The Stearwing D45 is a stock craft that uses the Spaceplane Plus added into KSP 0.25. Like the Aeris 4A, it is a spaceplane capable of reaching Kerbin orbit, but in contradistinction with Aeris, the Stearwing is not SSTO due to decoupling its jet engines. It is the only forward-swept wing example craft. It seems like Stearwing D45 has a problem with the alignment of center of lift and center of mass when all the fuel are drained.
|“|| The Stearwing D45 features a unique two-stage design: The first stage takes it up to the edge of the atmosphere and nearly to orbital speed. The second stage kicks in just as the turbines start to flame out, and twin LV 909 rockets take it from there out to space. The D45 carries a crew of 2 plus 4 passengers in a pressurized cabin, as well as up to 6 more in its cargo bay seats. Vernor thrusters are located in the bay and aft sections. Press 1 (twice) to disable them before takeoff.