Interpretation ID: nht79-4.2

DATE: 10/30/79

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Wanger Electric Corporation

TITLE: FMVSS INTERPRETATION

TEXT:

NOA-30

Mr. J. W. Kourik Chief Engineer, Brake Products Wagner Electric Corporation 11444 Lackland Road St. Louis, Missouri 63141

Dear Mr. Kourik:

This responds to your September 17, 1979, letter asking whether Standard No. 121, Air Brake Systems, permits manufacturers to install antilock devices on only one axle of a multi-axle vehicle. The answer to your question is yes.

As you know, the decision in PACCAR v. NHTSA, 573 F.2d 632 (9th Cir. 1978); cert. den'd, 439 U.S. 862 (Oct. 2, 1978) invalidated the antilock requirements as they apply to trucks and trailers. Accordingly, the anti-lock provisions of the standard no longer apply to those vehicles. A manufacturer that desires to install anti-lock devices can do so at its own discretion and to any extent that it considers appropriate. This includes the installation of antilock devices on only one axle. Of course, any installation of devices affecting braking must not impair the brake system's compliance with the standard.

Sincerely,

Frank Berndt Chief Counsel

September 17, 1979

National Highway Traffic Safety Administration Office of Chief Counsel Room 5219 Nassif Building Washington, D.C. 20590

Gentlemen:

Wagner agrees with the NHTSA position recognizing the benefits of antilock in their recommendation that antilock systems on existing vehicles be maintained in proper working condition.

In regard to existing and newly manufactured equipment, Wagner is aware that according to Notice 26 of Docket 75-16 dated 8/9/79:

"...the court's remand (9th District Court of Appeals, PACCAR vs. NHTSA and DOT)...precludes the agency from enforcing compliance with any road test requirement for trucks and trailers at any speed on wet or dry surfaces."

And also, as stated in Notice 01 of Docket 79-03 dated 2/15/79:

"...users...may order antilock according to their choice on new vehicles."

Wagner interprets that it is acceptable for manufacturers to equip fewer than all axles of a multi-axle vehicle for antilock control. Therefore, users who do elect to use antilock may choose, for example, a single anti-lock system for only one axle (in lieu of tandem control or axle-by-axle control) on a tandem axle trailer.

Wagner requests confirmation on our interpretation regarding acceptability of installations where fewer than all axles on a vehicle are under antilock control.

Very truly yours,

WAGNER ELECTRIC CORPORATION

J. W. Kourik, Chief Engineer Brake Products

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