Interpretation ID: nht75-3.44

DATE: 09/11/75

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: Lear Siegler, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: I appreciate your letter of August 13, 1975, forwarding a copy of Neway's publication on Standard No. 121, Air Brake Systems. The efforts of companies like Neway to assist final-stage manufacturers in their certification responsibility has been an important part of the implementation of the air brake systems standard.

You asked for review of the booklet, which consists mainly of instructions to manufacturers concerning systems that must be tested and how to establish a basis for certification. This is an area which our statutory scheme leaves to the manufacturer, and in which, aside from discussions of general principles, this agency declined to issue statements of approval. While we appreciate the usefulness of the advice contained in your booklet, we regret that we can not judge the adequacy of a certification program in the abstract.

YOURS TRULY,

LEAR SIEGLER, INC.

NEWAY DIVISION

August 13, 1975

Richard Dyson Assistant Chief Counsel U.S. Department of Transportation National Highway Traffic Safety Adm.

I thought you would be interested in reviewing the enclosed copy of our FMVSS-121 booklet. If you wish additional copies, they are available.

This represents our interpretation of the Safety Standard and our recommendations to the industry in order to guide them in compliance with FMVSS-121.

We would appreciate your critical review of this booklet and any comments that you may have.

Ed Young

LEAR SIEGLER, INC.

NEWAY DIVISION

July 21, 1975

GENTLEMEN: Federal Motor Vehicle Safety Standard No. 121 (FMVSS-121) is a Department of Transportation Safety Standard defining brake system equipment and braking performance to be met by nearly all vehicles with air brake systems. Its purpose is to insure safe braking performance under normal and emergency conditions and is applicable to trucks, tractors, trailers and buses equiped with air brakes. Most trailers manufactured after December 31, 1974, and most trucks, tractors and buses manufactured after March 1, 1975, must meet the requirements of FMVSS-121. FMVSS-121 is in fact a law within which we must abide and conduct our business. Confusing? - complicated? - cumbersome? - Costly? YES! Impossible to deal with and comply? No! Difficult? Maybe at first but it too will come to pass and fall within our experteise and we shall take it in our stride.

FMVSS-121 is to be reckoned with so let us jointly accept it as reality and do everything in our power to comply with the law. Our heavy duty trucking customers are still going to rely on us to supply them with completed, road-ready vehicles, properly certified and meeting all applicable Federal Motor Vehicle Safety Regulations and standards. And it can be done. It is in this spirit that we offer this manual to be used as a guide in installing add-on, non-powered axles to new truck and tractors.

Edward L. J. Young

Director of Engineering