Recent Projects

RV-10 with G-900X

This project was one that everyone in the shop was pretty excited about because it was a chance to combine absolute top of the line avionics equipment with a new carbon fiber RV-10 instrument panel frame. We thought the end result was going to be great and it exceeded our expectations.

    

Watch as we build a Garmin G-900X instrument panel for one very cool RV-10.

(Click images to view full size)

This is the carbon fiber panel frame as delivered. It is designed to attach to a metal frame that mounts in the airplane where the stock panel would mount

The first task was to cut out the area of the panel frame where the metal panel inserts will mount. We put masking tape around the perimeter and cut with a Dremel cut-off wheel. While cutting, holding a vacuum cleaner hose next to the spinning cut-off wheel eliminates carbon fiber dust getting on everything (like your lungs).

Here is the frame cut out for the metal insert plates.

Next the metal mounting frame was clamped to the back side of the carbon fiber frame in preparation for drilling to attach the anchor nuts that will hold the carbon fiber frame to the metal frame.

Drilling through the two frames. After the holes are drilled, anchor nuts will be riveted onto the back of the metal frame. The holes in the carbon fiber frame will be countersunk so the metal panel insert plates will lay flat on the carbon fiber frame.

Anchor nuts riveted on the back of the metal frame. 

The next step was making the metal insert plates. The plates were laser cut from .080” 6061T6 aluminum. This plate had to be bent 4.5 degrees to allow it to conform to the bend in the carbon fiber frame. The plates are attached to the carbon fiber frame by match drilling the holes on the perimeter of the metal, and riveting anchor nuts to the back of the carbon fiber frame.

This is the carbon fiber frame with all the metal insert plates attached. It is now time to start attaching the avionics mounting trays and building wiring harnesses.

We start with this large bracket, called an LRU (Line Replaceable Unit) bracket, which is supplied with the Garmin G-900X installation kit. This bracket holds the individual LRU mounting trays. The LRUs are the remote mounted radios such as the GPS navcom, transponder, engine data processor, etc.  

Garmin provides these formed nut plates that hold the LRU racks in place

Here is an LRU bracket with several LRU racks installed. 

Not every LRU slides into a tray. On the right of this LRU bracket is a mounting plate for the air data computer which gets attached to the top of the plate.

Here are the two LRU brackets with all of the LRU trays installed. In the center is the mounting tray for the audio panel, which mounts directly to the instrument panel, it does not mount to an LRU bracket.

We always connect the two LRU brackets and the audio panel tray together with a couple of 14 gauge ground wires, just to make sure that they are well grounded to each other. 

The LRU brackets are in place behind the main panel plate in preparation for attaching them to the plate.. 

The LRU brackets mount to the back of the panel plate with these nut plates.. 

The LRU brackets and audio panel tray attached to the panel insert plate. 

View from the back with LRU brackets attached.. 

The back of the LRU brackets is a convenient place to route wiring harnesses, so we attach tie-wrap stands along the bottom of the LRU brackets. 

Here is a row of tie-wrap stands along the bottom of an LRU bracket. The wiring harnesses will be fed through the looped tie-wraps. When the harnesses are complete, the tie wraps will be tightened on the harnesses. 

Time to get started with the wiring. We’ll start with the connector kit for the LRU that is on one end of the LRU bracket and work our way across the LRU bracket from one tray to the next. 

A trick that the technicians use is to print put the pages of the installation manual that pertain to this installation, then mark the connections they need to make with a highlighter. This particular page requires that all the connections shown be made 

Stripping shielded wire is time consuming and tedious. Most technicians use a single-edge razor blade. This new tool is called a “Twisted Stripper”. It reduces the time to strip shielded wire to a second or two without the risk of cutting your fingeres to ribbons with a razor blade. Downside is it costs about $ 1,000.00, but if you do this all day it is worth it.

After the outer jacket is stripped, the braided shield is cut back so about ½” remains.. 

Next a solder terminal sleeve is placed on the wire, and shrunk with a heat gun.

Next the individual wires are stripped and a contact pin placed on the end of the wire. Note the small gap between the back of the pin and the wire’s conductor. 

