Jan 07, 2020     Researched GTN 650 installations in RV-8s - (0.6 hour) Category: Research

Researched how difficult it is to install a GTN 650 in an RV-8, since there is only about 3/4" of space behind the radio. Found several people who have done it without cutting a hole in their bulkhead. So I think I'll be good to go. Still going to research 90-degree backshells...

  Jun 15, 2010     Electrical system improvements and organization - (5.3 hours) Category: Research

I spent much of the day researching some critical, final questions that could affect the design and/or installation of my electrical system and avionics. Questions such as:

1. Can I mount the GRT Manifold Pressure sender on the front side of the firewall? (No, it's designed to be in the cooler environment aft of the firewall.)

2. Would a plastic Bussman fuseblock be OK forward of the firewall? (Yes, it should be OK, but using inline fuses for the "always hot" electrical items might be a better way to go.)

3. Does the GRT AHRS require a separate circuit breaker, or is it powered in series with the display units? (It needs its own C/B.)

4. How critical is the 6" requirement for the lead between my battery solenoid and the battery bus? (It's critical if you want to call it a true "bus." Otherwise it's a "distribution point" or something else.)

5. Does the Dynon D-10A require an external USB port?

6. Does the audio panel default to Com 1 if it loses power? If so, having Com 2 on the Battery bus so I can use it as a pre-start "Clearance Delivery radio" no longer makes sense.

  Apr 20, 2008     Instrument panel design update       Category: Research

(2.5 hours) I noticed that ePanelBuilder.com has added some of the newest generation of avionics, plus some different switches and cockpit components to their program, so I re-drew my instrument panel to reflect the proper items.

The changes include the new, taller GRT EFIS displays and the replacement of the previous audio panel with the PMA9000EX. I also added the CO Guardian unit and the ELT remote indicator to the panel, turned the autopilot source selector switch 90 degrees, and re-positioned the transponder, dimmer switches, and USB jacks.

[Design entirely superseded.]

  Jan 01, 2008     Panel and avionics design Category: Research

(15.5 hours) This entry covers the last few days of research and electrical work. I have mostly finalized the panel design; purchased switches, knobs, and lamps; defined switch labeling and functions; designed sub-circuits (such as the reed switch-controlled one that will monitor the pitot heat circuit and turn off the annunciator light if the heater fails.) Due to the taller EFIS displays I'll be installing, I will not be able to use the scratchbuilt annunciator panel I built previously. Instead, I'll use a cluster of nine 12x16mm rectangular LED lamps with integral legends. They should look very nice.

I also ordered the ProHub data bus from Approach Systems, Inc. to connect my avionics. This will save a ton of time when I wire the panel, plus it will allow for future upgrades and panel modifications. [Eventually superseded.]

  Dec 20, 2007     Electrical system design       Category: Research

(22.5 hrs.) This entry represents the past two weeks of work on designing the electrical system and the instrument panel. I've spent a lot of time thinking through each electrical component, how it will be powered and from which bus, various failure modes, and panel ergonomics. I distilled my systems designs into a series of detailed schematics, drawn with a CAD program called SmartDraw 7 (which I highly recommend!), and I used ePanelBuilder.com to tweak the main panel design. EpanelBuilder does not yet include the new high-resolution GRT screens (which are taller than the old ones), nor does it allow me to draw rectangular annunciator lights, or toggle switches that move left/right instead of up/down. Otherwise the panel is pretty close to accurate. [Panel superseded numerous times.]

My Main Switch Panel, on the right side of the cockpit, came out pretty nice. I have to consider whether it's a good idea having a fresh air vent directly above it. I don't want moisture blowing out of the vent onto the switches. I might have to move the vent someplace else -- maybe up one hole, where the compass is shown.

