The Diehl AeroNautical XTC Hydrolight is an American amphibious flying boat ultralight aircraft that was designed and produced by Diehl AeroNautical in the 1980s.Cliche, Andre: ''Ultralight Aircraft Shopper's Guide'' 8th Edition, page E-46. Cybair Limited Publishing, 2001. The prototype first flew in March 1982, with production of kits commencing the following year.

Design and development

The XTC was the first amphibious flying boat to comply with the US

FAR 103 Ultralight Vehicles Ultralight aircraft in the United States are much smaller and lighter than ultralight aircraft as defined by all other countries. In the United States, ultralights are described as "ultralight vehicles" and not as aircraft. They are not req ...

rules, including the category's maximum empty weight of . The aircraft has a standard empty weight of . It features a cantilever

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 ...

, a canard foreplane, dual vertical tails, a single-seat, open cockpit, re-positionable

tricycle landing 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 g ...

and a single engine in pusher configuration. The aircraft's hull is made from

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 ...

, while the wing has a

Kevlar Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s a ...

- epoxy

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, ...

with its flying surfaces covered in bonded

Mylar BoPET (biaxially-oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and a ...

. Its span wing is located behind the cockpit. Some aircraft were delivered with optional enclosed cockpits for all-weather flying. The

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...

repositions clear of the hull for water landings and is sprung on all three wheels. The nose wheel is steerable. The control system is three-axis, with the canard for pitch, twin rudders for yaw and spoilers for roll control. The XTC is very aerodynamically clean and produces a 14:1

glide ratio In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the lift generated by an aerodynamic body such as an aerofoil or aircraft, divided by the aerodynamic drag caused by moving through air. It describes the aerodynamic efficiency under giv ...

. Strongly built, the aircraft is rated for +8/-8 g. The standard engine supplied was the twin-cylinder,

two-stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of ...

, single ignition, horizontally opposed

KFM 107 The KFM 107 is a two-cylinder, two-stroke, single ignition, horizontally opposed aircraft engine designed for ultralight aircraft and motor gliders.Cliche, Andre: ''Ultralight Aircraft Shopper's Guide'' 8th Edition, page G-5 Cybair Limited Publis ...

aircraft engine of .

Operational history

In service many owners replaced the KFM 107 powerplant, as it left the aircraft underpowered, especially for water operations. Owners report that the XTC is pitch sensitive in flight.

Specifications (XTC)

References

{{reflist 1980s United States ultralight aircraft Homebuilt aircraft Single-engined pusher aircraft Amphibious aircraft Canard aircraft Mid-wing aircraft