h.r. (bart) everett

Technical Director for Robotics, 237T | SPAWAR Systems Center, San Diego
Bldg. 622 Seaside | 53406 Woodward Road | San Diego CA 92152-7383

everett@spawar.navy.mil

 Fiberglass Mockups: A-4 Skyhawk

I constructed this 1/3-scale fiberglass replica of the A-4 Skyhawk, flown at the time by the Blue Angels precision flight demonstration team, in the late 70s while stationed in Montgomery, AL. I had initially intended to build a go-cart for my 4-year-old son, but we could only find three lawn-mower wheels in my shop, so we opted to build an airplane instead. It started off as a rather crude triangle of plywood with a seat up front, but our creative juices got to flowing and we kept thinking of ways to make it better and more realistic. Basically completely out of hand, in other words…


We first embellished by adding a three-dimensional fuselage structure atop the triangular wing, and closed in the cockpit and nose section as shown here with ¼-inch plywood. Next came the empennage with its horizontal and vertical stabilizers, complete with moveable flight surfaces (elevators and rudder) cabled directly to the rudder pedals and control stick in the cockpit. The ailerons on the trailing edges of the wings were similarly actuated, but the flaps immediately below them were motorized. Two 12-volt car batteries provided the necessary power.


Now that we had electrical options there was seemingly no end to the possibilities, such as the obvious cockpit, landing, collision avoidance, and tail lights, followed by a linear actuator for raising and lowering the tailhook mechanism. Twin gun barrels were then installed, in close to the fuselage on the leading edges of both wings, their internal strobe lights synchronized to a motor-driven mechanical noise-maker controlled by the trigger switch on the control stick.


Next came a rather impressive engine simulator, fashioned from a modified electromechanical siren and a hair-dryer blower, appropriately instrumented with microphones that fed a 12-watt stereo amplifier. The amplifier speakers were situated such that the turbine whine produced by the siren appeared to come from the engine intakes, while the roar of simulated jet exhaust produced by the blower mike poured forth from the tail pipe. The respective speeds of the siren and blower, as well as the amplifier volume, were controlled by the engine throttle in the cockpit. The characteristic inertial lag of turbine response was fairly realistically simulated by a series of thermal-delay relays. (Single-board microprocessors at that time were not yet an available option.)


Once the basic actuators and associated wiring were installed, we began building up the body and wing surfaces with fiberglass, using a tennis ball as a form for the nose, short lengths of garden hose to define the air intake cowlings, and poster paper to create the rounded portions of the fuselage. For extra stiffness, the upper wing surface was built up of two layers of fiberglass over a ¼-inch plywood skin, which in turn was glued down upon an internal rib structure to achieve the desired airfoil contour. This allowed the wing assembly to easily support the envisioned loading to be imposed by a never-ending progression of climbing admirers and future naval aviators.


Viewed now from the starboard side, the upper fuselage has been fiberglassed from the air intake back to the rear exhaust, with the horizontal stabilizer temporarily removed. The in-flight refueling probe is seen extending just forward of the intake and running parallel to the lower fuselage towards the nose, and the wingtip navigation lights are now in place. The initial implementation of the landing gear, however, has the aircraft sitting way too low to the ground. We cheated a bit also in providing a dual nosewheel configuration to reduce stress on the steering mechanism.


This front-quarter view shows the fiberglass in a more advance stage of completion, with the horizontal stabilizer reattached to the empennage. The landing light is clearly visible under the starboard wing, and simulated bomb loads hang in the racks just inboard of the mainmounts, but the Sidewinder missile rails are not yet installed. The windscreen forward of the cockpit is starting to take shape.


This was a hormone-inspired nighttime test of the cockpit, landing, navigation, and anti-collision lights. With the engine at full power, of course, just to convince the neighbors that we had really lost it. The other neighborhood fathers were typically not too enthralled with my advertised creativity…


Here the proud test pilot is seen conducting his preflight checks. Note the landing gear has been lengthened to yield the correct elevation and attitude, and sports additional detail such as simulated oleos, brake lines, nosewheel steering linkage, and a weight-on-wheels switch. The extended height, however, suggested incorporating dual tires on the mainmounts as well for added stability.


Almost ready for painting, shown here trailored in to work to show the visiting Admiral. Sidewinder rails are now installed beneath the wings just inboard of the wingtips, and the ejection seat inside the cockpit is beginning to take shape.


I convinced the Blue Angels to paint the finished product, shown here next to the real thing at NAS Pensacola, so we could use it as an officer recruiting aid for aviation programs. Note the working tailhook below the rear fuselage, and the semi-functional instrument panel just visible in the cockpit. The surface finish was so smooth and shiny you could actually see your own reflection. The enlisted maintenance personnel were so taken with the working functionality of the model that I received a big box of additional doodads from their spares to enhance the realism even further.


Suited up in his custom flight gear, my son Todd climbs into the cockpit out on the flightline in preparation for his television debut.


Sporting a not-so-military haircut, Todd explains the finer points of fiberglassing to CDR Bill Newman, Blue Angels Commanding Officer (No. 1).


Todd borrowing CDR Newman's flight helmet for his official squadron photo.


Front view of newly painted 1/3-scale model, which shows the illuminated gunsight in the center of the windscreen. I left the finished product with the Navy Recruiting District, Montgomery, AL, when I was transferred in 1980 to the Naval Postgraduate School in Monterey, CA. Its whereabouts today is unknown.


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