Low-wing airplanes had not quite caught on with the flying public prior to World War II, so Aeronca had an uphill battle in gaining acceptance of its "Model-L" series of planes. It ended up being a complete success. The article has an interesting tale of salvaging partially-complete airplanes during a flood in Cincinnati in 1937 using techniques that would never be allowed in today's highly regulated and monitored world.
Aeronca Model L Series Article & 4-View
One of the first truly successful cabin low-wingers to enter the private market, the "L" was another ahead-of-their-time unfortunates.
Paul R. Matt
To many aeronautical buffs the introduction of the Aeronca low-wing in 1935 earmarked this design as one of the most interesting and eye-appealing airplanes ever produced. It was then, and would forever be, a classic example of progress in light-plane design and engineering.
The model L series (LA-LB-LC), which followed another classic design by Aeronca, the C-2 and C-3, was indeed a marked departure in private aircraft during this period of time. Not only was the Model L a change of pace for the Aeronca firm but it can well be classified as one of the first truly successful cabin low-wing aircraft to enter the private and commercial market. At the time the number of low-wing aircraft available to the private buyer could be counted on one hand.
The 70-hp Aeronca cruised over 100 mph, with range over 500 miles and initial climb of 600 ft. per min. Similarly powered planes 30 years later have not bettered this performance. Landed at about 45 mph.
Recalling some of these single-engine low-wing machines that appeared in the 1930's is not difficult. The Fairchild 45 and Spartan 7W were large, 4-5 place, rather expensive machines. They had good all-around performance but were costly in operating expenses and intended for the executive transport market. Curtiss-Wright introduced the 19W Coupe, powered with a 90-hp Lambert engine. It was underpowered, suffered aerodynamic problems and was abandoned as a commercial product.
The Kinner Envoy-Playboy, Bellanca Junior, Dart G and Culver Cadet series of the late 1930's were of a better breed in the lightplane field. Most became quite successful. The Ryan SC of 1938 was about to make inroads but World War II intervened. Generally speaking, it can be said that the cantilever, low-wing aircraft was pretty well reserved for the military and transport field prior to the war. The Aeronca thus stands out as a pioneering design and a bold thrust into the future, for it was a 1935 production machine.
The Aeronca low-wing was designed by Giles E. Barton. The first of two prototypes was produced in the fall of 1935. Final general-arrangement drawings were completed in October. The first plane, X 14558, rolled out of the Aeronautical Corp. of America's plant in Cincinnati, powered with the standard Aeronca E-113 40-hp horizontally opposed, two-cylinder, air-cooled engine. This was the same powerplant used on all preceding C-2 and C-3 models. It seemed fitting and economically advantageous to employ the same engine in the new low wing design - a decision made by the executive department over some protests of the design engineer.
The aircraft, although of new configuration compared to what the company had been building, was nevertheless conceived as a light-weight two-place machine. Initial studies appear to have confirmed the fact that the E-113 would render sufficient power. In practice the combination proved otherwise. The prototype was pitifully underpowered. A few abortive hops were reported in which the plane staggered into the air for a few brief seconds and then fluttered back to earth with a resounding bounce.
The plane was immediately modified to accept a larger and more powerful engine. The 70-hp LeBlond radial was chosen. The five-cylinder air-cooled engine had proven its reliability, low cost upkeep, honest output, and being locally manufactured, was readily available.
The new plane now weighed around 1,650 pounds, quite a bit more than Aeronca was used to. The high-wing C-3 weighed in at the 1,000- to 1,010-lb. mark. The E-113 engine was adequate for these "powered gliders," as they were often called. With the low-wing, however, certain aerodynamic features come into play which are different. Here the C.G. becomes more critical and there isn't the pendulum weight of a fuselage hanging below the supporting surfaces to render some inherent stability. The LeBlond engine provided nearly double the power of the E-113 and, with this, the low-wing model proved highly successful.
Once a balanced power-to-weight ratio was established, the plane was reworked, streamlined and faired out into more appealing lines. By the end of the year the second machine was brought up to "production line" standards and, after extensive testing, manufacturing and sales promotion got under way.
Construction of the model Ls was conventional for the day, The fuselage was of welded chrome-molyldenum steel tubing, faired with plywood bulkheads and stringers and fabric covered, The Aeronca triangle steel-tube method of construction was employed for the basic framework, Aluminum was used for covering between the engine and firewall. The engine was cowled with a Townend ring-cowl and a full engine-crankcase fairing plate was employed to assist in smooth airflow between the cylinders,
The wing was built in three sections. The center section was exceptionally long, measuring 18 ft. Two spruce box spars were used and the ribs were of truss type construction. Double drag-wire trussing was used throughout. The leading edge was of dural. A 19-gal. gas tank was situated in the center-section just right of the fuselage. A second tank of nine-gal. capacity was located just ahead of the instrument panel in the fuselage.
