http://www.gizmag.com Conventional helicopters are incredibly useful vehicles in many short-range scenarios - but their asymmetrical aerodynamics enforce a fairly low terminal speed limit of around 150mph, making them less than ideal for longer-range missions. Tilt-rotor aircraft like the Falx and Osprey, and coaxial 'copters like the Sikorsky X2 are tackling the problem from different angles, but both result in complicated and expensive solutions - which is what makes the new Challis Heliplane concept quite remarkable. Still in early stages, the Challis uses a very simple design to balance the lift forces of a helicopter and bring top speeds of over 300mph into reach. And wait 'til you see this thing accelerate!en gizmag.com http://www.gizmag.com/challis-heliplane-simple-cheap-and-twice-as-fast-as-a-normal-helicopter/10663/#comment-17737 http://www.gizmag.com/challis-heliplane-simple-cheap-and-twice-as-fast-as-a-normal-helicopter/10663/#comment-17737 Wed, 17 Mar 2010 19:20:46 -0500 http://www.gizmag.com/challis-heliplane-simple-cheap-and-twice-as-fast-as-a-normal-helicopter/10663/#comment-11917 http://www.gizmag.com/challis-heliplane-simple-cheap-and-twice-as-fast-as-a-normal-helicopter/10663/#comment-11917 Tue, 15 Dec 2009 08:43:07 -0600 http://www.gizmag.com/challis-heliplane-simple-cheap-and-twice-as-fast-as-a-normal-helicopter/10663/#comment-424 http://www.gizmag.com/challis-heliplane-simple-cheap-and-twice-as-fast-as-a-normal-helicopter/10663/#comment-424 Wed, 07 Jan 2009 07:28:11 -0600