Schreder HP-20

From Wikipedia, the free encyclopedia
Jump to: navigation, search
HP-20
Role Glider
National origin United States
Designer Richard Schreder
First flight 1981
Introduction 1981
Number built one

The Schreder HP-20 is an American, high-wing, T-tail, single seat glider designed by Richard Schreder.[1]

Design and development[edit]

The HP-20 was designed by Schreder for the FAI 15 Metre Class. The HP-20 prototype was just complete when Schreder lost interest in the project and moved on to work on the HP-21 instead. The sole example of the HP-20 was built by Schreder in his workshop in Byran, Ohio and first flew in 1981.[1][2]

The HP-20 is all-metal with foam wing ribs. The design shares a similar fuselage to the HP-19, but has a different double-tapered wing of smaller area, 102 sq ft (9.5 m2) versus 113 sq ft (10.5 m2) for the HP-19. This gives the HP-20 a higher wing loading and higher best glide speed, although the glide ratio is the same as the HP-19 at 42:1. The airfoil is a Schreder modification of a Wortmann section, designated as Schreder 3. 200 lb (91 kg) of water ballast can be carried. The landing gear is a retractable monowheel.[1]

Operational history[edit]

Even though Richard Schreder died in August 2002, in April 2011 the sole HP-20 was still registered to him.[2]

Specifications (HP-20)[edit]

Data from Soaring[1]

General characteristics

  • Crew: one
  • Wingspan: 49 ft 3 in (15 m)
  • Wing area: 102 sq ft (9.5 m2)
  • Aspect ratio: 24.5
  • Airfoil: Schreder 3, a modification of a Wortmann section
  • Empty weight: 470 lb (213 kg)
  • Gross weight: 970 lb (440 kg) includes 200 lbs (91 kg) or water ballast

Performance

  • Maximum glide ratio: 42:1 at 60 mph (98 km/h)
  • Rate of sink: 120 ft/min (0.61 m/s) at 50 mph (80 km/h)
  • Wing loading: 9.5 lb/sq ft (46 kg/m2)

See also[edit]

References[edit]

  1. ^ a b c d Said, Bob: 1983 Sailplane Directory, Soaring Magazine, page 24. Soaring Society of America, November 1983. USPS 499-920
  2. ^ a b Federal Aviation Administration (April 2011). "Make / Model Inquiry Results". Retrieved 19 April 2011.