Schreder HP-14Schreder HP-14 Type designation HP-14 Designer Richard SchrederCompetition class ClubCrew 1 Length 22.8 ft (6.95 m) Height Cockpit width Cockpit height Wingspan 54.6 ft (16.64 m) Wing area 138.3 ft² (12.85 m²) Aspect ratio 21.6 Wing profile Wortmann FX 61-163 Empty mass ca. 464 lb (210 kg) Maximum mass 728 lb (330 kg) Wing loading 5.26 lb/ft² (25.68 kg/m²) Maximum speed knots ( km/h) Maneuver speed knots ( km/h) Speed in strong turbulence knots ( km/h) Minimum sink rate ca. 110 ft/min (0.55 m/s) Best glide ratio ca. 39 at 48 knots (89 km/h)
The HP-14 was developed from the HP-13, which was essentially an HP-11 fuselage with extended span and the HP-12 wing profile. The wing was later mated to an improved fuselage to become the HP-14.
The 14 used lower wing loading and reduced aspect ratio in an attempt to maximize performance in weak conditions. The HP-14 is built mostly in aviation-grade aluminium, following the belief of its designer that metal gliders could have performance equal to FRP gliders and were cheaper to build. The type features a 90 degree landing flap for approach control, originally operated by a rack and pinion mechanism.
More than 40 of all versions were built in the United States of America and by Slingsby in Great Britain.
The HP-14 is classified in the Experimental airworthiness category reserved for homebuilt aircraft, with the exception of the Slingsby HP-14C variant that is fully Certified.
- The ship has appeared with all three tail styles: the original had the Schreder V-tail, Slingsby produced the HP-14C version with 18 m wing and conventional tail, and the HP-14T version used the HP-14C wing and a T-tail.
- The HP-14C adopted a rechargeable pneumatic system to ease aerodynamic operating loads at high speed.
- As with many homebuilts, a number of builders have made design changes to their ships. In some cases these have been substantial.
- Andre Krutchkoff built his SHP-1 with his own design of fuselage with T-tail.
- Paul Bikle built the T-6, a modified HP-14 with a 17.37 m (57 ft) wingspan and extensive modifications to the control system.
- Otto Zauner constructed an 18 m model, the Zauner OZ-4, later modified with winglets for a span of 19.2 m (63 ft) and a gross weight of 386 kg (850 lb).
- The Preiss RHJ-7 series is a two-seater variant developed from the HP-14.