The Fire Propagation apparatus (FPA) is an extremely powerful flammability test applicable to a wide range of materials. The material can be tested in a broad range of heating conditions in a controlled, customizable gaseous environment. Perhaps, the main drawback of the FPA is its complex design, which makes it difficult to manufacture and maintain. In this work, the main parts of the FPA, including the frame structure, combustion air distribution chamber, water cooled outer shield, load cell, and sample support assembly were redesigned and built to improve manufacturability, maintainability, and ease end user operations. It also demonstrated that the new design produces higher resolution sample mass evolution measurements than the original design. A comparative study between the FPA, Cone Calorimeter, and Controlled Atmosphere Pyrolysis Apparatus II was conducted at both flaming and non-flaming conditions using poly(methyl methacrylate). Some systematic differences in the performance of these material flammability test methods were observed, which require further investigation.