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Panel Modifications (Dinosaurs, Dumpsters, and Dollars) Part VII

I’m sure that for most of us, our years in school are fondly remembered. I truly enjoyed the years I spent getting my industrial design degree at the University of Cincinnati. That said, there is a definite downside to attempting to live in a world dominated by the concepts of form and function. Just ask my wife how frustrated I get when I come face to face with bad design. Something as simple as a poorly designed cork screw can send me into an extended dissertation on bad cork screw design!

Sometimes, however, not everything about an object is poorly designed…

We’ve all noticed an out-of-place feature that can be a visual distraction from an otherwise good design. Some of the tailfins on 50’s cars definitely detracted from the otherwise acceptable design for a car of that period. Or, how about the nose wheel violating the pleasing and functional lines of a Piper Tri-pacer? And then there are some wild paint jobs that have been popular lately that try real hard to make even a Bonanza look ugly.

When it comes to Beech instrument panels, one things that can absolutely distract from a beautiful new panel installation is a poorly designed or ill-crafted glareshield. Drives me crazy! A well designed, beautifully finished and installed custom panel with a glareshield that barely extends out past the face of the panel is not much glare reduction in my book. Then when you turn on those glareshield lights that are so close to the face of the panel, all that gets illuminated is the upper panel paint. Trying to read the instruments in an instrument panel with a glareshield like that is like flying into bright sunlight with a very dirty windshield. This is dysfunctional design at its highest level. The point is, a custom built glareshield presents a perfect opportunity to apply the design principle of form follows function to create an aesthetically pleasing and very functional instrument panel cover. Icing on the cake!

Here at Air Mod, custom designed glareshields come in two basic types. The first is a modified stock or after-market glareshield. The second type is one that is completely fabricated in-house from raw materials. The majority of the time we are able to modify an existing glareshield to fit a new or modified instrument panel. We make this decision after the panel is rough cut and temporarily installed in the airplane. The two driving forces behind the decision of glareshield type are panel height and windshield configuration.

A sloped windshield will definitely accommodate a taller instrument panel. In fact, we had originally intended to keep the stock non-sloped two-piece windshield in the M35 Bonanza we referred to so often in this series of panel articles. Both the owner and I like the look of vintage Bonanzas. When we temporarily installed the new taller panel, stock S35 glareshield and non-sloped windshield, two problems became apparent. First, the glareshield would be so close to the inner surface of the windshield that it would be impossible to clean the windshield without removing the glareshield. The second problem was how difficult it would be to actually remove and reinstall the glareshield.

The fix here was to install a sloped windshield. This solved the glareshield problems, provided more working room between the taller panel and the sloped windshield, and allowed for the installation of a better, fixed defroster system. The functional advantages of a sloped windshield definitely took precedence over our aesthetic preference for the classic look of a 50 year old Bonanza.

 We were using a Beryl D’Shannon full-panel mod kit, so we had the fiberglass glareshield that is included with the kit. To enhance instrument lighting, we wanted to install red and white selectable lights under the glareshield’s aft lip. To make this lighting effective as possible, we needed to extend the overhang of the glareshield by three inches. Being that the Beryl D’Shannon glareshield is molded in fiberglass, this can be easily accomplished by riveting a .020” 2024T-3 aluminum splice at the widest part of the glareshield. Low tech non-structural hardware store pop rivets can be used to fasten the splice together. We then apply an 1/8” layer of body filler to smooth the splice area. With a 1/2” layer of backing foam and a nicely sewn and mounted black anti-glare cover, the splice will be invisible. The extended glareshield looks better than the original short one, and the additional overhang really shields the entire instrument panel and instruments, a real benefit on bright sunny days. Looks better and works better!

By installing a new sloped windshield at the same time we are building a new instrument panel, we can more easily do all the intricate fitting and trimming of the glareshield with the windshield removed.

Another detail that makes a big difference in the function and appearance of the Beryl D’Shannon glareshield is to increase the dimension of the aft lip. We riveted a .020” 2024T-3 aluminum augmentation piece along the entire fiberglass lip. By increasing the dimension of the lip, we can gain enough depth to install incandescent lighting that is shielded from the pilot’s eyes. Also, by adding this aluminum lip, we reinforce a formerly somewhat delicate part of the glareshield that, over time will often crack as the glareshield is flexed during installation and removal.

(For those who are doing this work yourself, the Beryl D’Shannon glareshield can be purchased by calling Scott at 1-800-328-4629.)

