The Schreder HP-22 was an American
mid-wing
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes.
A monoplane has inherently the highest efficiency and lowest drag of any wing con ...
,
amphibious flying boat,
cruciform tail __NOTOC__
The cruciform tail is an aircraft empennage configuration which, when viewed from the aircraft's front or rear, looks much like a cross. The usual arrangement is to have the horizontal stabilizer intersect the vertical tail somewhere ...
ed, two seat
motor glider
A motor glider is a fixed-wing aircraft that can be flown with or without engine power. The FAI Gliding Commission Sporting Code definition is: a fixed-wing aerodyne equipped with a means of propulsion (MoP), capable of sustained soaring flight ...
project that was designed by
Richard Schreder
Richard E. Schreder (25 September 1915 – 2 August 2002) was an American naval aviator and sailplane developer, responsible for design and development of the HP/RS-series kit sailplanes marketed from 1962 until about 1982. Schreder also fou ...
. None were ever completed or flown.
[''Homebuilders News, ]Soaring Magazine
''SOARING'' is a magazine published monthly as a membership benefit of the Soaring Society of America. It was first published in 1937. The headquarters is in Hobbs, New Mexico. The magazine's article topics include safety issues and accounts of in ...
'', Volume 48, Number 6 page 27, June 1984. Soaring Society of America
The Soaring Society of America (SSA) was founded at the instigation of Warren E. Eaton to promote the sport of soaring in the USA and internationally. The first meeting was held in New York City in the McGraw–Hill Building on February 20, 193 ...
, USPS 499-920
Design and development
The HP-22 project was publicly announced in June 1984 in
''Soaring'' and, in comparison to Schreder's previous glider designs, was intended for "much easier building and for more versatile fun-flying when it's finished".
The aircraft was intended to accommodate two people in
side-by-side seating
Tandem, or in tandem, is an arrangement in which a team of machines, animals or people are lined up one behind another, all facing in the same direction.
The original use of the term in English was in ''tandem harness'', which is used for two ...
under a
bubble canopy
A bubble canopy is an aircraft canopy constructed without bracing, for the purpose of providing a wider unobstructed field of view to the pilot, often providing 360° all-round visibility.
The designs of bubble canopies can drastically vary; s ...
. The engine was to be mounted above and behind the cockpit and to retract rearward to lie in a bay when not in use. The mid-mounted wing was to have a span of and a constant chord, built with an
aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...
spar
SPAR, originally DESPAR, styled as DE SPAR, is a Dutch multinational that provides branding, supplies and support services for independently owned and operated food retail stores. It was founded in the Netherlands in 1932, by Adriaan van Well, ...
, foam ribs and covered with aluminium skins. The tail would be similarly constructed. The wings also included coupled
ailerons and
flaps.
The intention was that the flying boat hull would be constructed from four panels of
PVC foam covered on both sides with
fiberglass
Fiberglass (American English) or fibreglass ( Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass clo ...
at the factory, with the builder just epoxying them together around pre-formed bulkheads. The landing gear was to consist of a retractable
tricycle gear
Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle ...
, with the main gear swiveling aft and nose wheel retracting forward to act as a docking bumper on the nose. The landing gear main wheel design included
disc brakes. The planing hull featured a normal step cut out and Schreder indicated that if this was shown to create too much drag during flight testing that he would design a retractable fairing for it. His intention was to have retractable tip floats that would swing outboard to form wing tips in flight in the same manner as on the
Consolidated PBY Catalina
The Consolidated PBY Catalina is a flying boat and amphibious aircraft that was produced in the 1930s and 1940s. In Canadian service it was known as the Canso. It was one of the most widely used seaplanes of World War II. Catalinas served wi ...
, which Schreder had flown during the
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...
.
Despite its flying boat design, the HP-22 was intended as a soaring motor glider and the designer estimated its glide ratio at 30:1 and its minimum sink speed at 2.0 feet per second.
Schreder started work on the HP-22 before the
HP-21
The HP-21 was a scientific calculator produced by Hewlett-Packard between 1975 and 1978. It was designed as a replacement for the HP-35, and was one of a set of three calculators, the others being the HP-22 and HP-25, which were similarly built ...
was finished and did not finish, register or fly either aircraft.
Specifications (HP-22 projected)
See also
References
{{Schreder Sailplanes
1980s United States sailplanes
Schreder aircraft
Amphibious aircraft
Flying boats
Mid-wing aircraft
T-tail aircraft