The following is very long ... my excuse is that the Wissler WA-6 and WA-9 were fairly obscure types.
AVIATION, May 24, 1926, page 793
Two Low Power Touring Airplanes.
THE WISSLER AIRPLANE COMPANY of Bellefontaine, Ohio, has recently produced two interesting airplanes of comparatively low power which have successfully passed their tests. Both planes were designed by C. H. Wissler, aeronautical engineer, who has been interested in aviation since 1909 and has designed and built many experimental airplanes. Little has been heard of his work, however, since a great part of it has been along experimental and research lines covering wind tunnel tests, stress analysis, propeller design, etc.
The first of the two planes to be described is the WA-6. It is designed as a sport plane and is said to be very easy to fly and very economical in upkeep. The engine, an Anzani 75 hp. air-cooled radial, takes about four gallons of gasoline and [?] gal. of oil per hour.
Constructional Details
The machine is a tandem two-seater single bay biplane. The main planes are wood and wire construction and covered with standard grade A cotton fabric, doped with four coats of lead-acetate, two coats Buff Titanium and finished with two coats of Valspar varnish. The main spars are I section spruce and are backed with 3/32 in. steel the entire length for extra strength on account of the very thin wing section used. The ribs have white pine webs lightened out and have spruce cap strips. Each wing panel has four box ribs to take compression of the high tensile steel wire used for internal drag bracing. Ailerons are mounted on top wings only. No center section is used, the top wings joining over the center line of fuselage and being mounted on four short struts cross braced with aircraft cable.
Like the main planes, the horizontal stabilizer, elevators and rudder are of wood and wire construction. The rudder is of the balanced type. All ribs, both in the main planes and in the tail surfaces, where joined to the leading and trailing edges, are reinforced with copper strips. Side stress in the ribs is taken care of by tape in Pratt truss form running the entire length of each wing panel in four different places. The tail surfaces are braced in a like manner. No fixed vertical fin is used on this plane.
The fuselage is also of the usual wood and wire type, the longerons being ash from the rear cockpit forward and of spruce to the rear. The fuselage is covered with aluminum from the engine bed plate at the nose to the back of the rear cockpit and from that point to the rudder post the covering is cotton fabric. Dual control is installed and both cockpits have ample room and comfortable seats. The engine is mounted directly on the heat treated nose plate and is readily accessable at all times. In fact, the engine can be dismounted from the plane in less than half an hour by one man. The gasoline and oil tanks are mounted in front of the front cockpit and are easily removed if need be. All necessary instruments are mounted in both front and rear cockpits.
The Landing Gear
The landing gear is of the conventional two wheel Vee type with straight rigid axle, rubber sprung. Vee's are of streamline spruce reinforced with steel plates lightened out. The tread of the wheels is 5 ft. and wheels are wire with 26 in. by 3 in. cord tires. The tail skid is of ash and rubber sprung and so mounted to give proper drag without undue stress on the rear of the fuselage.
All bracing and control wires are of Roebling’s aircraft cable of proper size to insure ample strength in all cases. Flying wires are double and landing wires are single. Owing to the short span of the wings, no drift wires are necessary, which fact cuts down the resistance and, therefore, adds to the high speed. The horizontal stabilizer is braced from below with steel tube and the rudder is braced with solid steel wire from the hinge line to the top of the stabilizer on each side. All control wires are exposed which, of course, renders
inspection of these a matter of ease.
Performance
The airplane has, apparently ample power with the 75 hp. aircooled Anzani 6A-3, radial engine. During the experimental tests of the machine, the engine was throttled down from the normal speed of 1500 r.p.m. to 1100 r.p.m. and the plane continued upon an even keel with hands off. The balance of the plane is such that very little movement of the controls is necessary. On one occasion, when the engine was cut at an altitude of 5400 ft., the ensueing glide extended for a period of 28 min. before the landing was made, which gives some indication of the flat gliding angle of the airplane. In a case of engine failure, this should give ample time for the location of the most suitable landing place. On another occasion during the tests, it is said that, when stalled, there was no tendency for the machine to fall off on one or the other wing tip. And, lastly, the machine was shown to possess ample controlability and maneuverability during the tests.
The general specifications and details of the Wissler WA-6 are as follows:
Span, top wings 27 ft.
Span, lower wings 24 ft.
