Windward Performance Perlan II

Perlan II
Perlan II on display with an Airbus A350 XWB for scale in background
Role	Glider
National origin	United States
Manufacturer	Windward Performance
Designer	Greg Cole
First flight	23 September 2015
Status	Under development
Primary user	Perlan Project
Unit cost	$1.4 to $2 Million U.S.

The Windward Performance Perlan II (English: Pearl) is an American mid-wing, two-seats-in-tandem, pressurized, experimental research glider that was designed by Greg Cole and built by Windward Performance for the Perlan Project.

The aircraft first flew on 23 September 2015 at Redmond Municipal Airport, Oregon.

The Perlan II is a follow-up design to the successful Perlan I and has as its design goal a flight exceeding 90,000 ft (27 km) in altitude. The project's goals include science, engineering and education. The aircraft will be used to study the polar vortex and its influence on global weather patterns. The program also hopes to beat the 85,069 ft altitude record set in 1975 by a SR-71.

The aircraft is made from composites. Its 83.83 ft (25.55 m) span wing has a high aspect ratio of 27:1 and is equipped with airbrakes. The pressurization system produces an 8.5 psi differential, although the two-person crew will wear pressure suits for safety. The landing gear is a retractable monowheel gear. Because the aircraft will operate at extreme altitudes, in only 3% of sea level atmospheric pressure, it will also be flying at true airspeeds in excess of 0.5 Mach. The aircraft was designed to minimize flutter and manage shock wave formation.