Comment power fail? (Score 2) 112
The problem with all these powered lift gizmos (like the Williams X-jet and the Hiller VZ-1) is that you tend to fall out ouf the sky when your engine fails... The Hiller VZ-1 which is also a ducted fan used *two* 30 kW engines, but barely flew out of the ground effect and was limited in speed. More powerful versions had other control problems.