Chord, both wings
Wing section Wissler 16
Wing area, including ailerons 184 sq. ft.
Area, both ailerons 16 sq. ft.
Area, stabilizer 10.5 sq. ft.
Area, both elevators 12 sq. ft.
Area, rudder 5 sq. ft.
Wing Gap at center 4 ft. 3 in.
Wing Gap at strut 4 ft.
Stagger 8.75 in.
Incidence 3 deg.
Dihedral, top wing 1 deg.
Dihedral, lower wing 2 deg.
Length, overall 19 ft. 3 in.
Height, overall 8 ft. 3 in.
Weight, light 736 lb.
Weight, fully loaded 1208 lb.
Useful load 472 lb.
Gasoline capacity 13 gal.
Oil capacity 3 gal.
Duration 3 hr.
High speed 120 m.p.h.
Cruising speed 85 m.p.h.
Landing speed 40 m.p.h.
Climb in 1 min 700 ft.
Climb 10 min 5000 ft.
Wing loading 6.5 lb./sq. ft.
Power loading 16 lb./hp.
Factor of safety [?]
The Wissler WL-9
The Wissler WL-9 is also a two-seater machine and a single bay biplane but the seating arrangement is side by side. The main planes are of the usual wood and wire construction covered with grade A cotton fabric and doped with five coats of clear acetate, Valspar and finally aluminumized. Main spars arc spruce of rectangular section. Ribs are of Pratt truss type and have spruce cap strips with truss members of the same material. Each wing panel has four compression ribs of solid % in. spruce webs and spruce cap strips. Internal drag bracing is of high tensile steel wire. Ailerons are mounted on the upper wings only and are of ample size to insure control. As in the WA-6, there is no wing center section. The top wing panels meet over the fuselage center line and are mounted on a caban[e] of four short struts cross braced with aircraft cable. Side stress in the ribs is taken care of by tape cross bracing in Pratt truss form the entire length of each wing panel, in four places.
The stabilizer, elevators, fin and rudder are of wood, wire and steel tube construction. The main spars of these members are of wood, cross braced with wire and the leading and trailing edges are of oval steel tubing.
General Construction
The fuselage is rectangular in section and braced with aircraft cable forward of the cockpit and with spruce members to the rear. The sides are covered with plywood and the turtleback and bottom of the fuselage are covered with fabric. The longerons are spruce, as are the horizontal and vertical struts. The plywood covering is in three sections and of different thickness. The front section, from the cockpit forward, is [?] in. thick, the middle section is 3/16 in. thick and the rear section is [?] thick. All plywood is birch three-ply. As stated the cockpit is arranged for side by side seating so that the passenger can, at all times, converse
with the pilot. This feature also makes this plane very suitable for training students to fly as every move made by the instructor can be seen by the student. Either dual or single control can be used. The engine is mounted directly on the usual steel bed plates used with rotary engines. The engine, an 80 hp. Le Rhone rotary, is very readily accessable. Gasoline and oil tanks are mounted forward of the cockpit and are easily removed if necessary. The instrument board is furnished with all necessary instruments.
Undercarriage
The chassis is the conventional Vee type and has a hinged axle, rubber sprung. The Vee’s are of steel tubing, faired with Balsa wood. Tires are 26 in. by 3 in. on wire wheels with a tread for the undercarriage of 5 ft. The tail skid is ash, metal shod and so mounted to cause no undue strain on rear of the fuselage.
All bracing and control wires are Roebling standard aircraft cable of a size to insure ample strength under all conditions.
On the test flights of the WL-9 the climb was proved to be better than 1000 ft. per min. with a ceiling of 18,600 ft. The average take off was accomplished in 110 ft. with pilot alone and in 200 ft. with a passenger. Even with a 280 lb. passenger, the take off distance was only 230 ft and at a distance (straight away) of 500 ft. from a standing start, the plane had climbed to a height of 150 ft. On another test, the plane attained a height of 400 ft. in a distance of 1000 ft. straight away and the pilot held the plane on the ground for a 200 ft. run. The length of run upon landing was found to average 140 ft. The above figures are taken from actual tests and are not estimated.
In these and other tests the plane was stalled and showed no tendency to spin. Control and stability were good at all speeds, with power both on and off. The plane has a flat glide of 1 in 10.