McDonnell XH-20 Little Henry

The McDonnell XH-20 Little Henry is a 1940s American experimental lightweight helicopter designed and built by McDonnell Aircraft. == Development == The McDonnell Model 38 was a lightweight experimental helicopter sponsored by the United States Army Air Force to test the concept of using small ramjets at the tips of the rotor blades.

Source: Wikipedia — McDonnell XH-20 Little Henry (CC BY-SA 4.0)