Notes & Comments Instrumentation

From "Construction Notes" Falco Builders Letter, March 2004

From Mike Wiebe: "From the recent newsletter and the autopilot discussion: As you noted, we've now got two years flying behind the Navaid Devices single axis autopilot, which we bought from Jim Petty. I disagree with the newsletter comments on its applicability to the Falco. It works great for us and has the advantage of being simple in all respects. Jim flew it from new, and got rid of it because he was upgrading to an IFR airplane-the Navaid is a VFR-only unit. However it suits our purposes fine and installation would have been simple even if we didn't have pictures from Jim. It replaces a traditional turn coordinator, and has kind of a half-assed digital LED version of a TC built in, along with a slip-skid bubble. If anyone is interested, I'd be happy to send copies of the installation pictures and could probably even work up a couple of sketches. Buying used from Jim was an added savings. But prior to that we did talk with the company owner and found none of communication problems that you and others have had."

"Navaid has always maintained compatibility with virtually all panel mount GPS's, being able to track a flight plan (including turns), or hold a GPS heading. New Navaid units today can be bought with a device called a Smart Coupler built right in, which provides the same capability for handheld GPS's. If you get an older Navaid like ours, you can buy the Smart Coupler separately. Ours does a great job following our Garmin 295. Zero complaints, but if I was doing it again today (and didn't get a great deal on a used unit-thanks again Jim!), I agree that I would seriously consider the Tru-Trak unit. Its digital technology is leading edge, the only disadvantages being about a 25% price premium and the need for a new hole in the panel."

From "Construction Notes" Falco Builders Letter, March 2004

Duane Root asked about the pin assignments for using the RST-523 marker beacon receiver with our electrical kits. There was some confusion about what to do with two of the pins. The correct pin assignments for RST-523's P1 plug are (1) R340B-22, (2) Connect to pin 3 with a jumper wire, (3) Connect to pin 2 with a jumper wire, (4) R341-22, (5) n/c, (6) NR338B-22, (7) NR339B-22, (8) NR337B-22, (9) NR342-22. The only mystery was what to do with pin 2 and 3, and you just install a jumper wire.

From "Construction Notes" Falco Builders Letter, March 2004

Fred Doppelt reports that he has installed 'Nu-Lite' replacements for post lights. These work great and look like the light is inside the instrument. The lights cost about thirty dollars each and are available from Aircraft Spruce.

From "Construction Notes" Falco Builders Letter, September 2003

Dan Dorr asks "My manifold/fuel pressure gauge has three connections on the back. They are labeled: manifold pressure, fuel pressure, and fuel vent. The drawings show the one labeled fuel vent connected to the pitot static line. Is that the correct connection for the one labeled fuel vent?"

Yes. It's just to make sure the inside of the instrument is at the ambient air pressure.

From "Construction Notes" Falco Builders Letter, September 2003

I have been searching for years for a serviceable Century I autopilot and have decided they don't exist. Surely in that time a lot has happened to cause a re-evaluation of what's the best autopilot for the Falco. I'm thinking Digi-Trak as it seems to have been around long enough now. Is anyone flying with one. Incidentally, Aircraft Spruce are selling a new basic Century I for $2,850 US dollars.-Stephen Friend

Even though it is an old design, they are available in the US if you watch Trade-A-Plane. What I like about the design is that it is all-electric and will fly the airplane very well, even when the vacuum gauges go out. I really don't like systems that require both electric and vacuum to work since they fail you at the moment that you need them the most.

Unfortunately, I'm not up to date on the latest autopilots. Cecil Rives flew with a Century I for a while, then took it out and put in an S-Tec System 30, which is a two-axis system. Jim Petty started with a Navaid autopilot, then took it out, sold it to Mike Wiebe, and installed an S-Tec System 50, also a two-axis system. Both Cecil and Jim wrote articles that are in the Falco Skunkworks. I believe Dave Nason has an S-Tec autopilot and Fred Doppelt is now installing one.

(Incidentally, Fred was trying to buy the bracket from S-Tec that Jim Petty mentioned, but he mistook the airplane name for a part number. It was an SF.260 bracket and that's not an S-Tec part number but rather a bracket that they make for the SIAI Marchetti SF.260, the big brother to the Falco.)

David Carroll looked at the Navaid Devices autopilot, and concluded that it is "a simple, cost-effective means towards claiming your aircraft has an autopilot system. It probably works just fine most of the time intensely studied the design spent several hours talking to the owner/designer, but I walked away with a sense that it just doesn't belong in a Falco."

I have also looked at the design and talked to the designer once at Oshkosh. I explained that we sold the Falco kit and suggested that we could work together to produce an installation drawing. I was so turned off by the man, I lost interest after hearing a few sentences. I am drawn to people who are interested in quality, doing things right, talk in precise terms, and have an appreciation for all aspects of doing a proper installation. I came away with exactly the same impression that David Carroll did.

David Carroll is installing a TruTrak autopilot and he has written an article that's in the Skunkworks, and it's clearly a quality design and produced by people who are my kind of people, and who you can have some real confidence it. Tom Buttenbach has been flying with one of their systems for years and raves about it.

I would stick to a simple system that depends on electrical power only, and which doesn't fill the airplane with thirty pounds of stuff just to keep the wings level. You would be amazed at how much some autopilots weigh. The Century II and III systems are heavy, complicated systems that require both electrical and vacuum to work, and I think they should be avoided.

