In article ,
, Larry Dighera says...

Mentioned in the NASA video at the YouTube link below are the reasons this
revolutionary technology are an exciting step forward for aviation.

* Four horsepower per pound are achievable with electric systems. This is
comparable to turbine engine performance.

* Ninety-five percent efficiency is possible with electric propulsion
systems compared to 45% turbine engine efficiency. This translates into
reduced fuel costs and emissions.

* The technology aims to achieve an 80% reduction in energy requirements.


Notice the rear-facing wing-tip engines on this concept drawing:
http://www.aero-news.net/images/content/aerospace/2015/Airborne-NasaLeapTech-031915.jpg.
Is this a means of overcoming the drag produced by counter rotating wing-tip
vortices inherent in virtually all current aircraft?

I don't think so. Have a look at this...
https://www.youtube.com/watch?v=QKCK...PLCdGBvDMYlr8-
tm7kQibn0iDCBbgpLbX6


--
Duncan.