In this final article of our interior renovation series, we are down (literally) to the last subject to be covered, namely carpet. Of all the major components involved in renovating interiors, the installation of carpet is the easiest. That having been said, there are still some important factors to consider.
The first is material selection. Aircraft carpeting must hold up under some very demanding conditions. As you may suspect, the owner or operator of the airplane is usually not the one who wears out the carpet; it’s maintenance personnel. For this reason I strongly believe that a tightly woven dense carpet in a mid-tone color is the material of choice. Light colors look good at delivery, but require more care and constant cleaning, and most of us just don’t have the time or inclination to keep up with that program. We have found that mid-range colors, particularly those that are woven with a subtle variegation of different yarns, hold up the best.
Wool is unquestionably the best fiber for aircraft use. It’s durable, fade resistant, and very easy to flame proof. Remember, though, too much flame proofing chemistry can cause a corrosion problem (as mentioned in an earlier article).
Here’s one final rule to consider when choosing carpet color and weave. Dark smooth carpets will readily show dust and loose stuff like grass and lint, while light colors will show soiling and dirt. So pick your poison; do you want to vacuum frequently, or shampoo? My vote is for vacuuming – it’s faster and more convenient. Pick a mid-tone multicolored carpet and you’ll do very little of either.
It’s very important to make the floor carpets easy to install and remove (we’ll show you how later in the article). You’ll find this to be quite an advantage when you take your airplane in for maintenance. An ounce of prevention is worth a pound of cure.
By now you all know my way of covering all the decisions and details of a job is to take you through it a step at a time, so let’s get started.
Aircraft carpet comes from our suppliers with all of the necessary FAA flame proofing documents. It is usually manufactured in 12’ foot widths. For an early short cabin Bonanza or Travel Air, we order a 12 x 6, or 8 square yards. A long cabin later model Bonanza F33A or Baron 55 requires a 12 x 7, or about 9⅓ square yards. An A36 or 58 Baron requires a 12 x 8, or almost 11 square yards. If throw carpets are to be made, add approximately two square yards. The above quantities will cover the floors, lower cabin side walls (kick panels), forward lower firewall and the aft bulkhead. For post-1979 A36s and 58 Barons, add an additional 1½ square yards for the aft extended baggage compartment.
First thing to do is unroll the carpet and give it a good inspection in bright light. Step back and look for color and texture irregularities. Then, verify the direction of the nap of the carpet. Carpet looms create a bias as to the way the carpet fibers stand up when they are woven. It is very important to keep this fiber “slant” running in the same direction throughout the cabin. If you were to put misaligned carpet panels next to each another, you will see what appears to be a very noticeable color difference. It’s all about the way light reflects off the carpet fibers.
To prevent this from happening, we place the uncut piece of carpet face down on the floor and mark it with lots of “V” marks pointing to what will always be forward for floor pieces and up for sidewall, bulkhead or firewall pieces.
Since the cost of this aircraft carpet is so high, we don’t want to order more than we need. That means laying out every section of carpet before the first cut is made. Keeping the orientation marks in mind, all of the old pieces taken from the airplane are carefully laid out face down on the back side of the new carpet. After some trial and error, all of the different shapes will be laid out to most efficiently fit on the new carpet.
Cutting is done in two stages depending on carpet location. Fixed side panel pieces are rigid backed, and the metal backing panels can be used as accurate templates to precisely cut the shape and size of the piece required. The main floor carpet pieces are another story. Due sometimes to a) poor initial fit at the factory, b) shrinkage with age, or c) after-market carpets currently installed, you should scrutinize the fit of the existing carpets before they are removed and mark any misfit places. Then use the old floor carpets only as rough patterns, adding about an extra inch around the perimeter of the new carpet pieces as you cut.
With the carpet pieces cut, it’s time to serge the kick panel carpet pieces and bond them to their respective aluminum backing panels with contact cement. Once carpeted, the kick panels and spar covers are installed. The floor carpets can then be positioned in the airplane and finish trimmed to precisely fit the cabin floors and accurately meet the carpeted kick panels. If you merely cut the floor carpets using the original patterns, they often won’t fit properly.
It’s best to cut the carpeting with sharp, heavy-duty industrial scissors. Razor knives are difficult to control, dull quickly, and can produce a ragged cut. Scissors allow a more precise, controlled and clean cut, especially at an inside corner where it is very critical not to overcut the edge. You’ll have a problem later as the carpet serger tries to apply the loop stitching to the ragged edge of an overcut inside corner.
I’ve mentioned serging several times, so an explanation is probably in order of what it is and how it’s done. You’ve all seen the neat, color-matched, thick-thread loop stitching that is often applied to an exposed edge of carpet. This is done with an expensive and temperamental serging machine. Of the three methods of finishing the edge of carpet, I think it’s the best for four reasons. First, with the proper machine and a skilled operator, almost any shape of carpet edge can be beautifully finished. Second, the heavy yarn used is very durable. Third, if a thread should break all you need to do is tie the loose end off on the back side of the carpet and no unraveling will occur. And fourth, no stress is put on the carpet when serging around a corner, and the corners don’t lose their shape or roll up.