My conclusion is that the S-Tec and TruTrak systems are the ones you should consider, and both have been successfully installed in Falco and have pilots who rave about them.-Scoti

From "Construction Notes" Falco Builders Letter, June 1995

Stephen Friend also mentioned that the problem with his artificial horizon was that he bought it in 1992 but didn't fly it until 1995. IFR's warranty for the instrument is one year from the date on the back of the instrument, and they point out that gyros should be put on a 'scorsby' every six months until you are ready to fly the airplane. They say that any aircraft shop will have a scorsby. What happens to the gyros if you let them sit too long in one position is that the oil on the bearings drips to the bottom of the bearing. When this happens, the balls in the top of the bearing dry out.

From "Construction Notes" Falco Builders Letter, December 1995

Howard Benham reports, "Somewhere in the construction manual there is a caution about the Sigma-Tek pump, part number XXXX-006 not fitting on the IO-360-B1E. We checked this out and cannot find any reason not to use this unit. The only caution is that the pump must be installed after the engine is installed on the mount, and of course would have to be removed first if the engine is to be removed from the mount. For those of you not familiar with the Sigma-Tek design, it is the only new design in vacuum pumps in many years. It combines a new rotor design along with the new composite vane. This allows the unit to be used rotated in either direction without fear of breaking the vanes."

"Anyone contemplating installing an inverted oil system might want to consider installing the B&C VAC-2 oil pick-up unit at the same time that they install the vacuum pump as the VAC-2 replaces the existing spacer unit the vacuum pump is mounted on. The VAC-2 is designed to allow you to go inverted without the momentary loss of oil pressure that usually occurs while the upper lines fill with oil."

"You may find that the mounting bolts will need to be shortened a small amount (1/4"?) to prevent the end of the studs from hitting the housing of the vacuum pump. Also you will have to adapt a wrench to be able to tighten the bottom inside nut, but if this pump proves to be as reliable as I think it will, it will be worth the work."

Actually, the only problem we ever had with a Sigma-Tek pump was with the 160 hp I0-320-B1A, where it hit the engine mount. Dave Aronson had this problem and couldn't make the pump work. I have no idea if the current Sigma-Tek pump has the same problem.

From "Construction Notes" Falco Builders Letter, March 1994

Cecil Rives reports that Shadin is now 60 to 90 days away from shipping their new shortened version of the Miniflo fuel totalizer. The length goes down from about 8" to 4". Hans Sonntag pointed out that Aircraft Spruce carries a fuel totalizer made by Hoskins, the FT101A. I was not previously aware of this model, but it has the same functions as the other models and appears to be the right size for the Falco panel. Certainly, at 4.5" the length is right.

From "Construction Notes" Falco Builders Letter, September 1993

When you install the radio racks in the instrument panel, the normal method is to use screws and 'tric-nuts' in the flange on the back of the instrument panel. I've always heard of these things being called generically 'tric-nuts' by everyone in the business, but the other day at our local hardware store I saw that the proper brand name is 'Thread-Sert', made by Creative Engineering, of Taunton, Mass. These little babies are an expanding aluminum nut. You drill an oversized hole and then put the Thread-Sert in place and tighten up with a supplied socket-head cap screw and an Allen wrench. The two-piece aluminum nut expands, fills the hole tightly and becomes permanently installed.

From "Construction Notes" Falco Builders Letter, September 1993

Gary Montgomery and others have asked about using the Shadin Miniflo in place of the now-discontinued Silver Fuelgard. Cecil Rives has been down that road. The Shadin Miniflo is essentially identical to the Silver Fuelgard in terms of instrument hole cutout, but it's dramatically different in length. If you try to install it where the Fuelgard is shown in the drawing, the connector plug hits the fuel tank strap. Cecil says it might work if you put it where the OAT is, but even then it is probably too long. Shadin, however, is coming out with a new version that is only 4.5" long and promises to be in production in the next 3 to 4 weeks. When they do, Cecil will be trading his too-long Miniflo in for the shorter one.

From "Construction Notes" Falco Builders Letter, September 1993

It's just possible that Cecil is getting a bit over-compulsive on this one, but he asked me to pass on you to that when the autopilot cable clamps are tightened, the clamp bolts should be tightened to 55 ± 5 inch/lbs. At least that is the information the autopilot company passed on to him when he called about this. Also they said the bridle cable tension should be 17 lbs ± 2 lbs, which is an engineering-terminology way of saying that you need to remove slop from the cable or the autopilot will hunt.

From "Mailbox" Falco Builders Letter, December 1993

Incidently, I mentioned a while ago that the Shadin clearance problems can be cured with an AMP DB9S 1DC right-angle plug.

Stephen Friend
Breadalbane, Australia

From "Mailbox" Falco Builders Letter, December 1993

The avionics technician who installed my Bose system pinpointed my long-standing severe static-system leak, which turned out to be in the altimeter-the latest chapter in my epic of having bought lousy instruments. He said the instrument was at least 30 years old and obviously junk. He ordered me a new-manufacture unit and said to throw the old one out, that it wasn't even worth anything as a core to exchange.

One problem I've had for some time is a badly lagging manifold-pressure gauge. It's accurate enough, but sometimes it takes 10 or 20 seconds to respond to gross throttle movement, especially at high power settings. The problem is that the slight amount of oil that collects inside the manifold-pressure line over time. Every time I remove the panel, I blow out the line, by mouth, and can tell that there's a small amount of some kind of moisture that has collected in there. My mechanic tells me this is not an uncommon problem, and that the solution is to drill a #50 hole in the bottom of the manifold-pressure line at some low point-not necessarily the lowest-somewhere near the cylinder head. This allows the oil to drain out and doesn't affect the manifold-pressure reading.

I'm going to do so, but the problem-if anybody else has this situation-is that it requires splicing a short length of copper tubing into the Aeroquip line that we use between the engine and the firewall, since you can't drill such a hole into the rubber of the Aeroquip itself.

