Electrical/Wiring Construction
Electrical/Wiring Construction |
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Date: December 2002 |
Chapter: 13.0 Electrical |
Section: Fuselage |
The Comm antennas are installed by the factory in the Fast Build Wings.
The Nav antennas are installed by the factory in the Fast Build Wings.
We order material from RST Engineering to make our Glideslope antenna. Here's a picture of my efforts...
Glideslope Antenna
Ditto our Marker Beacon antenna....
Marker Beacon Antenna
Here I purchased a standard transponder antenna from Spruce, and installed in underneath the gear legs were it will be almost never seen, and not fry any of my loved-ones....
Transponder Antenna
Transponder Antenna Installed
We will not install a Loran antenna or receiver.
We expect that the GPS antenna will come with our MFD, and can be mounted in the cabin, or onto a shelf that I've built on top of the landing light housing.
update, our primary GPS came with the Blue Mountain E/1, we expect we'll have another one once we buy a WAAS approved GPS/COMM later (the 430 or 480 by Garmin). Right now these are mounted on top of the nose mounted landing light.
The ELT will have it's own antenna. We're looking for the new satellite/GPS compatible system that operate on all three frequencies (121.5/243/406MHz). We will mount the unit on the center spar, as this is the area most likely to remain intact in our opinion, should we land off-field.
Not yet complete, though here's the preliminary layout. Also, here's a picture of us fitting the panel and glare shield with some cut-outs of some of our instruments on the panel.
Panel Test Fitting
One of the first things that we needed to do on the instrument panel was to create permanently mounted panel sections on both ends of the panel for the engine, propeller, and mixture controls. The panel was first cut to accomodate the vernier controls, and then a connecting flange was laid up from triax and nutplates were installed to make it one integral unit once installed. See Section 17.2.2 for more about the engine controls.
Instrument Panel Cut-Line and Screws
Forming Instrument Panel Flanges
Throttle / Propeller / Mixture Controls Installed
Laying Out the Instruments
We've decided to use Honeywell Microswitches as our annunciators. We got these from FMW Distributors, whom we highly recommend. Their service was excellent, and we're very pleased with these units.
Annunciator Testing
Here the annunciator is tested after routing all of the push-to-test lines to the testing relay, all of which were routed through rectifier diodes so that they do not back-feed each other.
Push-to-Test Button in Operation
Blue Mountain EFIS/One Delivery
This is the first bench test of the EFIS/One, since we don't have the screens yet (backordered) I'm using a flat panel LCD monitor that I have to test with. Here you can clearly see our "Canard" airplane icon on the moving map, and I68, our home airport just off to the northwest of the house. You too can have one of these, see Blue Mountain.
EFIS/One Bench Test
Well, sports fans, now that we have the EFIS, the panel layout is changing a bit. Things are never quite the size that you think that they are, and have requirements that you just didn't quite see from afar. As you can see from the next series of pictures, I've taken a new factory panel and made new cut lines on the sides for the stationary portions (with the pilot and copilot engine controls) and pilot side fresh air duct. Then the EFIS screens take up a majority of the rest of the panel. The backup EFIS lite, also from Blue Mountain, will now be mounted near the center of the panel as it's pretty deep and wouldn't fit easily anywhere else. Also, the backup, external, CDI (Course Deviation Indicator) will mount above that, then the clock and external (from the EFIS) fuel indicator. The annunciator lights are mounted directly above the EFIS, and the roll trim indicator and dimmers are located just below.
Bench Testing Fitted Panel
Close-Up of Panel
Here I'm installing the new GRT Sport EFIS as our backup/secondary display unit. My buddy Carlos works at GRT, and they were able to hook me up with a unit super fast so we could install it this week, and fly to Dallas to continue our flight testing with Dave Bertram down there. Unfortunatley we didn't get our ferry permit to take her to Dallas, but the GRT looks sweet, eh?
Installing in CoPilot Panel
Mounted in Panel
From Pilot Side
Booting Up
Instrument Panel Overlay
The last picture above shows the overlay that we've made to glue leather to, it will cover all our scew holes and just allow the instruments to poke through, in the interior gray color.
