To counter a fishtail issue Virgin Galactic’s twin fuselage carrier aircraft WhiteKnightTwo (WK2) is suspected to have, vortex generators are pictured here added to its vertical stabilisers prior to its second flight. Taking off from Mojave air and spaceport’s runway 30 on 5 February the WK2 returned to testing with a 1.5h flight with a Beech Starship chase plane. The aircraft did a low pass and then a touch-and-go before finally touching down. This second flight took place about seven weeks after its maiden flight on 21 December 2008. To see a very close up image of the vortex generators location on the vertical stabilisers and an explanatory text description go to this Hyperbola blog post

WhiteKnightTwo vortex generators
 © Alan Radecki

Source: Flight International