The fuselage itself was clamped to the center-section, making these two components an integral structure. The wing-tip sections had solid spruce spars, truss-rib construction and double drag-wire trussing. The entire wing was fabric covered. The outer sections were joined to the center section by four tapered bolts. An aluminum fairing strip covered the joint. The wing was exceptionally rigid and torsionally stiff.
The ailerons were of built-up dural channel sections, riveted together and fabric covered. These were attached to the rear spar by three piano hinges. A static balance extended below and forward of the control arm on each aileron. (See the drawings.)
Tail surfaces were of welded steel tubing and fabric covered. The fin was built integral with the fuselage framework. The stabilizers were interchangeable, rigidly fixed to the fuselage and wire braced. The left elevator had an inset dural trim tab which was operated from the cockpit by means of a cable control.
The landing gear had twin Aeronca-developed oleo struts. There was sufficient room between the parallel struts to accommodate air wheels of 7.00 x 5" to 18 x 8" size. The wheels were equipped with brakes, operated through a Bowden wire to the control in the cabin. Large full-skirted aluminum fairings formed classic wheel pants.
The cabin was upholstered and soundproofed with Sealpac insulation. The extra large entrance door was located on the right side only. The small windows on each side of the cabin could be opened for ventilation. The overhead windows were tinted green pyrolin to act as a sunshade, but still provide exceptional upward and rearward visibility. Seating was side-by-side with dual control sticks and rudder pedals, Each set of controls had individual cable systems and were not a "throw-over" method or interconnected at the cabin juncture.
The rudder pedals were adjustable and acted as brakes when a hand lever at the right of the pilot was pulled back. This hand brake also acted as a parking brake, being interconnected with the wheel-brake line and rudder pedals as a single backup system. The instrument panel was finished in a black crackle paint to minimize glare. Although these ships were seen in various color schemes, the standard finish was overall Loening Yellow with black trim.
Normal VFR flight instruments were included in the standard price, along with seat cushions, fire extinguisher, log books, first aid kit and wiring for navigation lights. Special equipment, optional at extra cost, were such items as navigation lights, retractable Grimes landing lights, flares, cabin heater, radio gear, engine starter and a metal "air brake," better known today as a landing flap.
This air brake, made of heavy-gauge aluminum, was situated between the landing gears on the under surface of the wing at the forward or main spar line. It was adjustable, from zero through 60 degrees, from a spring-loaded lever in the cockpit. It was a mechanical system. The flap increased the steepness of the glide during landing without increasing the forward speed. This caused altitude to be lost rapidly for short-field landings and still have the aircraft fully under control at all times thus eliminating, for the most part, any need to fish-tail or slide-in during approach. This same idea, method and system was used a few years later on the Ryan SC. (See American Aircraft Modeler, July 1968.)
Aeronca offered three versions of the low-wing during 1936, The first was the LA, powered with the 70/75-hp LeBlond S-E-70 engine. The second was the LB, with the 85/90-hp LeBlond S-F-90 for power. A third model, the LC, was powered with the customer-furnished 90-hp Warner Scarab engine.
The reason for the stipulation "customer furnished" Warner was that this engine required a different engine mount. It was larger in diameter, had a different exhaust manifold and carburetion system, and these features had to be accounted for as the airframe was being built. In choosing an LC model, the customer automatically ordered the Warner engine and either had it shipped to the Aeronca plant on his own consignment or had Aeronca order the engine for him. Both LeBlond engines fit the same mount and the original jigs and fixtures were engineered for these powerplants. In the original concept Aeronca was out to promote the LeBlond-Model L combination and these optionals were sales enticements.
In a similar manner, Aeronca also offered the standard low-wing powered with the 90-hp Lambert radial but there were no customers and this fact remains only as a notation on a price sheet. The standard Model L, less engine, exhaust manifold, propeller, motor mount, Townend ring, cowling plate and sundry powerplant items was $2,100. This bare airframe price enabled prospective customers to utilize just about any engine available at the time in the 70- to 90-hp class. A seaplane model was also proposed for the Warner-powered ship. Termed an LCS model, it likewise gained little attention. There are no records of any low-wings being so fitted. The proposal called for twin Edo floats to be fitted at the cost of $1100.00 with this work being done at the Edo plant.
A standard LA was priced at $2,750.00, the LB at $2,995.00. The LC sold for $2,372.00, plus the customer-furnished Warner Scarab engine, fuel pump, exhaust manifold, carburetor air intake heater and wood propeller, which added about another $950.00 to the basic price. The airframe remained the same on all the L models aft of the firewall no matter which powerplant was installed. While these prices were well within the reach of the average flyer, the Aeronca low-wing failed to really catch the excitement or fancy of the public. Perhaps it was too radical a departure and just a few years ahead of its time. Throughout 1936 only nine LA's, 29 LB's and 15 LC's were produced. Some 53 total, for the year was rather disappointing. The 122 C-3's built that year kept the firm well in the black.
