tag:blogger.com,1999:blog-5958379051419336630.post4285960759104569705..comments2023-03-21T19:50:48.243-07:00Comments on Civilian Plane Spotters: 250 Miles-Per-Hour: The Top Speed Of The Conventional Helicopter?Ringohttp://www.blogger.com/profile/09506068154852505840noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-5958379051419336630.post-83135874185406243762015-11-30T05:55:31.311-08:002015-11-30T05:55:31.311-08:00In 1972, helicopter aerodynamicist Peter G. Wilby ...In 1972, helicopter aerodynamicist Peter G. Wilby transformed the helicopter rotor to become more aerodynamic by slightly sweeping back the rotor tips and by making the helicopter's main rotor cross section vary over its length. It took 13 years of tests after 1972 to change the helicopter rotor design from traditional rectangular blades to the newfangled swept back tipped blades. This resulted in a faster forward speed and greater lift capability which made helicopters fly ever closer to their "theoretical" speed limit of 300 miles-per-hour. Then, man-made composites that were developed during the latter half of the 1980s only benefited helicopter designers and manufacturers without end. Digital avionics advances made during the 1990s allowed the creation of "fly-by-wire" / "hover autopilot" for helicopters that made them easier to allow to perform rescue operations with relative ease. Marie Lynnehttps://www.blogger.com/profile/04665034029611645050noreply@blogger.comtag:blogger.com,1999:blog-5958379051419336630.post-57431476453308418422015-05-29T06:48:23.580-07:002015-05-29T06:48:23.580-07:00Thanks to BERP - the British Experimental Rotor Pr...Thanks to BERP - the British Experimental Rotor Programme - led by Peter Wilby and Geoff Byham that bresulted in the "sewpt-back" rotor tip, the Westland Lynx managed to achieve the helicopter top world's speed record back in August 11, 1986 by reaching 250 miles per hour or 400 kilometers per hour in level flight, a record that stood until this very day. Wilby and Byham's "modified" Westland Lynx had a lift-to-drag ratio of 2 at 400 kilometers per hour while at that speed - their BERP rotor achieve a rotor tip speed of Mach 0.97, any faster and the lifting efficiency of that rotor stays constant despite of additional rotational shaft horsepower. Michellehttps://www.blogger.com/profile/07762766021860517042noreply@blogger.com