| |
Helicopter Encyclopedia Article, Information, History and Biography @ LaunchBase.org (Site not responding. Last check: 2007-10-19) |
 | | The availability of lightweight turboshaft engines in the second half of the 20th century led to the development of larger, faster, and higher performance helicopters. |
 | | Turboshaft engines are the preferred powerplant for all but the smallest and least expensive helicopters today. |
 | | In conventional aircraft, the wing profile (called airfoil) is designed to deflect air efficiently downward. |
| www.launchbase.org /encyclopedia/Helicopter (4847 words) |