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Interpretation ID: aiam1537

Mr. J. W. Lawrence, Truck Group, White Motor Corporation, P.O. Box 91555, Cleveland, OH 44101; Mr. J. W. Lawrence
Truck Group
White Motor Corporation
P.O. Box 91555
Cleveland
OH 44101;

Dear Mr. Lawrence: This responds to your recent request for an interpretation of S5.3.1. of Standard No. 121, *Air brake systems*. That section permits certain vehicles to avoid the stopping distance requirement if their brakes conform to a retardation formula and values found in another section of the standard (S5.4.1).; The language of S5.3.1.2 makes clear that any truck in the describe category need not meet the stopping distance requirements if its brakes satisfy the retardation formula and values of S5.4.1, and therefore none of the exceptions found in S5.4.1 apply to vehicles subject to the requirements of S5.3.1.2.; This interpretation also appears in the preamble to Notice 2 of Docke No. 73-10, and is enclosed for your information.; Yours truly, Richard B. Dyson, Assistant Chief Counsel