We've also been installing a backup battery for the EFIS to keep it up and running while the starting is drawing the primary battery down. This would also supply the EFIS for some time should the dual alternators and primary battery fail. The battery had to have a tray fitted to restrain it, and then an diode was installed so that only the EFIS can be fed from this battery.
Making a Diode Mount
Pulling batter out of tray layup
Battery Tray
Finished Tray
Yet another change. After mounting the EFIS screen on the copilot side, it became obvious that the radios were going to interfere with the screen. We've decided to change the layout yet again, swapping the EFIS/Lite for the larger and more capable EFIS/Sport from Blue Mountain, and placing this on the copilot side of the instrument panel.
Here is the mounting frame for the EFIS/One flight computer, mounted level fore-and-aft and side-to-side, and inline with the flight path. I've used square tube stock and drilled and tapped mounting holes, the created angle aluminum mounts off of the keel and the pilot side of the fuselage to attach the tube too. As you can see below, it's a very tight fit after leaving room for the screen to mount behind the panel., but the canard does barely clear.
EFIS Bar Mounting
EFIS Bar Mounting
EFIS/One Mounted with Canard
EFIS/One Mounted, from above
Here is a shot of the panel after the screen and EFIS computer have been wired into the aircraft's electrical system.
EFIS/One on Aircraft Power
Compass installed
Yet another change. The magnetometer is moving again, it started on top of the landing light, but the light had a steel back-shell. Then it went onto the top of the canard, but the offset torque tube and the EFIS display case are steel, so it had to move. I decided to put it in the strake outboard area, so we pulled the wings back off. What a hassle. I built a 0-incidence base for both sides, as I'll be installing a backup EFIS later, and it'll need a mag as well. See also below where we moved the compass to overhead. This is sub-optimal, as it's hard to read here, but at least it's in the plane if needed, I don't expect to use it much.
Magnetometer Base
Magnetometer installed
Overhead mount
Much better
We've ordered our engine instruments from Blue Mountain to mate up with our EFIS/One.
One thing that decided to add was a ground power plug for charging the battery, jump-starting the engine, and/or running the (all-electric) avionics on the ground (such as for testing). I bought the standard 3-prong style plug from Aircraft Spruce with the hinged cover, and glassed it into the nose of the fuselage in front of the canard. This keeps the plug in easy reach, far away from the prop, and puts the ground personnel within sight of the cockpit.
Ground Power Plug
Here is the basic electrical (power and ground distribution) system (as diagramed at top of this chapter). First thing was to install the Ground Power and Master Solenoids, which both are rated for continuous duty, the instrument grounding block, and the battery. The master turns on the electrical power for the entire aircraft, except for the battery bus. The Battery Bus has one side of the electronic ignition system for the motor (in case we have an in-flight emergency requiring shutting the master off), the dome light, and the engine hour (Hobbs) meter.
Ground Power is pilot controlled, with a press to test button/light verifying that power is connected to the receptacle and is of the proper polarity. If so, closing a switch breaker allows all aircraft systems to be run off of the external power, the battery to be charged, or the engine to be jump-started.
Master and Ground Power Contactors
Battery Installed
Instrument Grounding Block
Firewall Ground - Fore Side
Firewall Ground - Aft Side / Starter Contactor
Main Power Fuse Blocks
Battery Bus Fuse Block
A relay box was created to handle two functions. First I didn't want any high current in the overhead switch panel in the cockpit, so any high current application will be controlled by a relay where the switch only handles the low current in the cabin that drives the relay coil. Secondly, there are a couple of applications where we need to reverse the wiring, for the speed brake and pitch trim actuators, and we use relays for this application using both normally open and normally closed contactors. The relays are mounted all together in the nose of the airplane in quick-removal plugs for ease of maintenance. Also, the relay box itself was built with DB25 computer style connectors for quick installation or removal.