Stephan Wilkinson
Cornwall-on-Hudson, NY

Why not just drill the hole in the bent-tube end of the Aeroquip line?-Scoti

From "Mailbox" Falco Builders Letter, June 1993

For anyone considering-as I was-installing a Stormscope in a Falco, it probably can't be done. I had the airplane skin-mapped, and there's far too much noise-electrical energy-for the Stormscope antenna to be installed anywhere in or on the fuselage, even at the extreme tail. This is not surprising, for Stormscope dealers are warned that trying to install a Stormscope in anything like a Bellanca probably will be impossible.

The problem seems to be that the Falco's relatively long battery cable radiates a lot of electrical noise, particularly when the engine is running. It's an excellent transmission antenna.

The one place we found that might accept installation of a Stormscope antenna was the wingtips, which seem electrically quite quiet. (I should point out, though, that we tested it only with the engine at idle. It's possible that there is noise with the engine running at cruise power.) Naturally, a wingtip installation-or any other installation-would require that the strobes be off if you're using the Stormscope, but that shouldn't be a problem: if you're IFR and worried about embedded cells, you wouldn't need the strobes anyway.

Therefore, anybody who is considering even attempting a Stormscope installation should at least string a Stormscope antenna cable inside the wing during the building process. It could turn out to be pointless, at which time you can pull it out and throw it away. But there's no way to fish that cable through the same neoprene tubing, post-building, that the strobe and nav light wires run through; the Stormscope cable is pretty fat-somewhat fatter than the strobe cable.

For sale: Electric Gyro Corp. electric turn coordinator, complete with the necessary Cannon-type plug for installation. I bought it a year ago for $298 plus shipping from Aircraft Spruce, overhauled and yellow-tagged, and will sell it for $200, UPS prepaid shipping with the paperwork. It has maybe 75 hours on it, works just fine, and was removed only because I've installed a Century I autopilot, which of course has its own turn-and-bank. If you're interested, call me at (914) 534-7601 or fax (914) 534-5101.

I'm trying to get the airplane IFR-legal, rather than continuing to simply fly IFR, and I've having a terrible time getting the static system tight enough to pass the 24-month pitot-static check. The pitot system seems fine-leakage is within limits-but the static-system plumbing is way out of limits. Could you mention in the Builder Letter that I'm having this problem and would love to hear from anyone who has gone through the same procedure and found a weak point?

Steve Wilkinson
Cornwall-on-Hudson, New York

From "Construction Notes" Falco Builders Letter, June 1992

Also, when hooking up the Alcor 46150 EGT meter to the rotary switch, Cecil found that Alcor's instructions were a bit confusing. The meter has three terminals. The Yellow (+) and Red (­) are the ones we want and which are hooked up to the thermocouple leads. The other terminal is marked 'UCS' and this is only for turbine intake temperature on turbocharged airplanes.

From "Construction Notes" Falco Builders Letter, June 1992

Cecil also had a problem with the fuel flow totalizer. The Silver Fuelgard is no longer made, but Shadin makes one that fits in the same hole in the panel. The problem, though, was that the dang instrument is so long that the connector would hit the mounting strap on the front fuel tank.

The Shadin unit is about 8 inches long and Cecil and I spent some time working out how to install the thing. Cecil says that if you know about the problem in advance, you can just trade the locations with the totalizer and OAT and that will take care of the problem.

Next we considered the possibility of making up a custom plug. If you ever find yourself in a situation like this, you might try this trick. Many custom plugs are molded plastic affairs in which the plastic is simply injected around the pins and allowed to cool. You can do much the same thing to create a custom-shaped plug. What you do is first destroy the connector that you have and reduce the end of the wire to loose wires with pins on the ends of each wire. Then you put a piece of (wax?) paper on the connector on the back of the Shadin unit, and then poke each loose wire-and-pin into the proper place, shoving through the paper. The paper is there to serve as a barrier for when the plastic cools.

When you get all of the wires in place, you make a molded-in-place plug with a hot-melt glue gun, forcing the hot glue down into all the crevices and between all the wires. You can push and shove the wires over to make the plug into the shape you want. The whole process is actually rather easy, and the result it a distinctly un-lovely glop of glue, but hey, it's a neat way to solve the problem if it crops up.

In Cecil's case, that would only partially solve the problem, so we talked about mounting the instrument so that it would protrude into the cockpit and thus give him more clearance. If you're now reading this and thinking "Oh my God, do I have to go through all this just to put in a fuel totalizer", take heart. Cecil finally called the folks at Shadin, who said they were coming out with a new model in a couple of months. The new one will be 4.5" long, vs 8" on the one Cecil has. Cecil's gonna make them a deal they can't refuse.

From "Construction Notes" Falco Builders Letter, September 1992

Steve Wilkinson has been going through a debugging saga with his gyros. At first, he blamed it all on IFR, who graciously replaced his DG. The new one didn't seem to be any better, but then Steve began to think it might not be IFR's fault, because the artificial horizon was also sluggish.

Chuck Flickinger of IFR said that the problems Steve described could be in the instrument, or could be caused by a restriction in the vacuum system lines. Hmmm, Steve remembered that Jonas Dovydenas had given him a couple of plastic quick-disconnects for the vacuum system, and these had an inside diameter of 1/4".

Steve took these out and found that the artificial horizon was suddenly much better, but the precessing problems with the directional gyro continued. Then one day it began to dawn on him that the 'precessing problem' might really be a compass problem, so he checked the compass and found it was way off, and had a huge error.

After talking to some avionics people, Steve concluded that his compass problem was being caused by magnetism being generated by the CDIs of the VORs. Steve found there is something called mu metal, that you use to insulate compasses from the magnetism generated by the CDIs.

