The Murphy JDM-8 is a Canadian single-seat ultralight

monoplane 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 ...

home construction Home construction or residential construction is the process of constructing a house, apartment building, or similar residential building generally referred to as a 'home' when giving consideration to the people who might now or someday reside th ...

by Murphy Aircraft of

Chilliwack, British Columbia Chilliwack ( )( hur, Ts'elxwéyeqw) is a city in the province of British Columbia, Canada. Chilliwack is surrounded by mountains and home to recreational areas such as Cultus Lake and Chilliwack Lake Provincial Parks. There are numerous outdoor ...

.Levy, Howard: ''Daryl Murphy's Latest'', Kitplanes, Volume 20, Number 1, January 2003, pages 10-12. Primedia Publications. ISSN 0891-1851 The designation indicates the designer's initials, J. Daryl Murphy and his eighth design.

Design and development

Work was begun on the JDM-8 design in December 1998, but the project was not a high priority and so did not fly until March 2001. The aircraft was first publicly shown at Sun 'n Fun 2000 when it was not yet complete. The JDM-8 is an all-metal low-wing cantilever monoplane designed in two variants, one to meet the

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

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 ...

regulations and one for the non-American markets particularly Canada and Europe. The JDM-8 has a

conventional landing gear Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Term ...

with a tailwheel and can be powered by a

Rotax Rotax is the brand name for a range of internal combustion engines developed and manufactured by the Austrian company BRP-Rotax GmbH & Co KG (until 2016 BRP-Powertrain GmbH & Co. KG), in turn owned by the Canadian Bombardier Recreational Produc ...

engine from 20-80HP. An unusual feature is the upwards folding wing for storage and transportation. The fuselage of the JDM-8 is of semi-

monocoque Monocoque ( ), also called structural skin, is a structural system in which loads are supported by an object's external skin, in a manner similar to an egg shell. The word ''monocoque'' is a French term for "single shell". First used for boats, ...

aluminum 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. It ha ...

construction. The fuel tank is located in front of the instrument panel. The conventional main landing gear for the ultralight version is bungee suspended and includes brakes, while the main landing gear of the homebuilt version is of a sprung design. The tail wheel spring is of 4140 steel and incorporates an

inline skate Inline skates are a type of roller skate used for inline skating. Unlike quad skates, which have two front and two rear wheels, inline skates typically have two to five wheels arranged in a single line. Some, especially those for recreation, ...

wheel. The JDM-8 wing is constructed with an aluminum D-cell leading edge incorporating a high C-channel main spar made from

6061-T6 6061 ( Unified Numbering System (UNS) designation A96061) is a precipitation-hardened aluminium alloy, containing magnesium and silicon as its major alloying elements. Originally called "Alloy 61S", it was developed in 1935. It has good mechani ...

grade aluminum. The rear spar is a similar C-channel that is high and there is a third nose spar that is in height. The wing aft of the D-cell is covered in

aircraft fabric Aircraft fabric covering is a term used for both the material used and the process of covering aircraft open structures. It is also used for reinforcing closed plywood structures. The de Havilland Mosquito is an example of this technique, as are ...

and has a modified NACA 4415 airfoil with a drooped

trailing edge The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 199 ...

. The 11 nose ribs and nine aft wing ribs are made from

hydroformed Hydroforming is a cost-effective way of shaping ductile metals such as aluminium, brass, low alloy steel, and stainless steel into lightweight, structurally stiff and strong pieces. One of the largest applications of hydroforming is the automot ...

aluminum. The ailerons were adapted from the

Murphy Rebel The Murphy Rebel is a two- or three-seat, strut braced, high wing, taildragger monoplane which is sold in kit form by Murphy Aircraft in Chilliwack, British Columbia, Canada.Vandermeullen, Richard: ''2011 Kit Aircraft Buyer's Guide'', Kitplanes, ...

design and are long with a chord. The ultralight version has a greater wingspan to lower its stall speed to below the US ultralight category limit of . With the wings folded the homebuilt version is high and the ultralight version with its longer wings is high. The horizontal

tailplane A tailplane, also known as a horizontal stabiliser, is a small lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyropla ...

is in span to allow legal road transportation on a trailer as most jurisdictions limit trailers to . The ultralight version has an ultimate load limit of +5/-2.7 g and an operational limit of +3.8/-1.8g, while the homebuilt version has an ultimate limit of +5.7/-5.7g and an operational limit of +3.8/-3.8 g. The kit supplied for the JDM-8 was intended to include the parts to make both versions and the manufacturer claimed a construction time from the kit of 800 hours.Downey, Julia: ''2002 Kit Aircraft Directory'', Kitplanes, Volume 18, Number 12, December 2001, page 55. Kitplanes Acquisition Company. ISSN 0891-1851 The completed prototype JDM-8 was displayed at Sun 'n Fun in April 2004, but due to the introduction in the US of the light-sport aircraft category at the same time, no orders were forthcoming and by 2008 the aircraft was no longer listed as being available by Patterson AeroSales, the manufacturer's sole sales agent.

Operational history

In January 2011 there were two JDM-8s registered in Canada, one a

basic ultralight The Canadian Aviation Regulations define two types of ultralight aircraft: basic ultra-light aeroplane (BULA), and advanced ultra-light aeroplane (AULA). Definition Regulation of ultra-light aircraft in Canada is covered by the Canadian A ...

and the other an

advanced ultralight The Canadian Aviation Regulations define two types of ultralight aircraft: basic ultra-light aeroplane (BULA), and advanced ultra-light aeroplane (AULA). Definition Regulation of ultra-light aircraft in Canada is covered by the Canadian A ...

, both owned by the manufacturer.

Variants

;US ultralight version :Single seat, low-wing monoplane with wingspan, powered by a

Rotax 277 The Rotax 277 is a , single-cylinder, two-stroke aircraft engine, that was built by BRP-Rotax GmbH & Co. KG of Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Euro ...

or other engine of for the US ultralight category ;Homebuilt version :Single seat, low-wing monoplane with wingspan, powered by engines up to , including the powered by a

HKS 700E The HKS 700E is a twin-cylinder, horizontally opposed, four stroke, carburetted aircraft engine, designed for use on ultralight aircraft, powered parachutes and ultralight trikes. The engine is manufactured by HKS, a Japanese company noted f ...

for the Canadian

or amateur-built categories

Specifications (FAR-103 Variant)

References

;Notes {{Murphy Aircraft 2000s Canadian civil utility aircraft Homebuilt aircraft Low-wing aircraft Single-engined tractor aircraft Aircraft first flown in 2001 JDM-8

Design and development

Operational history

Variants

Specifications (FAR-103 Variant)

See also

References