A Sikorsky YR-4B/HNS-1 sits in a wind tunnel as a technician sets up camera equipment to take stop-action photos of the rotors. The R-4 was the first helicopter to be built in any significant number--several hundred were constructed during World War II.
The essence of this design, like that of PV-2 from Piasecki--a large main rotor and a small vertical tail rotor (just one of each)--has been the guiding force for most modern helicopters. Much of the credit for that design, and for turning helicopters into a practical reality, goes to Igor Sikorsky, a Russian immigrant to the U.S.
Talkback
More ZDNet Photo Galleries
-
- Visit the ZDNet Enterprise Mobility Hub sponsored by Verizon Wireless! It has the latest news, commentary, and resources for your mobile and wireless strategy development.
- Video: How to spoof a MAC address
- Five steps to protect mobile devices anywhere, anytime
- Fetch Your E-Mail from Anywhere
- From our sponsors
-
- Push to Talk from Verizon Wireless Choose Verizon Wireless and get a Push to Talk service you can rely on. The only service that comes with the Network. Starting at $699.
-
