The Aeronca Model 7 Champion, commonly known as the "Champ", or "Airknocker",[3][5][7][8] is a single-engine light airplane with a high wing, generally configured with fixed conventional landing gear and tandem seating for two occupants.

The Champ was designed for flight training[5][9] and personal use, and was specifically developed to compete with the popular Piper Cub.

It entered production in the United States in 1945, spawning one of the most popular, and longest-produced, light airplane models in the world.

Like its predecessors and initial rivals, the high-wing, two-seat plane has tandem seating, conventional landing gear (tailwheel-equipped), and a small piston engine.

[1][2][4][16] As with many light aircraft of the time, the Champ's fuselage and tail surfaces are constructed of welded metal tubing.

The outer shape of the fuselage is created by a combination of wooden formers and longerons, covered with fabric.

[4][16][18][19] Additionally, an uncommon[6] Champ variant—the 7HC—was produced with an enlarged rear seat allowing two passengers to be carried.

[6] Conventional-gear Champs feature a steerable tailwheel and most have steel tube main gear which use an oleo strut for shock absorption.

[5][7][23] The original model 7AC Champion initially sold by the thousands, peaking in 1946, as Aeronca developed the highest-volume production line in general aviation.

In 1971, Bellanca introduced the 7ACA version of the Champ as a more basic complement to their other designs, as the least expensive, and lowest-performance, commercially produced light plane on the market at the time.

The new production aircraft are type certified, but also qualify to be flown by sport pilots in the United States.

[12][13] Although the fuselage and cowling contours are similar to the original-production models, the new aircraft used the windows, interior, door, and windscreen of the modern Citabria.

[27] Fuel capacity was reduced to 18 US gal (68 L; 15 imp gal) to conserve weight; despite this measure and various others, such as the use of aluminum landing gear legs and bare birch floorboards rather than carpet, the aircraft's payload is inadequate to carry two adults and full fuel simultaneously.

The manufacturer was considering various further weight-reduction measures including the use of the lightened Continental O-200D engine previously offered in the Cessna 162 Skycatcher.

[29] Various versions of the Champ have been tested and produced since 1944, including military, aerobatic, cropduster, tricycle-gear and (as the 402 Lancer) a twin-engined variant.

[6][34] An improved version of the L-16, the L-16B/7CCM featured a 90 hp (67 kW) Continental C90-8 engine, an enlarged vertical tail, hydraulic brakes, and a gross weight increase to 1,300 lb (590 kg); an additional gross weight increase to 1,350 lb (610 kg) is allowed when "Long Stroke Oleo Landing Gear" is installed and placard, "Intentional spinning prohibited when baggage carried", is installed on the instrument panel.

[6] Similar to 7CCM but with Continental C85 engine of 85 hp (63 kW); the derived S7DC floatplane had a gross weight increase to 1,400 lb (640 kg).

[6] 1950 brought the introduction of the Aeronca 7EC, which features a Continental C90-12F engine of 90 horsepower (67 kW),[36] standard long-throw oleo strut main gear, thicker seat cushions, additional interior insulation for noise reduction, an improved heater and electrical system, the addition of a parking brake, and a change in center of gravity for enhanced speed.

An enhanced version called the Champion DeLuxe Traveler offered a metal propeller with spinner, wheel pants, a steerable tailwheel, and navigation lights.

[6] In late 2007, American Champion introduced a revised version of the 7EC, featuring the Continental O-200-A engine of 100 horsepower (75 kW).

[6] Generally similar to 7EC but with a 140 hp (104 kW) Lycoming O-290-D2B engine and modified fuselage structure for increased gross weight.

[6] 7GCA with smaller wings, redesigned empennage, other aerodynamic refinements, deletion of rear-seat flight controls, and minor detail changes.