he overall goal of the programme is to build a demonstrator aircraft and fly it in the fourth quarter of 2017. The programme is expected to last a total of 52 months and cost USD130 million. The agency expects to see a test flight in 42 months
According to DARPA, this will be no easy feat, since the history of VTOL aircraft is littered with attempts to achieve top speeds without adversely affecting the aircraft's lift.
