Interpretation ID: 19040.ztv

Mr. Siegfried Hetz
Senior Optic Engineer
Robert Bosch Corporation
38000 Hills Tech Drive
Farmington Hills, MI 48331-3417

Dear Mr. Hetz:

This is in reply to your fax of November 4, 1998, asking for an interpretation of the vehicle headlamp aiming device (VHAD) requirements of Federal Motor Vehicle Safety Standard No. 108. You have enclosed several engineering drawings for our review and asked whether "the design passes NHTSA's requirements to be permanently fixed (tamper-proofed)." Later, by letter of November 13, 1998, you provided Taylor Vinson of this Office with a sample of a mockup of the proposed VHAD.

The requirement that concerns you is S7.8.5.2(c) of Standard No. 108. This requires each headlamp with a VHAD to be manufactured with its calibration permanently fixed by the headlamp manufacturer. We have examined your drawings and the VHAD. The principal feature is a "wedge block [which] will lock into the V-HAD plate while also locking the V-HAD legs down in position." One of our engineers was able to remove the wedge block with a letter opener, after some minutes, and after consulting your drawing with its sectional view depicting the wedge block. However, we have decided that the calibration of the VHAD is "permanently fixed" as required by S7.8.5.2(c). It is our opinion that a person interested in removing the wedge block would have to remove the headlamp to do so, but, in the absence of access to your engineering drawing with its sectional view, would be unlikely to be able to proceed further and remove the wedge block.

Please let Mr. Vinson know if you wish the mockup returned (202-366-5263).

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:108
d.12/28/98