Avionics Fans

This plane will end up with a lot of equipment both on the panel and sitting behind the panel.  This leads to heat generation which isn't the best thing for electronic components.  The RV-14 kit actually has you install two fans on the glare shield and many builders of the RV-10 have taken it upon themselves to add a few fans of their own.  I decided to join in on the fun, and at the same time log a little build time.

The idea is fairly simple, mount two fans under the glare shield to push the hot air out and replace with cooler air under the foot well. An added effect to these is they will also function as defrosters on the windshield.  At first the idea of flying at any time when I have ice on my windshield seems a bit nutty but my neighbor who is a military pilot said it has more to do with condensation. As a result some people have wired these fans to a switch labeled 'defrost' and manually turn it on and off.  I'm not going to do that but rather have them wired in a way that they remain on anytime I have the master on.  The added benefit is when you shut down the plane you'll know your master is left on if you hear the fans.

In regards to fan selection most any computer style cooling fan will probably work.  The common size seems to be 80mm or around 3" fans although I've seen larger ones and smaller ones used by builders.  I went with 80mm and probably spent way too much time selecting the ones I wanted.  In my typical overthinking method I wanted ones that were relatively thin as to not impose onto the forth coming avionics install, while still moving a lot of air and keeping someone quite (Which is silly given the engine is 2 feet away). I selected the OD8025-12HB from Digi-Key with an associated cover (10020-1-5170). These fans seemed to offer a good balance of air throughput and sound.

Something to note on the installation is there is very very little margin of error in lining up the fan hole with the guard attachment holes. On some of the side about a 1/16 of an inch hang out under the grill screen.  I'm not particularly concerned with that because I will be covering the glareshield with some type of material which will require me to work it around the holes so it will end up getting recovered.  However if you don't plan on doing something like that and that detail will bug you then maybe do the hole a bit smaller than the fan size.

Holes Drilled

Installed Top

Installed Bottom

New Year, N Number and Panel/Electrical Designs

N Number

Last year I reserved N405JW but I wasn't really sold on it.  Over the last year I've been waiting for something that I liked better.  A fantastic resource to use is an aggregation site at http://www.tailnum.com/. This makes the registry searchable as well allows you to see newly released numbers available.  Hey and it also happens to be maintained by a fellow RV builder. While it's very possible I might change it again, at this point I registered an am going with N910W. Easy to remember and fairly self explanatory being a combination of the build and my last name.

Panel Design

Haven't made a lot of physical progress in the build over the last month.  I'm awaiting the finishing kit and decided to use the time to jump into finishing up a few planning items. Not only did this require putting some things down on paper but an extensive amount of reading! In the end I think I ending up reading 5 books and countless posts, logs and other bits of information. The last book I read on the subject really should of been my first book and is Marc Ausman's Aircraft Wiring Guide.  Marc was the original designer of the Vertical Power system that I'll be using.  The book is short (80 pages), concise and is a great intro into the subject.  It has a bit of marketing material on the VPX but since I'm already sold on it I wasn't bothered.

Digging into panel design is so far my favorite part of the build.  I actually started looking into this before I even ordered the first kit.  The ability to customize essentially everything that goes into it is a huge draw and really shifted me from the certified market over to the experimental.  The path of progression started by looking at other panels, learning about the various components and trying to determine a starting point of what fits your flying mission.

I started drawing out designs on a piece of paper and soon moved to using MS Paint in sort of a Frankenstein panel creation method.  This got me through a good 10 or so revisions.  Recently I transferred that over to a Visio drawing which is a lot easier to modify and maintain.  Pending any major changes in product lines this is very close to what I will go with.

Panel Design

The quick rundown is I wanted a solid single pilot IFR capable platform.  I want to have full access to everything with a good bit of visibility for night flights where I don't have to wear a headlamp or install a ton of lights.  I'm obviously a Garmin fan because essentially the entire panel is made up of their product line.  What you can't see on the panel are the remote comm #2, transponder and ADSB stuff which will be remotely controlled through the other devices.

Each rocker switch will be customized illuminated switches and everything flows in a particular phase of flight process.  Ie Left side are the starting functions, first set of buttons are the most used ones, the lights are together and the A/C Climate stuff is together.  I may move the ELT things (Top left) around but not sure.

I'm putting a lot of functionality on the control sticks themselves. I will essentially be able to fly 'hands on' during the critical phases of flight (Take off & Landing).  Not shown is the throttle, props and mixture which will be on the center console.

Electrical System

Think about building a car, then think about trying to figure out how all the wiring is connected between everything and you'll have a good idea of what goes into building a plane. You can buy a harness and use some plans from Vans but you'll end up with a very plane Jane set up.

Not interested in that approach I've spent the last few months off and on either reading about electrical systems or working on a set of drawings to the design.  I'm off the hook on somethings like the interconnecting harnesses between the avionics.  I'm going to get those through Stein Air on a majority of the devices which saves time, but really saves headache and heartache of trying to complete that on my first project.

What I first focused on was the component layout of the plane to determine where physically everything will be located.  This also forces you to think about everything and even in this basic exercise I added and removed things multiple times.  The endish result looks like this-

Component Overview

Once you have a panel design figured out and where you want to put the components you start to dig into how power is going to be distributed.  This has quite a steep learning curve as it requires you to read about the requirements of your planned components, look at other peoples designs and make some decisions.  

What a mess right?  I promise it makes sense... or at least I hope it does.  It really gives you a great idea of the various wires and connections you'll need to make to get power throughout the plane. It again forces you to really understand what you're putting in the plane even down to the wire size.  I probably made at least 10 major revisions on the above and as it stands now will probably be tweaked continually throughout the life of the plane.

I found out that electrical systems are HIGHLY debatable.  There's no one right way to do it and what is within the comfort level of some people is not for others.  The basis of my design is to allow several backup options if I lose ship power in IMC (Clouds).  If I can see out the plane window I'm less concerned about being able to fly and land safely but in the clouds losing something like attitude indication can be a real problem.

What I'm going with is a single main battery with dual alternators. I'll also utilize a smaller backup battery for the main EFIS, GPS and a few other items.  The last resort is the Garmin G5 which also has it's own backup battery.  Again my goal if I have a problem isn't to continue the flight through IMC until I run out of gas, it's to get out of the clouds and land.  If your mission is otherwise then you can really build it as redundant as you want.

These are just a few of the drawings I wanted to share.  I would suggest in building your project you put together a 'book' of drawings in whatever format you want.  So far I have a total of 7 separate drawings that cover in details some of the specific items in the plane.  Will be invaluable in future troubleshooting or modification en-devours.