Interpretation ID: aiam1489
Purchasing Manager
Weyerhaeuser Company
Tacoma
WA 98401;
Dear Mr. Holen: This responds to your April 29, 1974, request to be apprised of th Standard No. 121 requirements concerning air brakes on trucks and trailers.; Standard No. 121, like all Federal motor vehicle safety standards, is manufacturer requirement, not a user requirement. While it places obligations on the vehicle manufacturers to construct their vehicles so that they conform to the standard, it does not place any responsibilities on you as a user of air brake-equipped vehicles.; If you would nevertheless like to examine the current requirements they may be obtained from the Government Printing Office as explained in the enclosed brochure, or from commercial or library sources as part of Chapter V of Title 49 of the Code of Federal Regulations.; Yours truly, Richard B. Dyson, Assistant Chief Counsel