Steve writes, "I don't see how any Falco builder with an IFR kit has avoided this problem of the CDI magnets interfering with the mag compass, since Narco, at least, says you should by no means mount one of their CDIs within any less than 11 inches of the magnetic compass without insulating it with mu metal, and ours is certainly much closer than that. Can it be that nobody is bother to swing their compasses? Or that avionics shops are doing the installations and taking care to insulate the CDIs?"

"The mu metal was a bit more expensive than I'd been told: $36 for a 4" x 15" sheet. It's almost weightless, very soft and malleable-sort of like thick tinfoil. It's sticky-backed on one side, when you peel the protective paper off it, and the way you're supposed to use it is wrap one or two thicknesses right around each CDI can (which is why it comes in those odd dimensions; one sheet apparently wraps exactly around a CDI can). I, however, simply cut the sheet in half, doubled the two thicknesses and stuck them on the underside of the glareshield, between compass and CDIs."

Steve briefly reported that "It seems to have totally cured all mag-compass error." But that was before he put the #1 CDI back in, however when all of the components were back in, he said, "It's a lot better than it was, but it's still off an unacceptable amount. (The error averages seven degrees, with some cardinal headings being spot-on and others off by as much as a dozen degrees, but that's a lot better than it used to be, and at least it's useable."

"I think what I'm going to have to do is not only insulate the mag compass with the double thickness of mu metal, but wrap another piece of mu metal around the #1 CDI, which is, of course, the one closest to the magnetic compass. I wonder if the problem I'm having is due to the fact that the more expensive King CDIs with rectilinear needle movements (as opposed to the typical "windshield-wiper" needle movement), like mine, have bigger magnets. And that a CDI that includes a glideslope, like my #1, has a second set of magnets. I don't know why I should be having this problem and nobody else has noticed it."

From "Construction Notes" Falco Builders Letter, September 1992

Steve has a manifold pressure backup system for his vacuum system, and I noticed that the large plastic hose that goes to it was partly flattened where it took a slightly too-tight turn. He's since straightened that section out. Things are better now, but Steve's not yet through his little battle. The other day, on the way back from a trip, the DG suddenly switched about 45 degrees in level flight.

After writing all of the above, I finally took a look at the instruction sheet that came with the mu metal. It was pretty clear to me that Steve hadn't installed it according to their instructions. I don't know beans about magnetism, but their instructions say to wrap the 'can' of the CDI completely and that the mu metal foil must overlap. It appears to me that this is not a line-of-sight phenomenon. Steve concedes the point and will try it that way.

On that trip, Steve flew for about 45 minutes in heavy rain and his NorthStar loran worked beautifully through it all. Lorans are notoriously susceptible to precipitation static, but there seemed to be none. He called NorthStar and asked them if possibly the fact that the Falco was wood, had an internal ground plane and other factors specific to the Falco might mean that his Falco was permanently immune from the normal P-static problems associated with lorans. NorthStar didn't know for sure, but they said it "could be."

From "Construction Notes" Falco Builders Letter, March 1991

Steve Wilkinson is rapidly approaching the completion of his Falco and even threatens to take it to the airport shortly. Lately he's been hooking up his avionics and send along this note:

"Something you might be interested in, since the instrument-panel drawing mentions the clearance problem that exists if you use the various King VOR heads that have a converter as part of the box rather than within the navcom itself: I bought one KX-165 and one KX-155, and with the 155's VOR head there is indeed such interference, but there seems to me to be an easy way to fix it. I think a lot of Falco builders will opt for the 155s, since they're considerably cheaper and since the 165 offers very little extra for the money. (I bought one so I could wire my Northstar Loran directly into the CDI, which you can't do with a CDI that has an internal converter.)

"I asked the shop that sold me the radios (Gulf Coast Avionics) to make up the harnesses with "right-angle connectors" or some other sort of space-saving plug at the back of the VOR head, but they'd never heard of any such thing and made up the harnesses conventionally.

"I measure 210mm clearance between the aft face of the panel and the rear of the fuel tank, based on the tank-installation drawing. However, the plug itself is a good 60mm in depth, and if you take the metal jacket off the plug, the internal part of the plug is only about 30mm long. I simply took the soft metal jacket off the plug body and cut it to remove it from the made-up harness, and now the VOR head, converter and plug are only about 190mm long.

"The only disadvantage of doing this is that the mechanism that clamps the external male part of the plug to the fixed female part gets discarded if you remove the plug shell. But there are plenty of ways of solving this, including inelegantly taping the two plug halves together with electrical tape, and I think it's infinitely easier than locating whatever a "right-angle plug" is and making up a new harness, if your KX-155 comes with a conventional harness."-Steve Wilkinson

An electrical engineer friend of mine says that he's had great success at making 'short' connectors by completely discarding all of the protective shell and then using a hot-melt glue gun to squirt glue down between all of the wires and then mold the whole thing into the shape he was after. (In fact, he said in one dire-straits situation he actually made an entire 'connector' with nothing more than pin-ended wires by putting a piece of paper over the receptacle, shoving the pins through the paper and into the receptacle and then squirting hot-melt over everything to make a single molded connector of hot-melt.) You can also use silicone rubber RTV for the same purpose, but the nice thing about hot-melt is that the whole process is over in five minutes. God help you if you ever have to take it apart.

Steve Wilkinson also said that the topmost radio hits the diagonal frame No. 2, and that it requires taking a chunk about the size of a sugar cube out of the frame, and that until you do, you can't for the life of you figure out why the panel suddenly won't slide all the way home. He says "it feels like the radios are hitting the tank, but of course they aren't. Then you finally notice the interference, after hours of fiddling." Steve said that the interference that he encountered was only about 3/4" and that you only need to take that amount off the aft face of the frame-instead of cutting all the way through the frame.