Building Relay Box
Installing Relays
Continuing the electrical system installation, I've setup the Essential Bus diodes, seen in this first picture with the green leads. This will feed the avionics under normal circumstances from the main power bus, but is capable of being back fed from the the battery bus by switch on a switch-breaker on the instrument panel. This will allow the (all-electric!!) instrument panel to maintain basic flying requirements with the master off, in case of an in-flight emergency (electrical fire or alternator failure). The battery will happily support the Blue Mountain and the electronic ignition for more than an hour while a precautionary landing is made (not to mention the backup alternator installed on the vacuum pad). The diodes prevent the rest of the electrical system from being powered in this back-feed situation. Also note the many fuses that have been installed to support the operation systems, and the large cannon plug that will connect to the instrument panel. This will allow for the easy removal of both the panel and the canard wing.
Contactors on Left, Essential Bus Diodes, and Battery Bus Fuses
Wiring - Instrument Ground Above, Main Fuse Bus Near, Panel Plug on Top
The Speed Brake warning light in the annunciator panel will be driven by this limit switch. It will light a Yellow "Speedbrake Deployed" light whenever the brake is not completely retracted. The brake itself is driven by the toggle switch on the joystick pictured in the next section. The center position is a dead (no change) position. Down is a momentary switch which will deploy the brake while held down. Up is a static position that will retract the brake completely (it has it's own internal limit switches to control the actuator's maximum travel). This is handy in that you can get as much down travel as you want/need, but if you're going to abort a landing you can just flip the toggle and know the brake is coming all the way up.
Speed Brake Limit Switch and Bracket
Speed Brake Limit Switch Installed
Many of our switches are going to be on the overhead panel or on the stick grip. We elected to get the Infinity Aerospace grip, with a two axis top hat for elevator and aileron trim, a push-to-talk button, a radio (Com1/Com2) flip flop, a speed brake toggle, a autopilot disengage, and a PFD screen switch button.
Infinity Stick Grip
The next customization we undertook was to install a dome lighting system with a 'theater light' fade-to-black feature with VW Jetta dome lights, outlined in Section 13.3.3 and Section 15.2.4.
Here's a couple of shots of the overhead switch panel that we had made by Superior Panel Technology (http://www.sptpanel.com/). I like this setup much better than having all of these on the main panel. First, I think they're more convenient, and the copilot can get to them just as easily. Second, since we're probably going to do an all-electric, flat-glass, modern/jet style panel, it will maintain the sleek look of the instrument display.
Switch Panel
Panel in Overhead Switch Panel
Overhead Switch Panel Backlighting
And here are pictures of both finally installed in the aircraft. The stick grip has been furnished with a DB25 style computer connector to facilitate easy installation of the wiring.
Control Stick Installed
Overhead Panel Installed
Next, we installed a map light from Aircraft Spruce. This unit is capable of red or white light, with spotlight or floodlight options, has it's own dimmer, and can be removed from it's holder to shine around the cabin.
Map Light Installed
The landing light holder was included as a "supplement" to the kit. We cut the pre-molded hole and bonded the lamp holder into the fuselage with structural adhesive while we were at the factory for the Head Start program. This lamp kit included a set of springs designed to hold the bulb in and a plexiglass lens which we will use. We've elected, howver, to go with a XeVision Xenon landing light, which provides much better lighting with a lower amp draw and longer life than a conventional bulb. This bulb comes with a controller unit that we had to mount on the fuselage wall, but the bulb is a direct replacement for the standard aviation bulb.
Landing Light (Internal)
Landing Light (External)
Landing Light Control Unit
Prior to first flight, but after priming, the lens is installed with silicone caulk.
Landing Light Lens is installed
Next we need to make a breaker box for our circuit breakers. We decided to get an engraved panel for the circuit from Frontpanel Express since Superior Panel exited the market. We also decided to mount our breakers off of the main instrument panel for a couple of reasons. First of all, if a breaker trips, there is almost certainly a real problem, and resetting the breaker will probably not help. Secondly, if you reset the breaker, and it trips again, then you should land and get it checked out, not try to troubleshoot it in flight. We like the co-pilot side placement that some other Velocity builders have used, so we elected to this as well. This is particularly nice since then these wires do not have to have disconnects in the line for removing the instrument panel (nor the canard, as most of the wiring will pass above the canard.
