Interpretation ID: aiam1122
Rockwell-Standard Division
Automotive Technical Center
2445 West Maple Road
Troy
MI 48084;
Dear Mr. Rodger: By letter of January 31, 1973, Rockwell- Standard requested th National Highway Traffic Safety Administration to postpone the effective date of Motor Vehicle Safety Standard No. 121, *Air Brake Systems*, for twenty-four months with respect to vehicles having front axles with GAWR's of more than 12,000 pounds, single rear axles with GAWR's of more than 23,000 pounds, or tandem rear axles with combined GAWR's of more than 50,000 pounds.; After considering the request, which asks relief from all provisions o the standard, the agency has concluded that an exception of such magnitude is not warranted and therefore denies the request. The agency makes no finding as to whether more limited relief may be appropriate, and does not consider the denial of the January 31 request to preclude the company from submitting petitions for relief from specific aspects of the standard.; Sincerely, James E. Wilson, Associate Administrator, Traffic Safet Programs;