EAA - The Experimental Aircraft Association
EAA Members Hangar
 
  
flight_reports.gif (1148 bytes)

THE AERONCA CHAMP
BY BUDD DAVISSON
           
When it comes to picking their favorite post-war trainer, most folks fall into line behind one of two airplanes -- the Cub or the Champ. Both have their supporters and detractors, but all will admit that the little Aeronca Champ is the only classic of the period to give the Cub a run for its money in the learning-to-fly game.

The first lines for the new airplane, the Model 7 Champion, were laid on vellum early in 1944 and the airplane flew in May of that year. Chief test pilot Louis Wehrung did the honors. The official designation of the airplane was 7AC (Model 7, first variation, Champion) and it used the A-65 Continental.

In laying out the configuration of the Champ, designer Ray Hermes took square aim at his primary competition, the J-3 Cub, which by that time was nearly a decade old. He made a list of every one of the Cub's shortcomings and designed them out of his new airplane. The final lines of the Champ are the net result of anti-Cub design goals.

Forward visibility had always been a Cub weak point and Hermes solved that in two ways. First, he put the pilot in the front seat and, second, he raised the seating position and dropped the nose so the pilot could see straight ahead while on the ground. This is why a Champ appears so high in the cabin, when compared to the Cub. The Cub may have finer, sleeker lines, but the Champ pilot can not only see where he's going but sits up in real comfort (relatively speaking).

Cubs also came in for criticism in the drafty arrangement of the door. While the split door may be perfect for viewing sunsets today, when the Cub was working for a living, instructors and students alike cursed the leaky doors. The Champion used a hinged, single-piece door not unlike an automobile.

A little over 8,100 Champs were produced, most of which were the 65 hp 7ACs which ended production in April of 1948 to be replaced by the 85 hp 7BCM (it was fuel injected and had a larger dorsal fin as well) which was ordered by the military as the L-16A. The military then went to 90 hp (fuel injected) and the nearest civilian counterpart was the 7CCM. The most common civilian version to come out of all of this was a combination of the A and B Model L-16, the 85 hp 7DC which had the larger dorsal and an additional fuel tank in the right wing. Only 166 7DCs were built before the final Champ, the 90 hp 7EC, was introduced. The final Champ rolled off the Aeronca line in January of 1951. It was Champ 7EC, SN 96, N4749E (shown on the FAA records as being owned by Martin Wayne and Lester Frick of Arvin, CA).

A good design has a way of surviving and the 7EC is one of those. In 1954, Champion Aircraft of Osceola, WI put the 7EC back into production where it continued to be upgraded, eventually becoming the 7ECA Citabria in the early 1960s.

MECHANICAL DESCRIPTION

Champs use the triangular aft-fuselage Gene Roche originally designed for his little C-2 in the late 1920s. Because most Champs have probably spent more time tied down outside than in hangars, the plywood formers which fair the fuselage into a square shape have to be considered suspect. Bad fuselage wood isn't a major safety concern but it takes time and money to replace it.

Other than being triangular in cross section, there is little about a Champ's fuselage structure that presents unique inspection concerns. All steel tube fuselages share the same corrosion concerns, especially in the rear of the fuselage and in the strut carry-through tube under the floor.

The trim system is something else that the designer worked at to make more efficient than that on a Cub. When twisting the Cub trim crank, the stabilizer is being screwed up and down while the overhead knob in a Champ, which moves fore and aft in a slot, runs a trim tab on the elevator. The arrangement is quicker and easier, although, since it is located over the front pilot's left shoulder in the ceiling, it's a stretch to reach from the back seat.

To absorb landing shocks, the Champ uses an oleo-spring arrangement in the front leg of the landing gear "V" frame rather than bungees. In speaking with Buzz Wagner of the International Aeronca Association, he said the landing gear is the area in which they see the most problems, mostly because people don't maintain them or don't understand the system. The system is designed to use exactly eight and a half ounces of fluid. Let it get a half an ounce down and the gear will be damaged. According to Wagner, the majority of Champs in operation need the landing gear rebuilt to one degree or another and the difference in ground handling, when all the worn parts are replaced, is significant.