We’ve tried the other two methods of carpet edge-finishing, but they really are not optimum. The first alternative method is to use leather, vinyl or cloth tape sewn to the carpet’s edge. This works, but as the materials age and shrink slightly, the carpet edges will become misshapen. The second alternative to serging is to roll the carpet’s edge under about one inch, glue it in place, and then hem it with an industrial sewing machine. This will work with thinner automotive carpet, but is not an option with the heavy carpets we use in aircraft.
For those of you doing this job yourself, just take your accurately cut carpet pieces to a commercial carpet company for the serging. The cost is $1 to $1.50 a foot for the service; it’s a good deal.
An important detail: It’s imperative that you make the emergency landing gear crank cut-out large enough so as not to interfere with the cranking process. The cut-out Beech originally made is sometimes too small and you hit your fingers as you attempt to crank the gear down while sitting in the pilot’s seat. Double-check this.
It’s now time to sew the vinyl or leather booties around the rudder pedal cutouts. Use the originals as a pattern and cut out new ones. We actually lightly glue the new booties in place to help hold them in position as they are being sewn to the new thick carpet.
We next sew the heel pads to the front carpets. Again, glue is used to temporarily hold the pads during sewing. Pads are available from automotive upholstery supply houses, and come in about twenty different colors. If a good match is not available, you can use aluminum or stainless steel to fabricate a very durable and neutral heel pad. We like to secure these metal heel pads to the carpet with short counter sunk upholstery screws and flat tinnerman nuts. Don’t screw them to the wood floorboards. After a couple of annual inspections the floorboards will begin to look like they were used for target practice.
As many of you know, Beech used snaps in older airplanes to hold the floor carpet in place. With the invention of velcro in the mid-sixties, snaps are history. However, the use of velcro comes with its own rules. First, it must be sewn, not just glued, to the carpet. No glue will permanently hold it. Second, it must be properly secured to the cabin floors, and cleanliness is the key. Thoroughly clean the surface, then apply a thin coat of contact cement as a primer and let it dry for at least an hour. I would buy only 3M self-stick velcro; we’ve experienced failures with other brands. Apply the soft or loop velcro to the floors and the hard or hook to the carpets. The hook or hard stuff will collect and retain almost any type of dirt or lint, as well as stick to clothing when you’re on the floor working under the panel, so you’re better off with the soft velcro on the floor.
Last but not least in the area of carpets is the foam backing that both insulates against sound and cold, but also helps to give the floor carpet a soft plush feel. We like to use a black closed cell (not water-absorbing) ¼” insulite foam that we buy from Skandia Inc (815-393-4600), product # IV-1. It’s light, flame proof, durable, has great sound attenuation qualities, and is easy to bond to the carpet backing with the spray-on contact cement mentioned in an earlier article. We cover the entire back of the carpet pieces with the foam to within an inch or two of the serged edges, allowing an untreated area around the perimeter for the application of the velcro.
Well, we’ve just about covered everthing related to your new interior. But before we’re finished, there’s the issue of paperwork – there’s always paperwork. The following is a breakdown of what is required for a typical interior renovation.
Logbook entry. This document details a complete description of the work performed during an interior renovation, including documentation verifying that all materials and processes conform to Federal Aviation Regulations (FARs). Every step must be spelled out in complete detail, identifying all materials, new parts installed, part numbers, reworked parts reinstalled with their work orders and FAR-conformity documents. We show here a typical logbook entry for an unmodified interior in an A36.
Flameproofing documents. There are a minimum of three documents required to verify that all interior finish materials, foam and insulation meet the FAA flame specification for use in an aircraft. 1) A packing slip or invoice identifying the material. 2) A burn certification that quantifies how the material performed during the actual burn test. 3) An 8110-3 form signed by an FAA inspector or DER who witnessed the test and who states that the material passes.
Major alteration paperwork. If a major alteration or STC’d kit was installed, an FAA form 337 and a copy of the STC must be included.
Seat belt / shoulder harness documents. There are actually three documents that verify compliance for seat belts and shoulder harnesses, both new and re-webbed. 1) An identifying packing slip or invoice. 2) A certification document signed by an FAA-licensed inspector. 3) A certification tag sewn to the belt. These tags are item specific, and must never be sewn to a different belt or harness.
Weight & balance. A new weight and balance must be calculated, and don’t leave this task to the end. There are often components that need to be weighed coming out as well as going in throughout the course of the project. The sample shown is very typical.
I always say that when the weight of the paperwork exceeds the useful load of the airplane, you’re good to go! And yet there’s more. After a little time off from writing, an FAA friend and I intend to collaborate on a Beech-specific article covering all levels of FAA approvals and paperwork, not just those related to the interior. It will be in a future issue somewhere down the road.
This pretty much wraps up (finally!) the subject of interior renovation. Cynthia and I have enjoyed writing this series and sharing some of our passion for this business. Hopefully you’re better prepared to make the right choices when you take on your own renovation. Fly safe, and enjoy these beautiful Beech airplanes!