MIL-DTL-11891 Track Shoe Sets, Track Shoe Assemblies, Track Shoe Pads And Track Shoe Bushings, Vehicular: ElastomerizedThis specification identifies the requirements for qualification and production control of track systems supporting U.S. Military Tracked Vehicles. This specification is intended primarily for the qualification of elastomeric compounds used in the fabrication of track and track components and to ensure that the quality and performance established at qualification is maintained throughout production. The contractor is held fully responsible for the entire assembly/component including all non-elastomeric components and fasteners.

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MIL-DTL-11891G(AT)

replaced and the contractor receives Government approval (see 3.3). The plans shall reflect the

process parameter controls (see 4.5.1.1) and product characteristic controls (see 4.5.1.2) used to

assure the quality of the end product. The control plans are intended to be dynamic and may be

changed as process improvements are made. The initial plans shall be delivered to the

Government QAR and the Preparing Activity for approval. Any changes to the plans shall be

provided to the Government QAR for concurrence, prior to implementation. The contractor shall

have data available to support any changes to the control plans.

4.5.1.1 Process parameter controls. The quality of the products produced under this

specification shall be controlled through process control techniques, such as statistical process

control (SPC). Process controls shall be of a type that will provide adequate control of the

process. The type and extent of the control is a function of the significance of the parameter

being controlled.

4.5.1.1.1 Process parameter selection. The process parameters selected for control shall

be identified through one of the following process analysis methods: Design of Experiments

(DOE), Regression Analysis, Correlation Studies, Failure Mode Effects Analysis, (FMEA) , or

other formal or scientific process analysis technique. The results of the process analysis shall be

documented. As a minimum, the contractor shall identify how the following parameters are to be

controlled or provide data from the process analysis or other evidence/information that justifies

why one of the following are not controlled: raw material properties, material weights, mixing

and milling conditions (time, temperature, mill banks, etc.) stock lay down temperatures,

extrusion temperatures, booking temperatures, unvulcanized rubber block weights/dimensions,

cleanliness of rubber and metal to be bonded, complete adhesive coverage, injection time, cure

time, mold service time, runner temperature, nozzle temperature, mold temperature, mold

pressure. In addition, the contractor may use any additional parameters to assure production of

acceptable track components. The selected parameters shall be reflected on the control plan(s).

4.5.1.2 Product characteristic controls. Product characteristics are identified in the

technical data package and in this specification. The product characteristics identified shall be

controlled by process control techniques. Adequate process controls are necessary for the

reduction and elimination of these product characteristic inspections as described in 4.5.1 of this

specification.

4.5.1.2.1 Product characteristic selection. As a minimum, the product characteristics to

be controlled or tested are identified in Quality Assurance Provisions, drawings, and this

specification (see 4.5.3 and 4.7). At its own discretion, the contractor may control or inspect any

additional characteristics. However, elimination of the required characteristics shall be supported

by adequate inspection process analysis data. The selected characteristics shall be reflected on the

control plan.