Summer 2025 Piper L-4H Grasshopper Update

Much test fitting of the major components had to be done before covering.

Restoration Progress

The Grasshopper is nearing completion. Fitting, covering prep work, and actual covering are the primary work happening this month. Prep work for finishing also included the creation of paint masks and stencils by Abby in the art department.

The L-4 with the wings and vertical stabilizer attached, viewed from the right side.

Left side view of the L-4.

Fuselage

Ensuring that everything fits properly and starting the covering process were the recent focus of the work on the fuselage.

Chad and Joe are fitting the boot cowl/firewall assembly.

Close examination reveals where minor trimming and forming need to be done for a perfect fit.

After fitting had been completed, the boot cowl was painted. The visible tabs will be used to attach the windshield.

The wood floor shines in its new coats of varnish. The owner chose to keep the wood showing, rather than painting the floorboards olive drab.

A view of the forward floor shows the rudder and brake pedals.

The internal cockpit fabric is installed and painted.

The carb heat labeling has been done.

This is the left side of the cockpit showing the front and rear throttles, trim, and fuel controls.

The elevator control cables run through these fairleads.

New fairleads help ensure smooth movements of the surface controls.

The observer’s shelf looking back from the cockpit.

The green “V” brace behind the windshield attaches to the left and right main wing spars. This brace stiffens the fuselage in the windshield area and helps to hold the left and right spars together.

The fuselage frame is masked and draped, ready to paint the interior cabin fabric.

A variety of parts are laid out after returning from the paint shop.

This is the lower cowl after painting with primer.

Wing Controls and Attachment

Some of the most critical parts of a light airplane are the wing attachments, struts, control cables, and pulleys.

This photo shows the attachment point where the base of the wing struts join the fuselage.

The strut ends allow adjustments when the final rigging is done.

The aileron pulleys have been mounted.

AIRCORPS AVIATION | 10 Summer 2025 The green internal wing structural parts the wing struts attach to are shown. The control cable and yellow control horn for the aileron are also visible.

The geometric arrangement of the wing and its struts is clear in this image.

A closer view of the strut attachments inside the wing shows the internal bracing wires.

The strut attaches to the wing structure with a bolt through the protruding strut mounts.

One of the seats awaits installation in the cockpit. This will be done after the airframe is covered.

Covering

Stewart Systems products were used for covering. Converting a fabric airplane is always a major milestone!

The first piece of fabric has been attached! This is the rear cockpit fabric.

Here is another view of the fabric rear cockpit wall.

The ailerons are ready for fabric.

The ailerons have been covered and painted with the first coat of finish. This grey layer is a paint designed to resist damage from ultraviolet light.

Fabric covering had been applied to the bottom of the right wing.

Fabric wrapped around the outside edge of the wing as it is attached to the tip bow.

All of this internal bracing will be hidden under the fabric covering.

The wing is placed in a rotating fixture for access to all surfaces while the covering proceeds.

The covering on the top of the right wing is in place.

Mike shrinks the fabric with an iron.

The left wing has been covered, rib-stitched, and the first coat of the UV-resistant paint has been applied.

The left wing is in the paint booth.

One job that seems like a small detail but is critical to strength and airworthiness is the rib stitching. Some rib stitching can be seen in this image of the bottom left wing.