Interpretation ID: nht92-8.9

DATE: March 31, 1992

FROM: Tom Mario -- Vice President Sales, Sealco Air Controls, Inc.

TO: Steve Wood -- Office Staff Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 5/21/92 from Paul J. Rice to Tom Mario (A39; Std. 121)

TEXT:

I had recent phone conversation with Mr. Richard Carter about trailer manufacturers using the standard 121 air brake system, "protected separate reservoir", after October 8, 1992.

Mr. Carter said his interpretation is that you could use, "protected separate reservoir" or 49 CFR part 571 (Docket No. 90-3; Notice 2).

Also requesting your interpretation, for full trailer, rear axles with new system (Docket No. 90-3; Notice 2) which air brake system is required for front axle (turntable) with service brake chambers?

Also multiple axle trailers, with new system (Docket No. 90-3; Notice 2) on some axles and other axles with service chambers, which air brake system is required?