Interpretation ID: nht89-3.32

TYPE: INTERPRETATION-NHTSA

DATE: 11/06/89

FROM: STEPHEN P. WOOD -- NHTSA ACTING CHIEF COUNSEL

TO: S. WATANABE -- MANAGER AUTOMOTIVE LIGHTING ENGINEERING CONTROL DEPT. STANLEY ELECTRIC CO., LTD., JAPAN

TITLE: NONE

TEXT: Dear Mr. Watanabe:

This is in reply to your FAX of September 14, 1989, asking for an interpretation of Motor Vehicle Safety Standard No. 108, with respect to a vehicle headlamp aiming device (VHAD), as shown in the drawing attached to your letter.

You have two questions:

"1) Does a VHAD without a function which compensates the deviation of floor slope satisfy FMVSS No. 108 S7.7.5.2(a)(1)(v)?"

Paragraph S7.7.5.2(a)(v) states that "Means shall be provided in the VHAD for compensating for deviations in floor slope not less than 1.2 degrees from the horizontal that would affect the correct positioning of the headlamp for vertical aim." If a VHAD is "without a function which compensates the deviation of floor slope" it would not satisfy Standard No. 108.

"2) This Head Lamp is designed to be aimed vertically by means of observing only one spirit level placed on the movable reflector, as shown in the drawing. Does this structure of VHAD satisfy FMVSS No. 108 S7.7.5.2(a)(1)(v)?"

The answer is yes, if observation of the simple spirit level is coordinated with an off-vehicle measurement of floor slope. As located, the spirit level with the range of +/- 1.2 degree range will allow aim of the headlamp, even though the vehicle may n ot be level, and will

compensate for floor slopes of up to 1.2 degrees, thus fulfilling the requirement that there be compensatory means when the vehicle upon which the headlamp is mounted is not resting upon level ground.

I hope that this answers your questions.

Sincerely,

[DIAGRAM OF VEHICLE HEADLAMP AIMING DEVICE OMITTED]