Interpretation ID: nht68-1.21

DATE: 04/26/68

FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA

TO: Blue Bird Body Company

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of March 19, 1968, to Mr. George C. Nield, requesting a clarification of paragraphs S3.4.4 and S3.4.4.1 of Motor Vehicle Safety Standard No. 108.

In your letter you listed possible brake combinations as follows:

1. A vacuum over dual hydraulic brake system and a hand operated mechanical brake are provided.

2. A full air brake system and a hand operated mechanical brake are provided.

3. A full air brake system with a spring loaded emergency stopping system which is actuated at a pre-determined low air pressure level and a hand operated mechanical brake are provided.

In accordance with the interpretation issued February 27, 1967 (32 F.R. 3390, copy enclosed), on "emergency brakes," the supplementary brake systems included in the above brake combinations are not emergency brakes. Therefore, paragraph S3.4.4 of Standard No. 108 does not require that the stop lamp be actuated upon application of these supplementary brakes.

Thank you for writing.