  Dec 06, 2007     Electrical system planning       Category: Research

(7.5 hours) I worked most of the day on electrical system concepts and diagrams. After a long series of emails and forum postings with various people including Bob Nuckolls, who recently pulled the Z-13/20 diagram from his AeroElectric Connection (AEC) book because it "sucks" (his word!), I have decided to go with his Z-12 diagram, modified for my own priorities and goals. The Z-12 is a dual-alternator, single battery system, with an aux alternator.

My alterations to the Z-12 system are as follows:

1. I will have a solenoid-activated alternate E-bus feed path from the battery bus to the E-bus.
2. My E-bus is an "Essential Bus," not an Endurance Bus. If I lose my main alternator, my E-bus will allow me to comfortably and safely divert, under IFR, to the nearest suitable airport where repairs can be made, without using the main battery. (I do NOT want to necessarily continue my flight to my original intended destination, as the AEC book proposes. I disagree with that concept, as I think it's not great airmanship to overfly a suitable airport with a known malfunction in an airplane.) The Essential bus will feed my two main EFIS displays, AHRS, EIS, Garmin 430 Com/GPS, autopilot, and transponder. Once in the vicinity of the divert airport, I can turn the battery back on and lower the flaps, use the landing light if needed, etc. My backup EFIS has an internal battery.
3. I will have a backup starter button powered from the E-bus. This will allow me to start the engine in the event of a switch failure in the stick, and also allow me to re-start the engine in a time-critical inflight situation, without having to throw the guarded "Start Arm" switch first. (As a side feature, it will also allow me to start the engine in the event of a battery contactor failure, simply by closing the "E-bus Alternate Feed" switch. I don't anticipate using this feature because as I alluded to before, I do not fly airplanes with known significant malfunctions. It might be used to taxi the airplane to the shop, however.)

  Aug 10, 2007     Electrical planning Category: Research

(2.5 hours) I re-thought a few issues with the electrical system, the main one being the location and function of the engine start switch(es). Previously, I had planned to have a pushbutton starter on the instrument panel. After discussing this with several people, each of whom pointed out that it's a good idea to keep the stick back in your lap while you're starting the engine of an RV-8, I've decided to put a start button on the stick, and a guarded "Starter Arm" switch on the panel. That way, I'll be able to keep one hand on the stick and the other on the throttle for start. After the engine is running, the Starter Arm switch will be turned off, disabling the button.

This got me thinking about an emergency inflight start, a situation where it would be easy to forget to re-activate the "Starter Arm" switch while fumbling for the fuel selector, ignition switches, mixture control, fuel pump switch, and flying the airplane. Therefore, I think I'll put a good old fashioned starter pushbutton on the panel, wired in parallel to the one on the stick. The panel-mounted one will be "hot" and available whenever the master switch is on.

  Apr 10, 2007     Fuselage plans Category: Research

(1.0 hours) Studied fuselage plans and checked off most of the stuff that is either already accomplished on the QB kit, or applies only to the RV-8A. Noted that there does not appear to be any of the recommended Proseal at the bottom of the firewall, as mentioned in the assembly manual.

  Feb 02, 2007     Annunicator panel Category: Research

(1.6 hours) Today I bought most of the remaining supplies I'll need to build my annunciator panel. I also finalized the printed legends I plan to include. They are: Low Voltage, Low Oil Press, E-Bus Feed, Starter On, Fuel Pump, Pitot Heat, Landing Light, and Smoke Armed.

I ordered some high-intensity 5-mm white LEDs (Part # LED5-40DG-WH) and reflectors from TheLEDLight.com. Photos coming soon.

  Feb 01, 2007     Annunciator panel Category: Research

(1.1 hours) It's been bitter cold in my workshop, even with supplemetal heating. My propane heater warms the place up OK, but I can only leave it on for about an hour before the fumes start building to unhealthy levels. I recently bought a wall-mounted, fumeless propane heater and a 100-pound propane tank, both of which I plan to install as soon as I can get permission to cut a hole in the wall of the hangar for the gas line.

