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Interpretation ID: 21971.ztv



    Mr. Thomas J. Carter, P.E.
    Carter Engineering
    5735 North Lick Creek Road
    Franklin, TN 37064



    Dear Mr. Carter:

    This is in reply to your fax of August 3, 2000, asking for a clarification of whether headlamp aiming mechanisms are required for motorcycles, and, if so, where they are specified in Motor Vehicle Safety Standard No. 108.

    You reference our letter of December 6, 1999, to Sig. Rotta of Piaggio in which we informed him that we did not intend S7.8.2 of Standard No. 108 to apply to motorcycle headlighting systems, and that we have never required these systems to have aiming mechanisms. You believe that this opinion is contradicted by SAE Recommended Practice J566, "Headlamp Mountings," January 1960, incorporated by reference in Table III of Standard No. 108.

    I confirm my earlier statement that Standard No. 108 has never required motorcycle headlighting systems to have aiming mechanisms. SAE J566 requires that headlamps and headlamp mountings be designed and constructed so that:

      "1.   The axis of the light beams may be adjusted to the left, right, up, or down from the designed setting, the amount of adjustability to be determined by practical operating conditions and the type of equipment.

      2.   The adjustments may be conveniently made by one man with the tools ordinarily available.

      3.   When the headlamps are actuated, the aim will not be disturbed under ordinary conditions of service."

    As S5.2.1 states, the words "it is recommended that" and "recommendations" or "should be" in SAE Standards and Recommended Practices are read as setting mandatory requirements. Although the word "may" used in SAE J566 is not included in this list, we intend that it be read as a mandate as well. Applying this construction to SAE J566, then, Standard No. 108 requires light beams on all headlamps to be adjustable with the tools ordinarily available, but in no way do I interpret this as imposing a requirement for an "aiming mechanism." The aiming mechanism requirements of Standard No. 108 are imposed by S7.8, and, as I indicated previously, we do not intend S7.8.2 to apply to motorcycle headlamps. We intend the paragraphs of S7.9 Motorcycles and their referenced materials to cover motorcycle headlamps. These do not require motorcycle headlamps to have aiming mechanisms as defined elsewhere in Standard No. 108.

    If you have any questions, you may contact Taylor Vinson of this Office (202-366-5263).

    Sincerely,

    Frank Seales, Jr.
    Chief Counsel

    ref:108
    d.9/29/00