The pin is crimped on with a Daniels crimper, using the proper positioner for this contact pin. The tool and positioner are specified in the Garmin installation manual. This crimper costs a few hundred dollars, but this type if work cannot be done without it. 

Next each pin is inserted into the connector. The connector is held in a Pana-Vise

The other end of the wire is temporarily labeled with its’ destination so the technician knows where to route and terminate it.

Here is the first connector with most of the wiring inserted

The connector is then placed into the body of the connector hood, and the wire shields crimped into a ring terminal that screws t the back of the hood. The strain relief is screwed to the connector hood, now the cover needs to be attached to the top. 

Here is the first complete LRU rack. Four connectors are wired and attached to the rack. The wiring from the connectors has been tied up and routed through the tie wrap on the stand. These wires will go off in a variety of directions

The next LRU is wired, this is the audio panel on the left, the LRU on the right is the GIA-63W which is the integrated WAAS GPS navcom. Think of a Garmin GNS-530W on steroids with no faceplate. 

Some of the harnesses get covered with this expanding sleeve. The reason is that these harnesses connect to components that can be removed with the connector still attached (like the display screens), so the harness can’t be tie-wrapped in place. This sleeve protects the harness from chafing.

Here is a look at some of the wiring to the engine instrument processor. The yellow wiring is thermocouple extension wire. This type of wire is required for making connection to the EGT and CHT probes.

This is the autopilot connector. The autopilot controller mounts in the hole seen above the LRU bracket.

With all of the LRUs wired, the wiring has been routed to the end of the LRU brakets. The red power wires and black ground wires have been separated so they can be routed to the circuit breakers and the ground bus.

The black ground wires are routed together in preparation of attaching to the ground bus which is the side of the LRU bracket.

The ground wires are tied in groups and cut to length.

With terminals crimped and attached to the LRU bracket the ground bus is complete. This single-point grounding, all electrical components ground to this one area. Later, a larger main ground wire will be attached here for connection to airframe ground.

We use pre-punched copper bar to buss the circuit breakers together

The wiring for the circuit breakers is routed to the circuit breakers.

A piece of expanding sleeve was placed over the harness for protection.

The wires are grouped according to which breaker they will connect to , tied, then cut to length.

TThe wire ends are stripped and ring terminals crimped on, then attached to the circuit breakers

This is a harness that is going from the panel out to the aircraft to connect to devices mounted in the tail, wings, etc. These harnesses are first covered with expanding sleeve. These harnesses will terminate into AMP CPC connectors, which will plug into aircraft wiring harnesses we will fabricate.

These are the wires with pins crimped on before insertion into the CPC connector. Note the masking tape on the wires that identify their function.

Here is an overall view of the back of the panel with two of the off-panel harnesses complete with connectors. The connector on the left is the firewall forward connector which is made of metal which we prefer when penetrating into the engine area.

The antenna cables connect directly to the back of the LRU racks as send here. We use RG-400 coaxial cable and crimp-on RF connectors for all antenna connections

The G-900X system requires a dual VOR / dual glideslope signal splitter in order to use one VOR antenna to feed the system. We mounted the splitter to the side of one of the LRU brackets.

This is the back of the completed panel. The white and blue tubing are the pitot and static tubes, connecting to the air data computer, autopilot, and Aspen backup flight display. The aircraft pitot and static sources will attach to two tubes leading from the panel.

First power-up. Everything came on as expected, now we will do the G-900X pre-installation setups and calibrations before delivery to the customer.

This panel was painted with DuPont products. We filled the pinholes in the carbon fiber frame, then primed it with a high-build primer, and then painted it with Chromabase paint, and Chromaclear clear coat with flexible matting added to bring the shine down. The metal plates were prepped, and primed with DuPont Variprime self-etching primer, then painted with Chromabase paint and Chromaclear clear coat. All paints were shot through an HVLP paint gun.

A few of the panel details such as wiring the electrical rocker switches were not covered in this article. That part of the job created enough material for another article and that will be coming shortly.

This was a great opportunity for us to build another state of the art instrument panel, and we had fun doing it (plus the customer loves it).

 

Stay tuned for more.!