Making the Breaker Box
Making a Mounting Flange
Breakers Installed into Panel
Side View of Installed Breakers
Test Fitting the Breaker Panel
Breaker Panel Mounted
The first thing we did in the avionics section was to install the headset and microphone jacks in the keel for all four passengers. Since I'll be flying with Bose headsets, and will be including a four place intercom with music and DVD entertainment for the rear seat passengers, I installed stereo headset jacks (be careful if you want to do this, Spruce doesn't sell them, and you'll need to run 3-wire twisted pair for both headsets and microphone jacks).
Intercom Panels Fitted
Intercom Panels with Headset/Microphone Jacks Installed
We've purchased the PMA8000 audio panel/intercom from PS Engineering, which is a very nice stereo 6 place intercom with auto-squelch, a telephone and 2 entertainment inputs as the standard 2 comm inputs, it allows the pilot and co-pilot to operate the radios simultaneously, has a built-in marker beacon receiver, and a digital recorder for playing back ATC commands that you didn't catch all of and the like.
PS Engineering PMA8000
We've also purchased a '3 mode ELT', the new style emergency locator transponder that broadcast to overhead satellites and can track your GPS and broadcast your last known position very accurately in case of a crash or hard landing. This Artex unit is very nice, with a 5G activation switch and antennas that we can mount internally. We'll buy the NAV interface for the GPS signal later, but we needed the ELT to get our airworthiness certificate. Here also you can see our mounting location behind the 'whale tail' in the aft compartment. We've mounted it on an aluminum bracket next to the DVD player. This is the only position where it could be easily oriented properly (long axis longitudinal). Finally, the testing/arming switch is mounted on the instrument panel, and the activation warning horn is mounted behind it. The ELT antenna is installed a plate that's permanently bonded with structure to the spar box to give it the best chance of surviving a crash.
Artex G406
ELT Mounting Hole in Whale-Tail
ELT Arming Switch
ELT Warning Buzzer
ELT Antenna Installed Behind "False" Rear Bulkhead
Here you can see we've started the radio stack installation, even though we've not purchased all of the avionics yet. Here you can see we've affixed an 'L' bracket on the pilot side and a 1/4" thick piece of AL bar stock to the co-pilot side where the cant is in the panel to mount the radio trays. We bought all of the trays, even though we couldn't buy the electronics right now, so we could make a full-sized cutout and start fitting the trays in.
From Co-Pilot Side
From Pilot Side
Test Fitting the Trays
Fitting the Intercom
OK, so all of that non-sense about mounting the trays and the intercom never really worked for me. For one, I decided to go with the cheaper GTX327 transponder, which is an entirely different size than the mode-S (which is essentially obsolete with the new ADS-B system that will soon be implemented), and tapping the braces for the trays after they were attached to the panels was, shall we say, difficult to do accurately (not to mention try to get each of the boxes to line up square with just the instrument bezel sticking out). So, Jerry and I heated up the metal brace on the deep side and pulled it out, widened the hole and prepared to mount a thinner strip of aluminum on both sides (the bar I originally mounted there was easily twice what I needed). This allowed us to drill and tap the bars before installing, and mount them flush with the face of the tray, and the face of the panel (since the bars will be covered by the leather-wrapped cover later anyway, this will not pose a problem). It also allowed us to extend them down slightly to get the bigger transponder in without having to move the flash drive for the EFIS that was already mounted. I've also decided to go with the Approach Systems "Fast Stack" system, which greatly simplifies the interconnections between the radios and EFIS, etc. Here you see the grounded hardpoint I've cut to mount it to. This makes the radios almost as easy to installed as a home computer.
Mounting Radio Trays (note bar stock on both ends)
Approach Hub
Hub Mounting Base
Hub Mounting Plate / Ground Plane
Later on, once the radios were ready to go in for good, a rear bracket was required. I took a piece of thin plate aluminum and drilled and tapped in to hold the aft end of the radio trays, and then cut a short section of L bracket aluminum to flox into the "roof" over the radios. This was also pre-drilled and tapped to match the rear bracket, and trough was cleared out in the roof for the angle. Once this would dry fit, I taped over the rear bracket, screwed the rear bracket to the L, filled the trough with flox, and installed the panel to hold everything in place until cured.