From "Construction Notes" Falco Builders Letter, September 1991

Occasionally builders ask us how we get the lettering on our instrument panel, either to add more custom lettering to a kit-built airplane or to make a panel from scratch. The instrument panel display we take to Oshkosh is always a big hit, and you'd be amazed how many Glasair/Lancair/RV6 builders take pictures and make notes.

To begin with, our panel is made of painted aluminum. While black is a traditional color for people with no imagination, the dark gray panels used on corporate jets are much more attractive, and they make for a very professional-looking panel. When I first designed the panel, I researched a variety of gray paints to find one that looked just-right. I found the perfect color in Pactra 20017 Asphalt, a flat dark gray with a hint on blue in it. Unfortunately, when I sprayed a protective coating over the paint, it became almost black.

Recently, I've been fixing up the panel of the Corporate Disgrace, and I went looking for a paint. My local model airplane store no longer carries Pactra paints, but I found a Testors paint that is the same color; it's Testors P/N 1960 Panzer Gray, and Testors has a neat system of giving the Federal Standard color numbers for the paint. Panzer Gray is FS 36076, so if you want that color in the paint of your choice, just take that number down to your local paint store and ask them to mix some up.

My panel had been painted in shiny black, so the first thing I did was to sandblast it all off. Then I used a light coat of automotive sanding lacquer primer-because if I understand things right, you should always use a primer for good adhesion. Then I sprayed the Panzer Gray.

The lettering that we use is simply rub-on lettering which you can buy in any art store. It comes in various colors (we use white), but the problem with using standard lettering is that you can never get the characters lined up properly. So we get custom Letraset lettering done for us. We simply had the type set, did a paste-up of all the artwork and sent it off to Letraset to produce the sheets that we include in our kits.

Letraset has a minimum order of 50 sheets, so this is not practical for an individual builder, but there is a way to get this done. The first thing you do is to get your hands on a Macintosh computer and type out all the lettering in the type face of your choice. I used our CAD system to draw all the lines, circles and arcs I needed. (By the way, for switches, circuit breakers and the like, we include an alignment circle at each hole in the panel in the artwork. It costs nothing to do this, and it makes aligning the lettering a snap.)

Any large city will have 'stat' houses, which specialize in camera work for advertising agencies and printing firms. They produce stats and many other forms of art reproduction used in the layout of advertisments-for our newsletter photos, for example, we use 85-line-screen, half-tone position prints with the picture reduced or enlarged as needed, paste them on the page and then just xerox that sucker.

One specialized product that a 'stat' house can produce is a Chromatec "INT" dry transfer, which is available any PMS color you want and also metallics. It's really just a custom photographic process that converts your artwork into rub-on artwork. Artists use this type of thing all the time. For example, when Lu Matthews was doing the air-brush illustrations of our paint schemes, there was no way to do the Sequoia logo or lettering by hand. So he just had the type set in a larger size, shot our logo down and then had dry transfers done.

So that's all you do, just lay out your artwork, get a custom dry transfer done (it'll cost about $30.00 per letter-size page), and rub the stuff on your panel.

The last step is to spray a clear protective coat over the lettering. You have to be careful to test this coating to make sure it won't attack the paint or lettering-more than one Falco builder has watched in anguish as the paint and lettering curled up. Letraset makes a product called Matte which is a sprayable protective coating for their lettering.

I decided to experiment and tried Letraset Matte and Testors P/N 1960 clear flat lacquer. Maybe it was an unfair test because the Letraset can was a number of years old, but in any event the Letraset was noticeably yellow, while the Testors was not. I used the Testors product and found to my surprise that it did not darken the paint on the panel. Since it's a lacquer, you should just fog on a very thin coat, let it dry and then fog on a few more very light coats-this is because lacquers have a tendency to attack enamels. All clear coatings will yellow with age, and the thinner the coating, the less yellowing you will see.

From "Construction Notes" Falco Builders Letter, September 1991

If you are installing a Davtron clock in your panel, you'll notice that they have a keep-alive battery that's attached to the clock. This has to be replaced every two years or so. Problem is that the battery is something you have to send off to Davtron for. They put some batteries together, solder leads to them, and then install the battery in heatshrink tubing for a nice, tidy affair.

It isn't the cost of the battery ($8.00) that I object to, but rather the necessity to pull the panel out, figure out what I need, call Davtron and then wait for the thing to arrive. Karl Hansen had mentioned that you can make up your own battery from Radio Shack parts, so I called Davtron and asked them how to do it. They were very nice, and explained that for my clock, you just need to put four AA batteries in series. Radio Shack sells a little battery holder plus leads that you can clip the thing on with. I made the switch, and now when I need to change the batteries, it's no big deal, and if I need to steal some batteries for a flashlight, they're right there.

From "Construction Notes" Falco Builders Letter, September 1991

I get questions about what to use instead of the Silver Fuelgard, which has been discontinued. As far as I know, there are two other models which come in the same size instrument, the Shadin Miniflow and the Alcor TruFlow. The Shadin instrument is available with a loran interface, dunno about the Alcor. Other than that, I think the features are essentially the same-both use the same fuel flow transducer, so there can't be any difference in the accuracy.

From "Mailbox" Falco Builders Letter, December 1991

Interested in your Construction Notes piece about panel placarding in September's newsletter, specifically your remarks about protective coating. I've been fooling with model aeroplanes since I was a kid, and when time permits I'm heavily into small-scale static model building, matching FS numbers and all that stuff. As you say, you have to be careful what kind of clear coatings you use over enamels-the more so with the ultra-thin waterslide decals used on small models.