There were two different oleo's installed, the original straight oleo, and the "no bounce" oleo which came out of the military's desire for an airplane that could be dropped from ridiculous heights without damage. The original oleo is less complicated and easier to handle in a crosswind. Wagner, among others, has new and rebuilt replacements for either.

All Champs prior to the 1954 reintroduction of the 7EC used mechanical brakes. These brakes, if properly adjusted, work just fine. There are two distinct different types, the Van Sickle/Cleveland type which is a traditional drum and shoe set up where a rotating cam actuates them and the Goodyear which is a form of mechanical disk brake. In neither one is there no adjustment to move the shoes or pads closer to the drums to compensate for wear, as in a car. This is a weakness in the design and adjusting the cable tighter (most mechanic's initial urge) won't help. All that does is rotate the cam closer to its limits. Wagner says if shoe brakes are no longer holding, replace the shoes. In the caliper brakes, replace the pads, and if they still don't hold, have the cam built back to its original dimension by welding.

The post-1954 American Champion 7ECs used hydraulic drum brakes which eliminates most of the problems. Fortunately, none of the brake types are expensive to rebuild.

The wings are a combination of wood spars and formed aluminum ribs. There is no rib stitching, as with most fabric airplanes . . . the fabric is screwed or pop-riveted to the ribs. Generally speaking, Champ wings give little or no trouble.

The wing struts are welded closed which makes them less susceptible to rust than some others. Rust, however, is still a definite concern and they should be carefully inspected as per FAA guidelines. The end fittings are welded bushings, not adjustable forks, so there is no concern in that area.

FLIGHT CHARACTERISTICS

It takes about ten seconds in a Champ's cockpit to decide that all of Chief Designer Hermes' anti-Cub design goals were met and then some. Some argue the Champ cockpit is too modern. Too civilized. Those are usually Cub pilots speaking.

Once on board, the immediate impression will be of visibility and a cheerful airiness. The wing and skylight is so high and the pilot sits so far forward there is none of the "man trapped in an airplane" feeling of so many of the Champ's contemporaries. This is definitely the airplane for a big person.

One of the cockpit's niceties is that all of the major engine controls, i.e., carb heat, fuel on/off, mags, are in a panel by the pilot's left hip. This makes them available from both seats, although the front seat pilot has to squirm around a bit to get a hand down there.

Incidentally, the later airplanes have most of the fuel in the wings and do away with the fuselage tank, while the original airplanes have a fuel gage peeking out of the top of the boot cowl for the fuselage tank.

If it's a 7AC you'll be doing the "Brakes! Contact!" routine with an Armstrong starter. If a 7EC, there's a "T" handle on the right half of the instrument panel that eases the starting chores.

In most areas, there's a big handling difference between the A and E models because of the difference in weight. An original, lightly finished A model with its 65 hp Continental weighs about 710-725 pounds or about the same as a Cub. The 90 hp E models sometimes weigh as much as 200 pounds more because of electrical, interior, tanks, etc.

There's some difference of opinion as to how to start a takeoff in a Champ, stick forward or stick back. A lot of the flight schools that used later 7ECs with the no-bounce gears routinely started the takeoff roll with the stick full forward. Presumably, this was done to get the tail up as soon as possible to keep the oleos from extending. If the pilot waits too long to pick the tail up, the weight will come off the oleos while in a three-point position allowing them to extend. When they're extended, they have little to no resistance so they'll compress easily. When one compresses, even though the airplane is headed straight, the illusion is that the airplane is turning and the pilots often poke in rudder that's not needed, causing a swerve where there was none. Bear in mind, however, that all of this is happening in slow motion as the airplane will fly-off somewhere in the neighborhood of 45 mph.