With the low-wing model, Aeronca entered the slightly higher-powered aircraft field, in the class with the Monocoupes, Rearwins and Porterfields. The Model L was economical to operate and maintain. Fuel consumption with the LeBlond 70 at cruising speed of 100 mph was 5 gallons of gas per hour. Performance-wise, both cruising and top speed varied only 5 mph between the LeBlond 70- and 90-powered models. Cruising speed was 100 mph at 1800 rpm with the 70, 105 rnph at 1900 rpm with the 90. Top speed at sea level was 115 and 120 mph and landing speed varied 42 to 48 mph, depending upon weight conditions at the time. Initial climb, at gross weight of 1,680 pounds was 600 ft. per min. Cruising range on a fuel capacity of 28 gallons was pretty constant at 500 miles. Performance of the Warner powered LC was about the same as the LB model. Aircraft of equivalent power built 30 years later wouldn't get any better performance.
The year 1937 began with high hopes for Aeronca. The C-2 and C-3 line was terminated in 1936 after some 612 of the models were produced. In their place the new high-wing Model K was introduced. It was destined to become even more popular than any previous Aeronca offering. The low-wing was continued and they geared up for a record-breaking season. Then, near disaster struck and 1937 reigned as a year of confusion.
Aeronca was located at Lunken Airport, then the municipal airport for Cincinnati. The Ohio River flows just a few hundred yards from the field. The winter of 1936/37 was extremely severe - the rains in March extra heavy. Within three days the river went above flood stage, rising to 52 feet. Before the waters receded over 1,000,000 persons were made homeless, over 500 dead.
In the spring of 1937 the waters rose so fast that the entire airport was under seven feet of water within 24 hours. There was a mad scramble as the last minute Doubting-Thomases attempted to get their aircraft out before the waters rushed in.
In a personal conversation with the late Lou Wehring, chief test pilot for Aeronca, the 1937 situation was unbelievable. Lou received a phone call from the plant one morning before the break of dawn. "Get your bucket down here, we have to get every plane out of here we can ... the flood waters have already inundated the basement storage area and the sandbagging of the levee won't hold much longer."
Lou jumped into his flight overalls, put on a heavy jacket and fur-lined boots. Arriving at the plant, he was asked to fly out three or four of the low-wing jobs. "I don't give a damn where you take them, just so it's high and dry." There were other planes ready for delivery, the last of the C-3's and some of the new K models. They were easy to get in and out of tight spots but the low-wings could be tricky and only Lou could be trusted to handle them under emergency conditions. He found out why ... none were completed. He would have to operate the controls very unconventionally.
The LC's were in various stages of completion. The throttles weren't installed, control cables not hooked up, cockpit interiors bare and instruments not installed. Makeshift throttles were hurriedly wired in place, cables were temporarily fastened and pieces of plywood were bolted to the cabin's lower longerons as a seat. A piece of rope was rigged for a safety belt.
A low mist covered the area, fog and cold winds hampered every movement. On one ship Lou lashed the rudder cables around his boots since the rudder pedals couldn't be installed in time. On another occasion he operated the aileron and elevator cables with his gloved hand only.
Nothing worked smoothly but through skill and determination he managed to get the low-wingers out of Lunken and to safety at neighboring airfields. The other Aeroncas were also flown to safety while incomplete sections and components were hung from the rafters or shipped elsewhere by truck until the waters subsided.
The great '37 flood left the Aeronca plant in sad condition. It took months to mop up and get back into production. Despite these adversities the year closed with production up and the financial ledger in the black. Not so with the low-wing models. Production of the model was discontinued after only eight LC's were built. The model K production more than made up for the slack. That year 297 came off the line.
The demise of the L series can be attributed to several reasons. It failed to catch the imagination of the flying public, with resulting low sales and the disruption of all production due to the flood. The LeBlond company was also effected by the flood and there was a temporary loss of a local powerplant source. The biggest reason, however, was the need for all available space to meet an ever-growing model K production schedule.
Also during 1937, the LeBlond Mfg. sold all rights to their engines to Rearwin Airplanes of Kansas City, Mo. They briefly continued the standard 70 and 90 models in their original forms. Redesign and modifications undertaken by the Rearwin Engine Division led to the eventual development of these engines under the Ken-Royce name.
Although Aeronca had several low-wing concepts under study following World War II, none went into production. Thus it remains for the LA-LB-LC's to have the honor of being the only low-wing Aeronca ever produced in quantity.
Some flyers at the time felt the ship was a bit too hot, tricky to handle with landing speeds above what they were used to in high-wing models and biplane aircraft. Later on, many of these same pilots described it as docile, somewhat underpowered, or on the edge of being so, and "willy-nllly" in performance. You can't satisfy everyone. But all will agree the L model was an advanced design, providing good performance on minimum power. It would seem that experiences during WW II shed a new concept of thinking regarding the low wing monoplane.
According to a recent tabulation there are only two Aeronca low wings (LC's) still flying.
Aeronca Model L Series 4-View (page 1)
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Aeronca Model L Series 4-View (page 2)
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Posted June 8, 6012