The best (if unlikely) product I've ever come across is Johnson's 'Clear' floor polish (I think it is marketed under the 'Future' brand name in the USA). It seems to be compatible with just about any kind of base coat, even metallics which are easily softened by most clear coat oversprays. It brushes on even over a high gloss airbrushed finish with nary a trace of a brush mark (though you can spray it, but be careful if the base paint is a high gloss or highly impervious or it'll pool or run) and provides a very effective barrier against whatever you susequently apply. In fact, for gloss finishes there's no need to do anything further, though you'd obviously want a non-glare finish on a panel. I've seen little evidence that it yellows perceptibly, either. I have a couple of Clear/Future-coated all-white models (the worst!) that are still virginal after about eight years of daylight exposure in a glass-fronted case.

Incidently, regarding color changes with lacquer coats, I've found that flat coats invariably lighten the appearance of a colour to the eye, gloss coats darken it, particularly when applied over a finish that started off flat.

Luv that Passenger Warning placard on the Corporate Disgrace!

Mike Jerram

From "Construction Notes" Falco Builders Letter, June 1990

Stelio Wilkinson noted that Piper recently issued a service bulletin regarding the fact that the 90° fitting leading from the block to the oil-pressure transducer hose on certain Tomahawk Lycomings was "not of the restrictive type" and that it should be replaced with one that is designed to prevent catastrophic loss of oil in case of a transducer-plumbing failure. He wanted to know if we should do the same.

That was a new one on me so I asked Frank Christensen about what they do out at Christen Industries. Frank said that on the Eagle kits, they do not use a restrictor fitting, but on all production aircraft they use a restrictor fitting as a matter of policy. It is a practice that was started years ago on the Pitts and was adopted so long ago that he doesn't have the foggiest notion what sort of reasoning that went into this practice. All they do is press an aluminum plug into the fitting and then drill a 1/32"Ø hole in the plug.

From "Construction Notes" Falco Builders Letter, December 1990

Joel Shankle discovered a little problem with his fuel gauges. They work fine, but when you cut on the panel lights, the needles move very slightly and show less fuel. The problem was traced to a marginal ground between the engine instrument cluster's case and the instrument panel. Because of the paint on the instrument panel, there is an incomplete contact between the mounting screws and the panel. If you ground the case of the instrument cluster with a wire, the problem disappears, so that's what we think all of you should do.

From "Construction Notes" Falco Builders Letter, September 1989

Jim Petty reports that a model train paint, Floquil "Reefer Gray", is a beautiful slate-gray paint for the instrument panel. Their sealer, however, is not so good. It turned Jim's panel yellow, although it dried clear in his tests.

From "Construction Notes" Falco Builders Letter, September 1987

I'm often asked about using an HSI in the Falco. They are wonderful devices and a natural for our space-limited panel, but I have always advised against it. Most HSI are too long and will not fit. Second, none of the normal general-aviation HSI's stand up to acrobatics. Even King Radio salesmen advise against putting an HSI in the Falco-they have problems enough from the straight-and-level gang.

There is one HSI which will take the abuse, the Collins PN101. In the earliest versions, there was an excessive array of remote black boxes and power supplies. In later versions, the remote boxes have been reduced to a mininum. There are a lot of these installed in SF.260s, and they do stand up to acrobatics. The only unanswered question is the length-we still don't know if they will fit. These things aren't cheap -best price around is $4,995.00 from American Avionics, 7675 Perimeter Road South, Boeing Field, Seattle, Washington 98108. Telephone (206) 767-9781. Richard Clements has been looking long and hard at this. If anyone orders the installation instructions and drawings, get me an extra copy to check things out.

From "Construction Notes" Falco Builders Letter, September 1987

In our plans we specify a pitot tube sold by Instruments and Flight Research. This pitot tube is made with a Nylo-Seal fitting so it is perfect for the plastic tube we use. This pitot tube is no longer available. From what I can tell, the pitot tube was a Cessna part, and I don't know if IFR made them or bought them.

If we can't get the Cessna model, then we might as well change our ways and adapt. The industry-standard "mil-spec" pitot tube you have seen advertised in catalogues is the AN5812. It has a 3/16" tube about an eighth of an inch from the front of the top of the part and a brazed-on AN786-1 fitting at the top of the tube. This has 7/16-20 threads for a 1/4" flared tube -useless for polyethylene tubing. Just aft of the tube is a strange-looking electrical connector, an AN3115-1 bayonet connector-a depression-era labor-intensive WPA design if I ever saw one. If it were not for the difficulty in changing the mil-spec drawings, this would long ago have been changed to a more modern design.

But the Mayan toaster cord plug is still an acceptable connector. Two pins protrude from the top of the pitot tube. The sockets are brass, and you strip the wire and solder it in place. The sockets are intricately machined pieces which are cross-sawed to give them some springing action and a machined inner depression matches a ridge on the pins. The two sockets are loosely held in place by two plastic pieces which make up the housing. Simple to install, easy to attach and if you pinch the sockets closed, the connection is very good.

The problem for the builder is when he or she interfaces it-now we're back to modern times!-with the plastic tube. I can't figure out any way of attaching the plastic tube to the flared-tube fitting without using an excessive number of conversion fittings-none of which will fit between the plug and the pitot tube mast. It appears that the simplest solution is to order the pitot tube without the fitting and just shove the plastic tube over the 3/16" copper tube. That's what Piper does. I've tried it with a piece of Poly-Flo tubing, and it's a good, tight fit.

You can order these from any catalogue house and cut the fitting off with a hacksaw, or you can get yours direct from the factory without the fitting. The pitot tube is made by the small Ohio firm of Aero Instrument Co. My kind of company-they don't do anything but make pitot tubes and the president is the one who answers the phone. We have a new entry from them in the price list.