Today, I spent some time in the aviation department at Lowe's, doing some "store-aisle engineering" on my planned annunciator panel. I purchased two different sizes of aluminum U-channel. This is the stuff used to protect the edges of plywood. There were two sizes that just happened to "nest" perfectly. I also purchased a small sheet of Lexan for the lenses. Next up will be some white LEDs and some colored light-filter material like the stuff used by the photographic and video industry. I'll post some photos of the project as it progresses. (Gotta keep working on something, even if I can't work in the hangar temporarily.)

By the way, credit for this annunciator design idea must go to Paul Dye, a Houston-based RV-8 builder (and NASA Flight Controller) who haunts the Van's Air Force web forum and dispenses great ideas like they were candy... Thank, Paul!

  Jan 18, 2007     Panel Planning - (5.5 hours)       Category: Research

I spent a considerable amount of time today coming up with my latest plan for my instrument panel.

I have been increasingly unsatisfied with the interfaces between the AFS-3400, Garmin 430, Garmin SL-30, and the TruTrak autopilot. It seems to me that, while the AFS folks claim their EFIS display will "work with" the other units, there is little "designed compatability" between them at this point. Conversely, the Grand Rapids Technologies (GRT) website contains a ton of specific, direct, operating instructions for the exact GPS/NAV/COM and autopilot units I want to use. For instance, their manual describes, in great detail, how to fly a coupled ILS with a Garmin 430 and a TruTrak DigiFlight II VSVG autopilot, along with all the indications and annunciations you'd actually see.

Because of this, I sat down and played a few "what-if" games with the ePanelBuilder software, just for fun, and came up with the panel below, which still retains the redundancy of my previous design, plus some extra goodies. The Turn Coordinator may not be needed -- I'll have to do some more research.

I also downloaded and printed out both the AFS-3400 and GRT Horizon EFIS manuals. I'll be studying them carefully during the next few days, while I'm on a trip. This panel would cost me about $9k more than my previous design, when I add the second display, XM weather receiver, and Garmin 330 transponder. (I've got to have those if the EFIS is capable of displaying their data!)

  Sep 05, 2006     Parts sourcing Category: Research

(1.0 hours) Researched parts and systems.

  Aug 30, 2006     Panel planning and systems study Category: Research

(3.0 hours) Panel planning and systems study

  Aug 29, 2006     Parts sourcing Category: Research

(2.9 hours) Parts sourcing

  Aug 28, 2006     Shop construction       Category: Research

(25.0 hours) This entry covers my contributions to the shop re-construction, painting, trim work, etc., over the course of two weeks. Much of the work was performed by Jim Franceen and his crew, who actually cut and hung the plywood. I painted the walls, installed the floor moldings and flourecent lights, and all the other little details.

  Aug 27, 2006     Parts sourcing Category: Research

(3.7 hours) Parts sourcing.

  Aug 25, 2006     Electrical and systems planning Category: Research

(5.3 hours) Electrical and systems planning.

  Aug 24, 2006     Systems planning and parts sourcing Category: Research

(3.0 hours) Systems planning and parts sourcing.

  Aug 22, 2006     Systems planning and parts sourcing Category: Research

(1.5 hours) Systems planning and parts sourcing.

  Aug 20, 2006     Parts and systems planning Category: Research

(3.3 hours) Parts and systems planning.

  Aug 19, 2006     Electrical and systems planning Category: Research

(4.0 hours) Electrical and systems planning

  Aug 17, 2006     Electrical system planning Category: Research

(2.5 hours) Electrical system planning

  Aug 16, 2006     Electrical system planning Category: Research

(3.0 hours) Electrical system planning

  Aug 26, 2005     Parts sourcing Category: Research

(2.5 hours) Parts sourcing.

  May 14, 2003     MAC elevator servo Category: Research

(2.5 hours) Researched and purchased 5-pin connectors and rubber grommets for MAC servo cable installation.