The Challenger 605 was introduced in 2005 at the NBAA convention in Orlando, FL. It is similar to the CL604 but features the Rockwell Collins Pro Line 21 avionics suite and a redesigned cabin.
The Challenger 604 has been the fastest selling model of the Challenger series of aircraft, to date. It is powered by GE CF34-3B engines, with 3 percent lower fuel consumption, than 601-3A engines. The 604 has a maximum range of 4,000 nautical miles.
The Challenger 605 made its first flight on January 22, 2006.