From "Construction Notes" Falco Builders Letter, September 1987

Instruments and Flight Research continues to be the slowest bunch I've ever run into. The quality of the instruments is fine, but Pawel Kwiecinski has managed to build a Falco in twice the time it has taken them to deliver his instrument order. They also have a infuriating habit of sending us price increase notices one week after we send out our builder letter. Please be advised that their electric clock is just a little clock with hands that go round. It is not the Davtron digital clock-timer shown on the instrument panel drawing.

From "Construction Notes" Falco Builders Letter, December 2000

I had been toying with the idea of installing an S-TEC System 30 Autopilot in my Falco for some time. Cecil Rives' article on his installation gave me the push I needed to go ahead and do it. My experience was much the same as Cecil's, but I have a couple of additional observations:

1. As Cecil said, both the roll and pitch polarity are backwards for the Falco, and may be corrected by reversing the wires to the servo motors. It is also necessary to reverse the "UP LED" and "DOWN LED" wires, to make the required trim indication correct.

2. It is not necessary to move the panel forward in order for the Turn Coordinator/Roll Computer to fit. Simply removing the connector shell leaves plenty of room. This defeats the connector locking mechanism, but the connector can easily be safety wired in place. I suspect his panel was moved to accomodate the S-TEC Directional Gyro, which I did not use.

Being able to fly completely hands off while looking at a map, finding things, etc. is a real luxury. The altitude hold function is one more step in reducing IFR pilot workload, and is a valuable addition, in my opinion.

Kim L. Mitchell

From "Construction Notes" Falco Builders Letter, June 2002

Please bear with me whilst I ask a really basic question in regards to fuel pressure. Various people from Stephen Friend to LAME to engine workshops have given me conflicting answers to the following question: Where should the fuel pressure gauge read from? That is, should it be from the gauge port on the spider, or should it be from between the engine fuel pump and the FCU?

We started out from the spider and got a very low reading of 2 psi. The LAME disagreed with this and wanted to plumb it into the fuel pump line. This we did and recorded 30 psi on a test gauge. We also recorded 30 psi direct from the electric fuel pump. As you are aware, the combined manifold pressure/fuel pressure gauge red-lines at 7 psi or thereabouts, which is obviously useless for 30 psi. Our LAME was questioning whether we had the wrong gauge for our engine (IO-360-B1E), but Stephen feels sure that we should be reading it from the spider. Could you please clarify?

Drew Done

Both parties are correct in the sense that both methods can be used in an aircraft, but it's a design decision on how you do it, and there are merits to both methods. In our design, the fuel pressure is taken from the injector spider and the gauge is designed to read the pressures that you find at the spider.

From "Construction Notes" Falco Builders Letter, September 2002

I would like to pass on a technical problem to the other Falco flyers. I have had a couple of problems with the manifold/fuel pressure gauge that Sequoia furnished in the instrument kit. The first is when I installed the gauge the manifold pressure side worked fine for the first 25 hours of flying then it would only indicate atmospheric pressure and not change the pressure reading even at a closed throttle setting. I flew several hours using no gauge at all. I pulled the gauge and returned it to Sequoia Aircraft to have it repaired. The gauge is from United Instruments, and we both thought it was still under warranty. It was not! The warranty was from the date of manufacture and not the date of installation. Something to think about.

Their repair facility said there was nothing wrong with the gauge except that the manifold gauge dampener screw was too tight and that might have caused the gauge to stick. With our move to Missouri, I needed to fly the Falco back to our new home state. In order to have a manifold/fuel pressure gauge for the flight back I purchased an overhauled gauge because the repair shop could not return the gauge in time for the flight. The overhauled gauge has worked fine and when I can I will put the original gauge back in to see if it does work.

The second problem is that the fuel pressure side of the gauge would indicate off the scale at full throttle. The gauge was plumbed as per the Falco plans with the feed line coming from the fuel flow divider from the fitting hole that is marked "Gauge" and the vent line going to the tee from the static port lines. The gauge seems to be indicating double the amount of pressure that it should be indicating. I was told by the engine rebuilder that the fuel pressure at the 'spider' should be between 5 and 7 pounds psi and that the engine could not run at a pressure that was that high. Sorry, but the engine does run fine and at all throttle settings

Thinking that the gauge was at fault, I checked the fuel pressure with a certified gauge from my local FBO. That gauge read 17 psi at full throttle also which is the same as the original gauge. The interim overhauled gauge indicates the same higher pressure. Back to the drawing board.

If anyone has had a similar experience with an errant fuel pressure gauge and found a fix to the problem please let me and Sequoia know.

Bob Brantley

This has been a frustrating thing for both of us, and we've been caught between a Falco builder and a manufacturer. United Instruments said they put the instrument on a bench, found it worked fine, adjusted one screw and recertified the instrument. Thus, because there was nothing wrong with it at all in their view, it was perfectly good instrument that was returned to them for no reason that they could see and warranties did not even enter into it.

My theory is that there is some material loose inside the instrument that causes the 'venting' side of the instrument mechanism not to work, and that this is the root cause of the problem. Until it's found and diagnosed, there is no way to know what went wrong, so United Instruments could be right that the instrument is just fine, and the problem may well appear again when the instrument is returned to the airplane. Stuff happens.

In our last newsletter, we had a long report from Bob Brantley about his problems with his manifold/fuel pressure gauge. Drew Done sent us this report:

I thought that I would send a quick note to you in response to Bob Brantley's comments/problems in the latest FBL. I have had exactly the same problems.

First, my manifold pressure gauge read perfectly-from idle to full throttle the indicator needle was smooth and positive. When the engine was shut down, the needle would return to atmospheric pressure immediately. After about 45 hours, the needle response became slower and slower to the point that I wasn't using the gauge at all and was using fuel pressure and fuel flow as my indication.

