13.4.3 Pitot Tube Installation

This entry is part 1 of 5 in the series 13 - Electrical / Instruments

The pitot tube is what measures the airflow so that we know how fast the airplane is moving through the air. This sucker was pricey too. Malcolm had some steel stock with the same cross-section as the pitot tube. So I cut a length of it and drilled four mounting holes in it.

The manual calls out the location of the pitot tube as 6.75 inches below the canard and 18 inches forward of the door.

+ marks the spot.

Closer

And the hole is cut out.

The sleeve and pitot tube dry fitted.

Then the structural adhesive is mixed and the sleeve is permanently installed. The alignment is important to insure a correct airspeed indication.

Forward alignment is accomplished using a framing square clamped to the canard bulkhead and visually referencing the pitot tube to the framing square.

And we used a digital level to verify that it’s… level. The tripod is used to hold the position while the epoxy sets.

13.4.2 Static Port

This entry is part 2 of 5 in the series 13 - Electrical / Instruments

While I was waiting for the bolts to arrive, I installed the static ports. The manual calls out 9″ below the canard and 9″ aft of the canard bulkhead. They used to be mounted lower and farther aft but I like the higher/forward position.

Once the location is identified, a .5″ hole is drilled.

The foam is opened up, masking tape is used to cover the static ports, structural adhesive is applied and it’s installed.

13.2.1 Instrument Panel Mounting

This entry is part 3 of 5 in the series 13 - Electrical / Instruments

I mounted the instrument panel a while back. That task involved creating mounting tabs on each side of the fuselage and a mounting tab on the center keel. Then nutplates were riveted to the tabs. It worked fine but the problem is that it will be almost impossible to remove the panel once the engine controls (Throttle, prop and mixture) are installed. There are a couple of approaches to work around this issue. Malcolm’s is to create a sub panel that the engine controls are mounted to and that sub-panel is permanently attached to the fuselage.

First, the location of the engine controls is determined. There’s a bit of guesswork involved since I don’t know what the correct spacing between the controls should be until they’re drilled. So I checked with a couple other builders and came up with 2 – 2.25″ between each control. I went with 2.25″.

This picture shows the left side of the instrument panel with the location of the Throttle, Prop and Mixture controls. I’ve also created the line where EC (Engine Control) sub-panel will be cut away from the main panel.

Partial cuts are made in two places along the two lines. Then structural adhesive is applied to the back of the sub-panel and the whole panel is screwed and clamped into position.

Once the adhesive has cured, the cuts are completed and the main panel is removed leaving the sub panel attached to the inner skin of the fuselage.

Then tape is applied to the front and back of the main panel and a release agent is applied.

The main panel is reinstalled and reinforcing layups are applied to the back of the sub-panel and extended over the back of the main panel. This will create a flange that will be used to connect the main panel and the sub-panel.

View from the back of the panel.

Then holes are drilled through the main panel and flange on the sub-panel and nutplates are installed. After that, the holes for the engine controls are drilled into the EC sub-panel.

Next the EC sub-panel will be painted and the engine controls will be mounted.

 

13.3.2 Ground Power Plug

This entry is part 4 of 5 in the series 13 - Electrical / Instruments

My good friend Albert, gave me a ground power plug. These are helpful if you ever have a dead battery and need a jump or you want to run the avionics on the ground for testing.

But where to put it? After trying a couple locations, under the battery shelf looks like the best location. So a mounting bracket is needed. I brought the plug home with me after the last trip down so I would have something to do.

I got a foot of 2″x1/8″ aluminum angle and cut it in half. Then I clamped the two pieces together and cut an opening for the plug. Then I drilled the four holes for the mounting  bolts.

Next I pulled the two pieces apart and mixed up some Resin Research epoxy and bonded the two pieces back together.

Finally, I drilled six holes along the top and tapped them. This is how the bracket will be mounted to the underside of the battery tray.

13 Ground Power Receptacle

This entry is part 5 of 5 in the series 13 - Electrical / Instruments

When the battery in a car is unable to start the engine, you can connect a set of jumper cables to get the engine started.  Many FBO’s aren’t real keen on “jumper cables”. Too much potential for connecting them wrong and doing major damage to the aircraft electrical system. Most 28 volt aircraft have ground power connectors. It allows you to connect the single cable to the aircraft with no chance of connecting things wrong.

Albert gave me a Ground Power Receptacle a while back so now all I have to do is figure out where to put it. I was going to put it under the battery tray but once I looked at the size of the plug I realized that wasn’t going to work.

So I put it in the nose. This way, it’s easy to get to on the ground when the nose gear doors are open. People that use the factory nose landing light can’t do this because the landing light is in the way. Yet another advantage of landing lights in the canard.