March 25, 2013
By Ian J. Twombly
Now that work on the Get Your Glass Sweepstakes Piper Archer has shifted to the instrument panel, the project is in the home stretch. But before Penn Avionics installs the actual instruments, they had to address what the instruments were actually going to mount upon.
When the Archer was built in late 1975, instrument panels were typically a number of pieces of thin aluminum, where the instruments were mounted, covered with black plastic for a cosmetic treatment. In the case of N22ZT, the “old airplane,” that piece of metal was .032-inches thick. And even today, Piper still produces their light singles with multiple pieces of metal for the panel, according to Penn Avionics installer Chris Vinciguerro.
The panel that was just installed late last week on the ”new airplane“ is one piece of .125-inch thick aluminum, reinforced with multiple supports in the back (more on that later). But why even change the panel at all? The short answer is that it looks better. With today’s style reflecting a cleaner, more refined look, plastic is out in favor of metal. Besides, considering Penn can do the design, manufacturing, painting, and installing in house, it makes sense to do it when completely refurbishing a panel. To leave the old panel means to do a significant amount of patching, and that would just not fit with a beautiful new airplane.
The final installation of a new one-piece metal panel is the culmination of a number of different decisions and processes. To begin, a customer identifies his or her desire to have the panel replaced as a part of an installation. Theoretically, an owner could elect to have only the panel changed as an individual work order, but it wouldn’t make much sense. No, the time to do this is concurrent with some new instruments or equipment. Almost immediately after Penn receives the order, they begin work on the panel. “It’s one of the most time-consuming portions of the project,” said Vinciguerro.
Because most aircraft instrument panels function as a structural support, simply taking out the old pieces and replacing them with a new piece is not approved. Each one requires a field approval, and that means being in an area where the FAA allows such a practice. Vinciguerro said when he was working in Seattle, the FAA wouldn’t allow his company to touch the panel. That culture is no doubt changing as the practice becomes more widespread, but problems may persist in certain areas.
Assuming a designated engineering rep buys off on the drawing and concept, Peter Fiorot, Penn Avionics’ designer, gets to work. Fiorot works in computer-aided design (CAD). Doing so allows the customer and Fiorot to quickly change panel elements to get the best result. In the case of the Archer, we went back and forth multiple times on the best location for the engine analyzer and the backup instruments. The Aspen Avionics EFD1000 PFD has that benefit.
Once Fiorot and the customer have finalized a design and Penn has received the airplane (previous steps can be done before the airplane even arrives at the shop), the cutting begins. There are different techniques to complete this step. Some places use lasers, while others use a CNC machine (computer numerical control). Penn Avionics uses a CNC process in multiple steps to produce the right fit. First a test panel is cut, usually out of heavy PVC plastic. That is tested for fit and to make sure all the instruments are in their proper place. Any changes are made in CAD, and then tested again. When it’s time to make the actual panel, a piece of 2024 T 3 aluminum is loaded into the CNC machine and is cut. Then it is cleaned and primed with a self-etching process.
At this point, a human usually intervenes and primes the panel by hand. But in the Archer’s case, the DER wanted to see more support. So Vinciguerro riveted on a few strips of aluminum on the back to make it even stronger (and heavier). After Penn’s Keith Cougar primed the panel, it was time for another decision—what color to paint it. The difficulty here is matching different shades in the interior to the new panel. In the end we picked a shade of gray that will go well with the headliner, sidewalls, and carpet. To describe the color in more detail, however, is futile given the immense amount of shades available. Cougar applied three coats of our chosen DuPont paint color.
Finally, the panel is silkscreened, also in house at Penn. The shop is at a unique point where they have a trained CAD technician, a superb painter, and a master at silk screening. Of course, they are also great at installing avionics equipment.
The benefit to the sweepstakes is that we now have a beautiful instrument panel to compliment new instruments, radios, and other equipment. And we were able to do it with no hassle and in a short amount of time. What more could you ask?
Next week: AOPA Fly-In and Open House preview
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