On pulling the gauge out we thought we found a tiny piece of rubbish behind the dampener screw. After bench testing the unit I reinstalled it just to find that with the engine running that the needle was going to vibrate itself to pieces. So out again and back to the instrument shop. With a small amount of tightening of the dampener screw everything was fine for about another four to five hours, then the whole process started to slow down again. By this time I was getting rather sick of pulling the panel around to get the gauge out, to say the least.

The long and the short of the saga is, I hope, that the dampening screw is very slowly vibrating itself in tighter till it blocks the air flow completely. When I last pulled the gauge out the needle was stuck on 23".

The solution was to again thoroughly clean the inside and then put a couple of drops of thread holding Loctite 222 on the dampening screw thread, tighten it, test for response, back off a quarter of a turn at a time till the response is right but not too sensitive.

We did this about 10­12 hours ago and so far everything is fine and hopefully will stay that way. At least it has taught me how to get the gauge out without moving the panel forward at all.

Bob's second problem of the fuel pressure gauge indicating off the scale at full throttle is exactly the same as mine. I plumbed the gauge as per the drawings to the fuel flow divider and on takeoff the needle is well passed the markings of maximum pressure, but as soon as I pull the power back to 25" the fuel pressure needle comes back to around four psi. Seeing as everything settles down quickly and that my LAME isn't worried about it, I have decided not to worry too much about it either. If we are totally wrong with these assumptions, somebody please let me know.

VH-DJD now has 67 hours on the clock all of which have been fantastic fun. We are consistently showing a TAS of 176 to 178 knots at 7500 feet. Two more knots would be great for it would make the math easier, but I'm just being picky. If there is anyone out there who needs a hand making some ribs or whatever give me a call, my workshop looks rather empty at present, and I hate TV.

Drew Done

It's good to know that I'm not the only one with that problem, misery loves company sort of thing.

With 44.5 hours now the reinstalled gauge is still working fine and with the new fuel gauge plumbing setup so is the fuel pressure gauge.

I have been fitting the main landing gear doors and have finished making the final trim tabs. Plan to have the trim stripes painted early next year. If all goes as planned will see you all in Oshkosh.

Bob Brantley

From "Construction Notes" Falco Builders Letter, September 2001

David Carroll asks about the speeds for an airspeed indicator, as he is getting a true airspeed ASI made. For our instruments, we have a stepped white arc for flaps at 53 to 87 kts (flaps full) and 53 to 97.5 kts (flaps 20°). Green arc is 65 to 161 kts. Yellow arc is 161 to 208.5 kts. Red line is 208.5 kts. We also mark our gauges for maneuvering speed, acrobatic, at 135 kts, maneuvering speed, utility at 122 kts, and gear speed at 108.5 kts.

From "Construction Notes" Falco Builders Letter, September 2001

John Oliver reports a problem with the oil temperature gauges reading too high. The problem started after an engine tear-down following a gear-up landing. He replaced the oil temperature sender and it had no effect. John checked the ground of the sender to the engine and that was fine. Attempting to locate the problem, he flew the Falco at 3000 feet, and with a normal power setting, the oil temperature indicated above red line (John thinks that the oil temperature is normal and that the indication alone is wrong). After landing, and with the engine off, but still hot, he turned on the master switch. The oil temperature indicated about about 30% of the green arc, but when he turned on the alternator switch, the oil temperature jumped about 40%.

The only person I know to call in a situation like this is my genius friend, Walter Marsh, who thought about it for a moment and concluded that it sounds like the negative side of the alternator is not getting grounded to the engine and back to the battery. With the master and alternator switches on and with the engine off, he said to meter-test for voltage between the alternator case and the engine, and also between the engine case and the negative terminal of the battery. If they are properly grounded, then there should be no voltage.

From "Construction Notes" Falco Builders Letter, December 2001

Glyn Russell's artificial horizon died on him, and he went looking for a new supplier. He dealt with Aircraft Quality Instruments, 2649 S. Custer, Wichita, KS 67217. They are a rebuilder and they charge $225.00 per instrument to do the rebuilding. Glyn asks that we pass along this information to other Falco builders who might neeed help with instruments.

From "Construction Notes" Falco Builders Letter, March/June 2002

The alternator analyser thingy. How does it function? It has a green section marked good and a red one, bad. There is also a thin red band at the start of the green, bad too I assume. Does this just mean there is something wrong with the alternator or is there a specific fault it is signaling?

George Richards

George is working with Giovanni Nustrini, who now owns the Falco that Syd Jensen built. This has an alternator analyzer installed. The alternator analyzer was a great idea, but it never caught on. It measured ripple-current. The theory is that alternators don't fail suddenly as is commonly thought. They have three field coils with the associated semiconductor devices. When one of the three drops out because of the failure of a semiconductor device, then the other two start to work harder to keep the voltage where it should be, the thing heats up and then the entire thing fails. With an alternator analyzer, you can see that you are in trouble, so you can reduce the electrical load.

The device is no longer made. It was once offered at a reasonable price but then the price when up to $300.00 or so on special order only, and nobody bought it any more. Somewhere deep in my files, I have a schematic for a home-brew version. It was published in Sport Aviation.

From "Construction Notes" Falco Builders Letter, March 2003

What are your thoughts on using electric gyros?  Seems to me, electric gyros were prohibitively expensive, but now that vacuum system component prices have skyrocketed, cost is no longer an issue and gains can be made in reliability, simplicity, and weight savings.  From a certification standpoint, would an alternate power source satisfy the FAR?

Bill Nutt

I'm not sure about this. I've always understood that the value of the dual system was that if the electrical system failed, then the vacuum system would keep on going. I'm sure there's nothing wrong with the idea of an alternate power source but, of course, it has to be designed and installed properly.