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Safety Recommendation Details

Safety Recommendation H-97-037
Details
Synopsis: About 3:25 p.m. a 1988 Mack truck with a concrete mixer body was unable to stop as it approached a "t" intersection at the bottom of an exit ramp in Plymouth Meeting, Pennsylvania. As the truck proceeded through the intersection, it collided with and overrode a 1985 Subaru passenger car. The Subaru driver was killed; the truckdriver sustained minor injuries. The truckdriver was unrestrained; the Subaru driver was found restrained in her vehicle. The weather was clear and dry. No fire ensued, and no other vehicle occupants were involved in the accident.
Recommendation: TO THE TRUCK MANUFACTURERS ASSOCIATION: Notify your membership of the circumstances of this accident and urge them to install, on all the commercial trucks they manufacture with dual air brake systems, separate low-air-pressure warning devices that will independently alert operators to a loss of air pressure in either system.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Highway
Location: Plymouth Meeting, PA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: NRH96FH009
Accident Reports: Truck Loss of Braking Contol on Steep Downgrade and Collision with a Vehicle
Report #: HAR-97-02-SUM
Accident Date: 4/25/1996
Issue Date: 10/29/1997
Date Closed: 7/17/2009
Addressee(s) and Addressee Status: Truck Manufacturers Association (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: Truck Manufacturers Association
Date: 7/17/2009
Response: The NTSB notes that the TMA’s membership has taken action to ensure that air-braked trucks with a dual air system are equipped with dual low-air-pressure switches that activate in-cab lights and/or buzzers and in-cab air pressure gauge indicators for both the primary and secondary air systems. Such a configuration gives drivers two means of determining whether the primary and secondary systems are charged with sufficient air. The NTSB further notes that TMA members reviewed their brake maintenance service and repair manuals and included instructions and maintenance test procedures for checking and determining that, after air brake system repairs are completed, air lines are properly connected to their intended primary/secondary circuit and that the low air warning pressure switch and air gauge for that circuit function as intended. These actions satisfy the intent of Safety Recommendation H-97-37; accordingly, the recommendation is classified CLOSED—ACCEPTABLE ACTION.

From: Truck Manufacturers Association
To: NTSB
Date: 7/25/2008
Response: Letter Mail Controlled 8/20/2008 3:23:16 PM MC# 2080498: All air-braked trucks have a dual air system that is equipped with dual low-air-pressure switches that activate in-cab lights and/or buzzers. These vehicles are also equipped with in-cab air pressure gauge indicators for both the primary and secondary air systems. Thus, drivers have two ways of determining whether the primary and secondary systems are charged with sufficient air. In addition, TMA members reviewed their brake maintenance service and repair manuals and included instructions and maintenance test procedures for checking and determining that, after air brake systems repairs are completed, air lines are properly connected to their intended primary/secondary circuit, and that the low air warning pressure switch and air gauge for that circuit functions as intended. We trust that these responsive actions taken by TMA’s members will enable the Board to close this Recommendation with an Acceptable designation.