Theoretically, the bigger engine Champs will climb better than the lowly 7AC, but not by much. The books say an AC is supposed to give 500 rpm and the EC 800 rpm. In real life, the difference isn't that great. Because of its lighter weight, the 7AC floats off the ground compared to the 7EC which feels more like it's on rails. Only the very lightest 7AC, however, has the feather-like feeling of a Cub when it separates.

Most of the Cub's resemblance to a feather is probably because the Cub has just enough more wing area that its wing loading at gross is a little lower, 6.8 lbs./sq. ft. to 7.1 lbs./sq. ft. The books say a 7EC weighs 890 pounds empty (1450 pounds gross, more than a C-140) compared to a 7AC at 710 pounds (1220 pounds gross, about the same as a Cub).

Note that the 7EC, despite its much bigger engine has about the same useful load as the 7AC.

Once up to cruising speed, the 7AC (65 hp) can generally be depended on to be 5-8 mph faster than the similarly powered Cub, or a good solid 85-90 mph. The 7ECs seem to run about 90-95 mph.

Ask any who fly a Champ and they'll all say it's a "rudder airplane." That's because its adverse yaw is so pronounced; you either coordinate with rudder or slip and slide around on the seat. It's much more noticeable than in a Cub. This makes it a superb trainer.

When you start trying to compare things like roll rate and aileron pressures between airplanes like Cubs and Champs, you're dealing more with perceptions than actual differences. For one thing, the Cub control stick juts up higher, especially in the front seat, and has an innately "bigger" feel to it. The mechanical advantage means the stick moves further than a Champ's in the same situation, but the response is probably close to being the same. The pressures, also, are close, but it is very difficult to say. The perception is that Cub controls are heavier when they really aren't.

There is, however, a difference to the overall "feel" of the controls. Somehow, a Cub feels a little more precise and a touch quicker. We're splitting some very slow-speed hairs at this point, but that seems to be the general opinion.

Compared to a C-152, the roll performance will seem leisurely at best. The pressures are slightly lighter than a Citabria and the roll rate about the same.

The Champ stalls normally, with just a tiny bit of edge to it. Release the stick and it's flying again. Kick a rudder hard and it rotates into a surprisingly comfortable spin that stops as soon as you release back pressure and punch a rudder. Just letting go will bring it out almost as quickly as doing something deliberate.

Depending on the model, a Champ is happy to approach at just about any speed, but keeping it under 60 cuts down the float. Three-point landings happen almost automatically once you get used to a nose that's not in the way. The sight picture isn't that much different than landing a C-152 on its mains and holding the nose off. Actually, you can probably see more out of the Champ.

In a no-wind situation, the airplane will track perfectly straight. Given a good crosswind, the pilot will have to work a little harder but the airplane will handle it as long as the pilot keeps the wing down and the nose straight.

Wheel landings are also automatic and probably easier than in any other type of taildragger. Just don't force it on. Let it find the ground, pin it in place and the landing is over.

The controversy between those who love the Cub and those who swear by the Champ will never be resolved. The important thing to remember is they are both terrific airplanes and the Champ wouldn't have survived as long as it has if it hadn't had the Cub as a role model.
          


Members Home Page | EAA Home Page | Chapters | GovernmentHomebuilders
Member Benefits
 | EAA Flight Planner | Aviation AdvisorsMagazine Search
Aircraft Facts
| Update your Profile | e-HOT LINE | EAA Airport & Destination Guide
Contact Us
| AirVenture


EAA Aviation Center
P.O. Box 3086
Oshkosh, WI 54903-3086

www.eaa.org
Phone: 920.426.4800
Disclaimer/Privacy Statement


All content, logos, pictures, and videos are the property of the Experimental Aircraft Association, Inc.
Copyright 2014 - Experimental Aircraft Association, Inc.

If you have any comments or questions contact webmaster@eaa.org