Interpretation ID: nht74-5.16

DATE: 03/01/74

FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA

TO: Mercedes-Benz

COPYEE: C. KACHN; D. PRITCHARD

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of January 21, 1974, which requested interpretation of Federal Motor Vehicle Safety Standard No. 104, "Windshield Wiping and Washing Systems."

The wiped area as stated in S4.1.2, is to be evaluated as a percentage of areas A, B, and C "of the windshield." This means that areas A, B, and C are evaluated in "unwrapped view." rather than in the form of a projection of the Windshield's surface.

SINCERELY,

MERCEDES-BENZ OF NORTH AMERICA, INC.

January 21, 1974

National Highway Traffic Safety Administration Mr. Elwood Driver

Re: Ruling Standard 104

As discussed with Mr. Pritchard on January 18, 1974 Daimler-Benz AG. is seeking a ruling with respect to interpretation of S4.1.2 of paragraph 571.104, windshield wiping and washing systems.

S4.1.2 references in respect of the wiped area to SAE recommended practice J903a from May 1966. Definition of the wiped area on the windshield is outlined in this recommended practice under 2.4 (a), (b), (c) and (d) and constitutes tangential cut-off of the two-dimensional eye range contour.

You are undoubtedly aware that SAE recommended practice J903a has been superseded by SAE J903b, last revised in July 1968. In this practice the wiped area is evaluated in an unwrapped view in which the wiped pattern and the areas A, B and C have been incorporated.

571.104 as well as J903a do not state whether the areas A, B and C should be evaluated in relation to the A area in projected form or in unwrapped view as exercised in J903b.

An early ruling in clarification of the above mentioned problem area is highly appreciated.

G. M. Hespelar Manager Safety Engineering