Building a Better Panel

Advice on converting older panels to a T-group and ridding the airframe of ancient wiring and plumbing.

Ive owned a 1967 Skylane for eight years and during every IFR flight, I had dreamed of getting my scatter shot flight instruments corralled into some meaningful arrangement on the panel.

To me, that means T-grouped, ergonomically clustered analog data that I can scan quickly and interpret accurately.

Unfortunately, as is the case in many 1960s vintage aircraft, my panel was designed with no particular logic. Piper seems to have been the first manufacturer to use the basic T-six design, in part as a response to the training boom of the mid-1960s. Cessna came along with a spacious, casually T-grouped panel in the 1968 Skylane, following Beech, which created an airline-type T-grouped panel for the P-model Bonanza in 1962.

Nonetheless, there are still plenty of half-this, half-that panels out there, requiring an eye-careening scan and some interesting head-spinning approaches on a wet ILS.

What to do? Id thrown tons of money at engine overhauls, instrument overhauls and new radios, but without the basic T, the panel was still miserable to scan.

I looked into custom panels, most of which simply re-arranged a few holes to get a T-group effect. The 1967 Skylane has a low-cut floating panel, which makes it difficult to stack an attitude and directional gyro directly over the control column, which is where I wanted it.

No one seemed interested in doing it. Then I heard about Russ Anderson, who had a fresh take on the idea.

Anderson is a Cessna 340 owner and partner in a Minneapolis company called Specialty Tool and Engineering. They do grinding, milling and lathe work on small metal things, designing on computers and using computer-driven machinery to make the stuff: CAD-CAM.

Anderson, I learned, had a program specifically designed for instrument panels. When you get the panel the way you want it, you punch a key and a computerized milling machine cuts the design from a sheet of aluminum.

The holes for the instruments and the panel itself are exactly the right size for the airplane. Exactly. When you put an instrument into one of these holes, it goes swish, thunk. When the avionics shop puts the panel in the airplane, the technician just screws it in-swish, thunk.

Having seen contemporary panels, Id grown accustomed to gauges that dont quite fit, bunged up screws, file marks and warping. None of that in Andersons 340 panel. In his world, everything is measured to four places and 1/8th inch is a football field.

Panel By Fax
So heres how it worked: I designed the perfect panel myself, using a series of sketches on paper. I finalized my sketch and faxed it to Anderson where Dave Schaeffer sat at a computer and pulled drawings of instruments from his database. He dropped them into a computerized 1967 Skylane floating panel on his screen.

That done, Schaeffer faxed the results back to me before I had a chance to get a cup of coffee. I made some changes. I moved the LOC/GS head a tad to the left and up. I moved the VSI and I added a digital OAT to the left side. Fax. He redrew the scheme. Fax. I changed things again, like an old man trying on all the shoes in the store. Next, I flew the airplane to Modern Avionics where manager Kurt Schendel reviewed the computer drawing, made a few suggestions and showed me how the CAD/CAM has even planned where post lights go and determined the screw sizes, taking into account the out-of-round nature of some instruments. All I had to do is schedule time at Modern to install my final design and fly T-grouped, back into the sky.

Schendel interpreted my ideas and made adjustments so the airplanes new panel complied with FAR Part 23, thus avoiding the need for FAA field approval. Getting field approval for major mods such as this can be simple or it can be hell; either way, it takes a rain forest of paper and more time than I was willing to invest.

My drawings finally passed muster and Schendel approved the milling of a new panel. In the end, I got my panel in two days, just as Schendel promised. With instruments and radios in place, I can scan the gauges and interpret the data without inducing vertigo.

Ive got a panel thats been cleaned up and cleaned out, so Im not ferrying around 30 pounds of dried out, tied-back harness installed when Lyndon Johnson was president.

The bottom line: $1500 and two days of downtime for a panel in a 29-year-old airplane thats certainly as useful as the one Cessna is installing in the 1998 Skylane. Im confident that the redesigned panel adds considerable value over an equivalent airplane with the older style design.

Further, theres a safety factor involved. The new panel is far easier to scan and although it may be an exaggeration to say the old one induced vertigo, its also true that the new panel is easier on the eyes.

Second, ridding the panel of some-if not all-worn and chafed wiring is something every owner should consider doing. Three decades of summers and winters and constant vibration take a toll on wiring; it simply wont last forever.

General Advice
Obviously, with so much sophisticated avionics going into so many older airframes, panel re-design is becoming more common, with a handful of shops specializing in the sort of redo that Specialty Tool and Engineering does.

Naturally, the CAD-CAM guys say computers do it best but, truthfully, conventional drilling and punching is probably as good, assuming the shop doing the work is competent and, above all, patient.

Nonetheless, CAD-CAM services are readily available and some avionics shops are installing their own equipment. If your shop doesnt have the CAD/CAM equipment, you may have to find the service on your own and coordinate the job with the shop doing the avionics installation. We think its worth the effort to find a shop that specializes in panel reconstruction, however.

The real value of CAD/CAM emerges when you plan a panel that places instruments close together, something thats hard to do with traditional tools without distorting the panel.

Be sure your tech gets in on the early planning to help sort out plumbing problems behind the panel and between the panel and the structure of the glareshield. Any modification of the glareshield or airplane structure itself will likely be cause for an STC and/or FAA field approval via Form 337.

