Aeronca C-3 Duplex
Single-engine Two-seat Ultralight Monoplane

Archive Photos ¹

1936 Aeronca C-3 Duplex (N17447, c/n A-754) at the Old Rhinebeck Aerodrome, Rhinebeck, New York

Overview ²

• Aeronca C-3
• Role: Ultra-light monoplane
• National origin: United States
• Manufacturer: Aeronca
• Number built: 400
• Developed from: Aeronca C-2

The Aeronca C-3 was a light plane built by the Aeronautical Corporation of America in the United States during the 1930s.

Design and Development ²

Its design was derived from the Aeronca C-2. Introduced in 1931, it featured room for a passenger seated next to the pilot. Powered by a new 36-horsepower (27-kilowatt) Aeronca E-113 engine, the seating configuration made flight training much easier and many Aeronca owners often took to the skies with only five hours of instruction-largely because of the C-3’s predictable flying characteristics. Both the C-2 and C-3 are often described as powered gliders because of their gliding ability and gentle landing speeds - it was almost impossible to make a hard landing with an Aeronca because the pilot could easily see his wheels approach the runway.

The C-3’s distinctive razorback design was drastically altered in 1935 with the appearance of the roundback C-3 Master. Retaining the tubular fuselage frame construction, the C-3 Master featured a smaller vertical stabilizer and rudder with a filled out fuselage shape that created the new roundback appearance and improved the airflow over the tail. With an enclosed cabin (brakes and wing light still cost extra), the 1935 C-3 Master was priced at only $1,890-just a few hundred dollars more than the primitive C-2 of 1929. The low price generated significant sales; 128 C-3 Masters were built in 1935 alone and the 500th Aeronca aircraft also rolled off the assembly line that same year.

A version of the C-3 with fabric-covered ailerons (instead of metal), designated the Aeronca 100, was built in England under license by Light Aircraft Ltd. (operating as Aeronautical Corporation of Great Britain Ltd.) but the expected sales never materialized-only 24 Aeronca 100s were manufactured before production was halted.

Production of the C-3 was halted in 1937 when the aircraft no longer met new U.S. government standards for airworthiness. Many of the C-3’s peculiarities-external wire braces, extensive fabric construction, single-ignition engine, and lack of an Airspeed indicator-were no longer permitted. Fortunately for the legion of Aeronca owners, a grandfather clause in the federal regulations allowed their airplanes to continue flying, although they could no longer be manufactured.

Variants ²

• C-3 — Production variant.
• C-3 Master — Improved variant.
• Aeronca 100 — British-built variant powered by an Aeronca JAP J-99 (a licence built Aeronca E-113C), 21 built.
• Aeronca 300 — Improved British variant of the Aeronca 100, one built.
• Ely 700 — British variant with wider fuselage and two doors, two built.

Specifications and Performance Data (C-3) ³

Type

• Two-seat light monoplane.

Wings

• High-wing wire-braced monoplane.
• Wings, of Clark "Y" section, in two sections, attached at the center-line to the single top longeron of the fuselage.
• Wire-braced above to a cabane and below to the bottom fuselage longerons.
• Structure consists of two solid spruce spars, solid spruce or bass compression ribs and ordinary ribs, double wire drag-bracing, the whole being covered with fabric.
• The ailerons of Duralumin construction are interchangeable.

Fuselage

• Welded steel-tube structure, with five nearly-parallel longerons forward and three from the back of seat aft to the tail-post.
• The section of the fuselage forward is rectangular and aft is faired in a smooth curve.
• The single top longeron acts as the anchorage for the wings forward and forms the apex of the triangular-sectioned fuselage aft.
• The two mid-longerons which form the top of the forward section in the region of the cockpit terminate aft of the cockpit.

Tail Unit

• Normal monoplane type.
• Welded steel-tube framework covered with fabric.
• The fin is built integral with the fuselage.
• The right and left elevators and tail-planes are interchangeable.
• The tail-plane is adjustable on the ground.

Undercarriage

• Divided type.
• Consists of two heat-treated chrome-molybdenum steel axles, which are hinged at their inner ends by large-size pins to two short oleo-shock-absorbers inside the fuselage.
• Airwheels are, standard, but streamline wheels and brakes may be supplied.
• Twin floats may be attached to the fuselage by eight struts and two wire fittings.
• The floats are the Edo type D.1070 of all-metal construction, with five watertight compartments.

Power Plant

• One 40 h.p. Aeronca E-113C two-cylinder horizontally-opposed air-cooled engine.
• Suspended on three points on a welded steel-tube mounting built integral with the fuselage.
• Main fuel tank holding 8 U.S. gallons standard to all machines.

Accommodation

• Closed cockpit under the wings, seating two side-by-side.
• Transparent panels in the wing-roots give upward vision.
• Large windscreen in front of cockpit.
• Landplane has door on one side, seaplane doors on both sides.
• Small windows may be opened for better visibility in bad weather.
• Luggage compartment behind seat.
• Control column and rudder-pedals.
• Cables and pulleys are used throughout the control system.

Dimensions

• Span 36 ft 0 in (10.9 m)
• Length 20 ft 0 in (6.1 m)
• Height 7 ft 10 in (2.37 m)
• Wing area 142.2 ft² (13.2 m²)

Weights and Loadings (E-113C engine)

• Weight, empty: 569 lbs (258 kg)
• Petrol and oil: 64 lbs (24.4 kg)
• Pilot: 170 lbs (77 kg)
• Baggage: 43 lbs (29.5 kg)
• Weight loaded: 1,005 lbs (456.7 kg)
• Wing loading 7.06 lb/ft² (34.4 kg/m²)
• Power loading 25.1 lbs/hp (11.4 kg/hp)

Performance (E-113C engine)

• Maximum speed: 93 mph (148.~ km/h)
• Cruising speed: 85 mph (136 km/h)
• Landing speed: 35 mph (56 km/h)
• Initial rate of climb: 450 ft/min (137 m/min)
• Service ceiling: 12,000 ft. (3,660 m)
• Cruising range: 200 miles (320 km)

References

1. Shupek, John. Aeronca C-3, The Skytamer Archive, Copyright © 1998 Skytamer Images. All Rights Reserved
2. Wikipedia, Aeronca C-3
3. Grey, C.G. and Bridgman, Leonard, Aeronca: The Aeronca C-3, Jane’s All The World’s Aircraft 1936. 1936. pp.247c