Schreder / HP-18

Glider Reg. Number: N1YV

1976-84

Design & Development

The HP-18 is a Richard Schreder-designed metal Racing Class sailplane that was offered as a kit for homebuilding during the 1970s and 1980s.

The HP-18 is a flapped (15-meter) sailplane featuring a V-tail and 90-degree flaps for glidepath control. The fuselage is composed of a prefabricated composite forward fuselage and a semi-monocoque aft fuselage, and features steeply reclined seating and a side-stick controller although modifications using a conventional stick have been made.

As most homebuilts, the HP-18 has been constructed with many variations in detail. Perhaps the most significant version is the Super HP-18 developed by Canadians Ed Hollestelle and Udo Rumpf, which features a modified wing airfoil, winglets, a front-hinged canopy, conventional control stick and higher ballast capacity.

Major features:

• Very low cockpit with reclining seating position
• Sidestick (changed to conventional stick by some homebuilders)
• Two-piece canopy (changed to single piece forward opening by some homebuilders)
• V-tail that folds upwards for easy storage
• Wing structure composed of spars with caps pre-machined from solid aluminum plate and aluminum wing skins bonded to closely spaced foam ribs
• Fiberglass fuselage pod, wing tip skids and tail fairings
• Aluminum tail cone
• Winglets added by some homebuilders
• Water ballast carried inside the hollow aluminum wing spars
• Typical Schreder trailing edge flaps/airbrakes partially interconnected with the aileron

Specifications

General characteristics

• Crew: One pilot
• Length: 23 ft 2.4 in (7.07 m)
• Wingspan: 49 ft 2 in (15.00 m)
• Wing area: 113 ft² (10.5 m²)
• Aspect ratio: 21.4
• Empty weight: 470 lb (213 kg)
• Gross weight: 970 lb (446 kg)

Performance

• Maximum speed: 150 mph (240 km/h)
• Maximum glide ratio: 38
• Rate of sink: 126 ft/min (0.6 m/s)