GREAT (German REceiver for Astronomy at Terahertz frequencies) has been selected as first-light instrument for the early science flights of SOFIA, scheduled for early 2009. In its first-light configuration GREAT will allow observations in two out of three FIR bands: two low frequency channels 1.25-1.5 THz and 1.82-1.92 THz for observations of, e.g., highly excited CO and of ionized carbon, and a 2.7 THz channel focusing on the ground-state transition of deuterated molecular hydrogen HD. A forth channel, centered on the 4.7 THz transition of atomic oxygen will become available later. The observatory schedule asks for delivery of the instrument in early 2009. At the time of the conference system level assembly, integration, and verification (AIV) is ongoing, and we report on the performance of the integrated system. Shipment to NASA/DAOF (Dryden aircraft operations facility) in Palmdale/California for aircraft integration is currently planned for mid December 2008.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.