Rear Radio 'L' bracket with flox
Rear Radio Bracket (with duct tape) attached to floxed 'L' Bracket
Here is a shot of the panel now, where I've mounted two jacks on it. One is for the cell phone interface to the intercom, the other for a aux entertainment input (MP3/iPod). The switch allows us to change from Aux to the Sirius satellite radio. Also, a switch at the base of the breaker panel allows us to listen to the rear entertainment source, the DVD/CD player, up front (it always feeds the rear passenger jacks).
Sirius Satellite Radio and Aux/Cellular inputs
Installing the Apollo SL30 NAV/Comm
We've now installed a used Apollo SL30 Navigation and Communications radio, a really nice unit, with a serial interface. This unit can be controlled by the EFIS/One (through our Approach wiring hub) so that when you bring up the airport in the flight planning page, it shows you the relevant frequencies, and you can select one to send to the radio directly. We've also installed a cabin speaker so we can hear, say the Automated Weather Service broadcast while sitting on the ramp loading the plane. Other nice system integration features that we just tested,
Network Hub for Autopilot and Approach Avionics Hub System Installed on Canard
Not yet complete, though the Pilot side strobe has been installed and tested, it's a Whelen PR/PG 600 system set for "comet flash". The strobe pack is installed on the center spar, and there are quick-disconnects at the wing root.
Pilot Side Wing Strobe Strobe Flash Nav and Position Lights
Strobe Pack Wing Connections
We have elected to not install any vacuum instruments, and instead go with an all-electric, computer type instrument package, probably the Blue Mountain EFIS/One system with an EFIS/Lite installed as the redundant back-up unit.
Rather than go with the factory's rather ingenious static system, whereby they embed some AL tubing in between the fuselage skins and then drill small holes in them, we decided to go with production units. We did this for a couple of reasons. Firstly, many pilots were mentioning that they had to install a "trip strip" to achieve the slightly disturbed airflow needed to get a good static reading, which is built into the raised "standard" static port. Secondly, I find it much easier to find, and examine for any debris during pre-flight, a chrome port, and I'm guessing it's much less likely to get filled with paint while in the paint booth.
So, rather than the pretty flush look, we've purchased a nice pair of static ports from Spruce, one for either side of the aircraft. This will hopefully minimize any error introduced by slipping the aircraft, say, on landing - where one port would see disturbed airflow from being "blinded" by the fuselage upstream. We've installed them aft of the door openings based on feedback from other Velocity pilots that this location is sufficiently far from the canard to get relatively undisturbed air, and still be in front of any main wing effects.
Co-Pilot Static Port
We've purchased a nice chrome heated pitot tube from Spruce. We've elected to go this route as we hope to fly the plane in instrument conditions, which might include brief periods in icing conditions. While the plane is not equipped with deicing equipment, we need to maintain the flight instruments if we encounter ice and while diverting to ice-free conditions. Also, if we carry rain in the tube to altitude, it could freeze in the tube, which would be quite unpleasant.
Per the manual, our port is lined up with the zero incidence line of the canard, 6 ¾" below the canard and 18" forward of the door line. It is then set between parallel with the fuselage and parallel with the relative wind (or dead ahead, as the plane flies forward). The pitot tube comes with an adapter that is roughed up and embedded into the fuselage with FLOX and a fiberglass radius on the inside. After cure the pitot tube in attached to the adapter with 4 screws.
Setting Up the Cutout
Glassed in the Pitot Tube Adapter Plate
Pitot Tube Installed
As part of the optional equipment that we're installing, we've already shown the LCD screens that we installed in the back of the front seats in the interior chapter, here you can see the installation of the DVD player. Here we've elected to install the DVD player in between the rear seats on top of the keel. This installation is actually on top of the sump tank in the face of the false bulkhead under the baggage self.
DVD Mounting Plate
DVD Player Mounted
In the optional section of electrical installation, we've also opted to install convenience 12V recepticles in both sides of the rear cabin, and on the co-pilot side of the fore cabin. These will be for optional accessories like a portable stereo, GPS, or game-system.
12V Power Plug
~ End of Chapter - End of Section ~