The Birth of a MonarchThe development of the Monarch LS experimental

aircraft

By: Matthew HoffmasterApril 4, 2009

It all began with paper and pencil. Ok, big paper, lots of pencils, and lots of erasers.

After a lot of planning, we began construction. The first step was fabricating a 16 foot workbench. The bench was covered in paper so we

could draw the plane’s profile on it in full scale.

After laying out the design, measuring, and estimating, we ordered the first bulk order of raw materials. Everything was bought and shipped in

8 foot lengths for ease of shipping.

One-by-one, the alloy steel is cut to fit the drawing on the table. The pieces are then tack-welded in place.

When the primary/basic structure of one side was complete, the second was built directly on top. This creates two identical sides.

The two sides are separated and squared off. They will go on to form the main steel “cage” that will support the wings, engine, pilot, and

passenger.

In similar fashion, two sides are created out of extruded aluminum angle to form the tail section of the fuselage.

The two halves (towards rear of photo) are covered in sheet metal to give them strength. They are lined up to the proper angles, and

fastened to the steel cage. More extruded angles are later fastened between the sides to hold them in position (not shown).

Form blocks are made out of wood. They will be used to form various metal parts. These particular form blocks will be used to make the upper

half of the tail section as well as the numerous wing ribs.

Here is the tail section of the fuselage with the metal ribs formed by the previous blocks attached. This will give the tail its shape and give the

sheet metal something to fasten to.

Paper patterns are made for most sheet metal parts. The paper is easy to cut, handle, and write on, and will stay in place with just tape. The patterns allow us to see any problems before cutting into an expensive sheet of aluminum.

Metal is cut using the paper patterns and temporarily held in place with “clecos” (the silver and copper things sticking out everywhere). After the

fit is confirmed to be correct, the sheets will be fastened with rivets.

With the other pieces of aluminum removed, one of the last two pieces for the tail is cut and fit. This piece is a more complicated square-to-round section that

requires careful planning and layout to make it fit correctly.

Here the completed horizontal stabilizer is sitting on the bench waiting to be mounted to the tail of the aircraft.

Horizontal and vertical stabilizers, as well as rudder and elevator are completed and mounted to the tail.

(Left) - Left side main landing gear leg finished and waiting for paint. (Top Right) - Fabricating components for the brakes.

(Bottom Right) - Tail landing gear is machined out of solid aluminum bars and extruded aluminum angles.

Wing ribs – 4’ x 12’ sheets of aluminum are cut into dozens of these rectangles which are seen here stacked together. Lightening/stiffening holes are cut out, then the metal is cut to shape and formed over these

wooden blocks.

The finished wing ribs are attached to the front and rear wing spars.

A close-up view of one of the control bell cranks.

The wing is supported and clamped to the table to lock it in place while the skins are drilled and fastened.

Gas tank mounts are fabricated out of solid aluminum rod and strips of ½” thick nylon. Large holes are cut in the nylon the size of the tanks, then the

strips were cut in half across the holes. Aluminum rod was threaded to accept a nut on each end and formed into a “U” shape.

The main skins have been fastened to the wing, and the wing tank has been mounted with the previously seen clamps. Each wing will carry

about 6 gallons of fuel in addition to the main tank.

The main gas tank sides cut out of a large sheet of aluminum. Fittings for inlets, outlet, and sensors are welded in place before the sides are

welded together.

After the sides are tack-welded in place, the store-bought fuel level sending unit is checked for fit. Once everything is confirmed to fit

correctly the tank will be welded completely and checked for leaks.

With the tail section and main skins removed for extra room to work and maneuver, the gas tank is dropped into place to check the fit and

machine the mounting points.

After making a paper pattern, the windshield is cut out of polycarbonate sheet and formed around the fuselage. (Here you can see the temporary

white plastic coating that protects it from scratches)

Experimenting with upholstery - Fabricating an armrest out of foam, vinyl, and plywood to sit atop the center console. The console will house the intercom/radio

headset connections…and cup holder of course.

Starting with paper “cutouts” of the instruments, I begin laying out the instrument panel. This approach allowed me to move key components

around until I was satisfied with the layout.

Fabricating the motor mount. After carefully setting up a jig to hold things in the exact alignment, the steel tubes are cut to fit and welded in

place.

Finally, the whole plane was taken completely apart, all steel parts were prepped for paint and painted.

Left – Riveting the aluminum skins to the door framesRight – Checking the fit of the polycarbonate side windows prior to installation

Building up the aluminum structure that will support the windshield and roof and streamline the roof with the contour of the wing and fuseloge.

Similar view with the roof skins riveted in place.

A view of the mounted power plant, a 2180 CC Volkswagen engine converted by Revmaster Aviation for aircraft use.

~ A MONARCH is born ~Although much work has been done since this photo was taken, there

are no photos which show the airplane more complete looking than this.