One final issue worthy of mention is how to get the glareshield to fit nicely at the windshield base. On some panel mods, we install full depth radios at the very top of the radio stack.  In order to get a good fit of the glareshield, an aluminum bump out piece must be fabricated and grafted to the glareshield in the area above the radio stack. Again, we use hardware store pop rivets, .020”2024T-3 aluminum sheet, and body fillers to do the job. Once padded and upholstered, the glareshield looks great.

In rare and extreme cases we have built a custom .020” 2024T-3 aluminum glareshield. We start by making a cardboard pattern, then hand-form the basic shape of the glareshield in aluminum. To get a contoured lip on the overhang we used ½”x ½ “ dead soft aluminum angle, formed to emulate the contour of the finished edge of the glareshield overhang. We then use the hardware store pop rivets on the 1½” centers to secure the ½”x ½” angle to the glareshield. A .020”x ¾” aluminum fascia strip is riveted to the vertical face of  ½”x ½” angle, creating a finish lip at the exposed edge of the glareshield overhang.

It’s important to use un-tempered dead soft angle for this area in order to have a frangible glareshield that will fold down and not be so strong as to cause injury if a person’s face should come in contact with it in an accident. As an additional safety enhancement, we bond a very firm ½” thick rubber foam to this finish lip area. Back in the early ‘70’s, when we got our initial approval for this design, we actually had to hit this aluminum glareshield with a frozen chicken until the glareshield collapsed onto the face of the instrument panel. If the skin on the chicken wasn’t broken, the glareshield passed the test. That’s what they wanted. (We did pass the chicken test – works for me!)

Due to the cost of constructing a field-fabricated glareshield as well as the availability of both factory original and after-market glareshields, we only choose the hand built option as a last resort.

Once the glareshield hard-shell is fabricated or modified, and the lighting is installed, it’s time to get into the padding and upholstering phase of the job. Years of light airplane flying and fixing has convinced me that the best material with which to cover a glareshield is unquestionably a semi-gloss ultraviolet light tolerant, non-combustible black vinyl. Covering a glareshield in a light color that matches the interior is a major mistake. On bright sunny days there will be enough reflected glare in the windshield to almost allow you to log the time as IFR. Semi-gloss black absorbs light and almost eliminates glare, allowing us aging pilots to better see other airborne traffic.

Attempts have been made in the past to cover glareshields with various black fabrics. Black fabric will definitely do a better job of absorbing light than even semi-gloss vinyl. Two problems, however, will eventually rear their ugly heads. First, windshield cleaners will be absorbed into the porous cloth and be impossible to get out. The second problem is sun tolerance. Black fabrics eventually begin to fade and then literally disintegrate long before aircraft vinyl will. We use genuine naugahyde US393 black expanded vinyl. We now have glareshields that have been in service in that hostile environment for thirty-five years. The stitching may have faded a little but otherwise they look fine.

One last word on glareshield cover materials: never use leather. Sun and heat will accelerate the aging of the leather, causing it to crack and shrink. The shrinking of the leather will cause severe warping of the glareshield hard-shell. The picture says it all.

The first step in the actual glareshield covering process is to bond the ½” thick high impact black foam to the exposed aft lip area of the glareshield. We bond ½” urethane foam to the main body of the glareshield, and then sew a two-piece top stitched vinyl cover that is patterned to fit the precise shape of the glareshield. Once the vinyl cover is stretched and glued at the edges to the glareshield, we will neatly bond fine-weave black grosspoint cloth to the exposed underside of the glareshield. In an effort to reduce cabin sound levels, we will bond a ½” layer of flame-proofed black closed-cell, sound absorbing, neoprene rubber padding to the back side or the glareshield. Think of all that noise behind the panel close to the fire wall. Well, that noise can blast through an un-insulated glareshield and be reflected aft right into the cabin. Every little bit of noise reduction helps. The final product is a durable, pleasant looking, form-fitting, easily installed and removed glareshield that will last for years.

One final note on the subject of glareshields… For those of you who have 1969 and newer Barons, Bonanzas, and A36’s with the often broken-up glareshields, Aircraft Spruce (877-477-7823) has a very cost effective and high quality after-market glareshield. This product is fabricated using thermally stable high strength fiberglass and comes with the defroster plenum molded to the forward end of the glareshield. Such a deal!

Well, that pretty much covers the subject of glareshields…no pun intended! Next month, we will wrap up this series of instrument panel articles by discussing how we paint and placard these new panels. Till then, fly safe!

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