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