Plane & Pilot
Tuesday, February 25, 2014

The Perlan Project

A former test pilot and a group of engineers are hoping to take a pressurized glider to FL900

For that very reason, the Perlan II will need to maintain about Mach .50 to avoid a stall. Vne will be 377 knots true airspeed (about 56 knots indicated). The Perlan II will need to be extremely clean aerodynamically since there's so little atmosphere at FL900, any drag will be a major disadvantage.

Windward Design of Bend, Ore., is working diligently on the Perlan II, and the aircraft will be built hell for stout, with stress limits of +6 and -4 Gs, only appropriate considering it will need to fly in a region where little is known about turbulence. Remember, this will be an aircraft without an engine, so lift will only be provided by thermal or mountain wave activity.
Finding a good thermal can be a problem...staying in it is an additional challenge.
After Fossett's death in 2007, funding slowed dramatically. Enevoldson's team nevertheless continues work on the Perlan II, designed specifically for a trip to 90,000 feet MSL in semi-pressurized comfort. So far, they've spent $2.8 million on the project, and Enevoldson hopes to launch the record flight by 2015.

The former test pilot has good reason to believe the flight is possible, partially because of a combination of the southern jet stream and the South Polar vortex that circles the Earth at certain times of the year, 60-70 degrees south of the equator.

If Enevoldson is successful, the Perlan II will be used to study the polar vortex and its influence on global weather patterns. Enevoldson also hopes to be able to take a variety of atmospheric measurements of various gases present in the Ozone hole at extreme altitude.

Enevoldson suggests the aircraft could be used for a variety of other research projects in the 90,000 to 100,000-foot range of the stratosphere.

And remember, that's without an engine.


Add Comment