Interpretation ID: 86-1.40

TYPE: INTERPRETATION-NHTSA

DATE: 02/21/86

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: Dean Hansell, Esq.

TITLE: FMVSS INTERPRETATION

TEXT:

Dean Hansell, Esq. Messrs. Donovan Leisure Newton & Irvine 555 South Flower Street Los Angeles. California 90071

Dear Mr. Hansell:

This is in reply to your letter of January 14, 1986, asking whether Federal Motor Vehicle Safety Standard No. 108 permits headlamps to be nonrectangular.

Standard No. 108 prescribes dimensions only for sealed beam headlamps, in accordance with the terms of the standard and the materials of the Society of Automotive Engineers incorporated by reference. Under these requirements, sealed beam headlamps must be either circular or rectangular according to either the diameters or length/width dimensions specified.

In 1983 Standard No. 108 was amended to allow additional headlighting systems (see paragraph 54.1.1.36) incorporating a replaceable light source with an "0" ring seal. Dimensions are prescribed for this light source. With this type of system, the emphasis on standardization of lighting equipment shifts from size and shape of the unit to the light source itself. This allows the headlamp designer freedom to choose the headlamp size and shape most acceptable to his client within the constraints of the standardized replaceable light source and the photometric requirements of the standard which are essentially the same for all headlamps. Further, such headlamps must be capable of mechanical aim just like sealed beam units.

I hope that this answers your question.

Sincerely,

Erika Z. Jones Chief Counsel

January 14, 1986

Erika Z. Jones, Esq. Chief Counsel National Highway Traffic Safety Administration 4000 Seventh Street, S.W. Room 5219 Washington, D.C. 20590

Re: FMVSS 108 - Request for Interpretation

Dear Ms. Jones:

We seek the Agency's interpretation concerning FMVSS 108 (Lamps, Reflective Devices, and Associated Equipment). Our question is whether headlamps can be nonrectangular.

We find nothing in FMVSS 108 mandating a specific shape for a headlamp. However, the illustrations in FMVSS 108 (for example, figures 11 and 12) all show rectangular headlamps. Although this is presumably due to the fact that only rectangular headlamps were available at the time the regulations were initially written, it did raise a question whether some intention to limit the shape of headlamps was being indicated. In any case, it is now our understanding that in connection with the rewriting of FMVSS 108, the size and shape of headlamps has been "deregulated".

We do understand that, if an alternate shaped headlamp is used, the beam pattern and photometric output specifications of FMVSS 108 must be followed and the headlamp must be capable of being used with a standardized universal adapter (or have an "O" ring).

Thank you for your assistance on this matter.

Yours truly,

Dean Hansell

DH:l

cc: Jere Medlin Crash Avoidance Division