The air separation market for large air compressor trains is continuously growing, driven by future oriented applications like gastoliquid or coaltochemicals. We have recently introduced the AIRMAX train for large air separation units (ASU). As main air compressor it features our proven and now further developed axial/radial main air compressor type AR, now called ARMAX1. In its new blading, ARMAX1 combines for the first time the advantages of both heavyduty as well as aircraft engine compressors. This makes ARMAX1 uniquely compact, as well as robust and efficient.