Israel has had this one for a while looks pretty conventional without the monster props and gear boxes that are being discussed. 16000 ft plus. Easily hand launched. Looks to use a standard Graupner Cam Prop
http://www.israeli-weapons.com/weapo...k/Skylark.html

Fine tuning your prop with 3.5 and 5 degree twisted yoke spinner.

http://www.hyperflight.co.uk/product...ead-this-first

The Tigershark UAV twin boom pusher UAV

FAA would have to authorize high-altitude test flights
By GCN Staff
Jul 13, 2011
Oklahoma officials and business leaders business are looking to make the state a center of activity for unmanned aerial vehicles.
They want to designate a strip of airspace between Fort Sill and the Clinton-Sherman Airport as a test zone for UAVs in which commercial developers could routinely fly UAVs at high altitudes, reports Steve Metzer at the Lawton Constitution.
The agreement in the making would build on efforts begun in 2006 when the Oklahoma State University Multispectral Laboratory (UML) worked with the Defense Department to locate a UAV-dedicated airport at Lawton-Fort Sill where the lab has an existing agreement with the Army to fly UAVs over part of Fort Sill up to an altitude of 40,000 feet — something not allowed in civil airspace.
A request has been sent to the Federal Aviation Administration for a certificate of authorization allowing flights of a UAV called a TigerShark in and out of the Clinton-Sherman Airport and, if that’s granted, a second certificate would be applied for to allow flights of TigerSharks between Clinton-Sherman and Lawton-Fort Sill, Stephen McKeever, the state’s secretary of science and technology and also the executive director of the UML, told the Lawton Constitution.

From this site http://www.pathfindersystems.com/techpub/haleuav.htm

A Practical Design of High Propulsive Efficiency