Air

The S-97 Raider coaxial helicopter made by Lockheed Martin Corp.'s Sikorsky unit recently flew with its wheels up for the first time. (Image via video courtesy Lockheed Martin)

WATCH: S-97 Raider Flies with Wheels Up

The S-97 Raider coaxial helicopter made by Lockheed Martin Corp.’s Sikorsky unit recently flew with its wheels up for the first time. The company has…