a push-out window which only requires enough force to lift the glass and subframe following operation of the release mechanism complies with the requirements of S5.3.2 and S5.4 as long as that force does not exceed the levels specified for the particular reach distance of the release mechanism.

The standard specifies no minimum force requirements for either the operation of the release mechanism or the extension of the exit following release.

SINCERELY,

September 11, 1975

Frank A. Berndt Acting Chief Counsel, Department of Transportation

I am writing on behalf of one of our commercial clients, who has requested a legal interpretation of one point of Federal Motor Vehicle Safety Standard No. 217, "Bus Window Retention and Release" (49 CFR 571.217).

The point in question pertains to paragraph S5.3.2 where a maximum force is quoted for window push out after the emergency release mechanism has been actuated. Our client has designed a side window system where, after the emergency release mechanism is activated, only hinges at the window top retain the window. Thus, no push-out force is required other than that to overcome the weight of the glass and sub-frame. The question of interpretation arises as to whether some form of retention is required at the bottom of the window after actuation or if a minimum push-out force at the proper access region applies.

I trust that the above information satisfactorily describes our problem and anxiously await your reply.

Thank you in advance for your cooperation in this matter.

UNITED STATES TESTING COMPANY, INC.

John Lomash Product Engineering Sales