Get the CAD/CAM service and your shop talking early on in the project, before the airplane is disassembled. This will avoid grounding the airplane while problems get sorted out. Some aircraft, such as Cessnas, have panels made up of three components: a left-side floating panel (a non-structural sheet of aluminum on cushioned spacers); a radio stack component panel and a so-called fixed panel on the right. The fixed panel is structural and a type certificate item. Changing or modifying it will likely require field approval. Get your techs opinion-and a cost estimate-about your dreams for the right-side or any proposals to change the structure of the instrument panel as a unit.

Over the years, readers have told us about other shops specializing in complete panel work. One is Aerotronics, at Billings, Montana, which has been in the panel business for 20 years and has dedicated a 13,000 square foot hangar for projects ranging from experimentals to Super Cubs and Citations.

Martin Elshire told us that Aerotronics routinely does complete panel restorations and handles the FAA paperwork for field approval on major mods. He confirmed what weve been told about STCs.

STCs are a problem, Elshire says. Once youve STCd a panel project , the next guy has to do exactly what the previous guy did. Exactly. If the second guy wants to switch the VSI with the altimeter, he cant do it with an STC in effect. With a field approval, you just get individual custom projects signed off with the local FSDO, and its no problem for us. Elshire said that he produces a computer-generated, full-size color panel layout for the pilot to try on before the project rolls. We dont punch metal until the pilot sees it, and approves every detail, Elshire says. Aerotronics panel re-dos run from $1000 for a simple floating panel to about $5000 for the left side, the lower panel and the right side.

Mod Works
The point of redesigning a stock aircraft panel is to manage the cockpit more efficiently without suffering eye strain. Human factors is the buzzword and ergonomics is what the 21st century cockpit is supposedly all about. They didnt know about that stuff in 1962.

At Mod Works, in Punta Gorda, Florida, the shop that produced AOPAs Ultimate Arrow, Tim Coons specializes in one-piece panels for Mooneys, Cessna 172s and the Piper PA-28 airframe.

Under a grant from NASA, Mod Works researched the human factors of panel design, including the pilots position, eye movements, eye-hand correlations and developed a scoring system of ergonomic factors that led to the development of a standardized panel.

Coons says that the panel of the future will be a standardized product that has high ergonomic values. He believes that custom panels are often created by pilots who think they know what they want and where instruments ought to be, but discover later that the placement doesnt produce what they expected.

What you are buying from Mod Works is a new panel, all switches, a VMI 1000 Engine Monitor and a harness that ties your instruments and avionics to the modular system. The price for an ultimate panel assembled by Mod Works is $15,000; in kit form $12,000.

If you want to buy all the bits and pieces, sans the engine monitor, youll pay about $3500. The panels are expected to be available during the first quarter of 1998.

Air Mod
Air Mod in Batavia, Ohio, also specializes in panel renovations. Dennis Wolter says his shop reviews the pilots wish list and inspects the airplane with an eye toward the integrity of the existing harness and panel structure. An airplane that has been around for 20 or 30 years has probably seen some haphazard electric and avionics installations. The first thing we do is recommend a cleanup of the panel space. Wed like to rebuild some positive circuit protection and get rid of the potential for maintenance induced failures. Then we can deal with the pilots wish list.

Wolter often goes on the road with a slide show that illustrates the horrible and sometimes dangerous installations that have arrived in his shop during the past 20 years. He is emphatic that owners get the mess cleaned up before they spend money on cosmetic panel re-dos.

Wolters calls himself a pencil-and-straight edge engineer who has an industrial design degree. The shop builds panels the old fashioned way, with fly-cutters and sanding drums, creating cut-outs tailor-made for individual off-the-shelf instruments.

When an owner has developed a design and Air Mod agrees with the integrity of his ideas, a full-size drawing is made before the work is done. A full-panel modification including replacement of stock switches and breakers-all requiring FAA field approvals-may cost from $7000 to $10,000.

Avion Research
Avion Research in Sunnyvale, California, produces panel kits for Cessna and Piper aircraft. The kit includes all metal panels, shock-mounted panels, switch panels and center-mounted radio stacks. The glareshield includes dimmable florescent instrument lighting.

Obviously, these kits-which are intended to be installed by a local avionics shop-represent major mods and have to be installed under STC, with field approval.

Final Thoughts
At the lowest end of the panel re-design spectrum are shops that will simply comply with the wish list and tie back some wire and tie-in the new box. In a relatively new airframe, that may be fine. But the shops weve listed here-and many we havent-urge a full evaluation of whats behind the panel, including the ancient wiring, old-style circuit breakers and cracked and chafed tubing.

Having seen the mess behind my own panel, I have to agree. Fixing those potential problems before they occur is a priority.

Beyond that, draw up your wish list and figure out where you want things to be. If you dont know where you want things to be, give Mod Works ergonomic panels a look.

And dont go into a panel redo project with tight purse strings. If youre going to overhaul the panel of a 30-year-old-airplane, youll have to spend at least $2000, probably closer to $5000 to $10,000 if you update avionics, overhaul instruments or modify the structure of the airplane. (If major mods are necessary, be patient and plan for the down time. Dont do it against a hard deadline.)

In my case, a $1500 expenditure may have made the airplane more salable but whether it increased the value by a like amount is debatable.

The more you spend, the less youll get back, so the true payoff is a safer panel thats easier on the eyes when youre sliding down an ILS to minimums.

Also With This Article
Click here to view the Panel Checklist.
Click here to view “Panel Planner: Do-It-Yourself CAD.”
Click here to view Panel Addresses & Contacts.

-by Richard A. Coffey
Dick Coffey is editor and publisher of the Minnesota Flyer magazine.