Interpretation ID: nht78-2.5

DATE: 11/28/78

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

TO: Blue Bird Body Company

TITLE: FMVSS INTERPRETATION

TEXT:

NOV 28 1978

NOA-30

Mr. W. G. Milby Manager, Engineering Service Blue Bird Body Company P.O. Box 937 Fort Valley, Georgia 31030

Dear Mr. Milby:

This responds to your August 3, 1978, letter asking how to compute the area of a sample of a body panel when testing for compliance with Standard No. 221, School Bus Body Joint Strength.

In your letter, you suggest that the net cross-sectional area of the sample is determined by multiplying the width of the sample by its thickness and then subtracting the area of each discreet fastener hole. The National Highway Traffic Safety Administration agrees that this procedure yields the correct area of the sample, and is the method used by the agency in its compliance testing.

Sincerely,

Joseph J. Levin, Jr. Chief Counsel

August 3, 1978

Mr. Joseph J. Levin Chief Counsel National Highway Traffic Safety Administration Washington, D.C. 20590

Dear Mr. Levin:

The purpose of this letter is to seek confirmation of our interpretation regarding FMVSS 221, School Bus Joint Strength.

It is our understanding that in meeting the requirements of S5, that the area to be used for calculating purposes, when discreet fasteners are used, is the net area of the weakest joined body panel. We define the net area as the width of the sample multiplied by its thickness, less the projected area of each discreet fastener hole.

We look forward to receiving an early written confirmation of this interpretation.

Thank you.

Very truly yours,

W. G. Milby Manager, Engineering Services

sw