Indian security forces are nervous about the possibility of terror attacks using paragliders or drones, according to sources quoted by IBN Live . But Francesco's insists the experiment was safe. A source told the Economic Times the drone never went higher than 130m (400ft) to avoid interfering with other traffic, and the craft was never out of the reach of the controller. Last year, Amazon said it was testing unmanned drones for deliveries, but said it could take up to five years for the service to actually start.