The professional services market is growing rapidly, according to the recently published report Professional Services Market Global Report 2017 by The Business Research Company. The market is forecast to register a 5.4% growth rate from 2016 to 2020, reaching almost $5 trillion.

Companies are developing aircraft capable of carrying passengers and cargo in urban environments. So what’s keeping them grounded? Several key technological barriers need to be overcome before air taxis take to the skies