Flying cars remain science fiction as 24 teams fail to claim $1m prize

With a forceful buzz, Pete Bitar's home-made personal aircraft takes to the skies above Silicon Valley, his aluminium pilot chair glinting in the morning sunlight above four spinning propellers. Dubbed the Verticycle, it wobbles to a height of about three metres before tipping sideways and plunging back to the runway with a loud crash. Fortunately, Bitar is piloting the vehicle remotely today from a wireless controller nearby. The craft's battery packs were damaged in another crash the week before, and replacements couldn't generate enough thrust to lift him and the …