Teflon coated spaghetti

Down getting in Jim's way again, this time to learn how to make a wiring harness. Things are going pretty well, and it looks like we'll have the dash and harness back home in mid-June.

 Each wire has been written down,

entered into a spreadsheet as it's cut,

and heat shrink labels are printed and slid on before being put into place.

This was half full at the beginning of the day.

 

Only a few more wires to cut, then we start wrapping the bundles tomorrow morning.

Recreational Mobility

I'm being mentored (and my wiring harness is being built by) Jim Ratte of Recreational Mobility. Legendary pilot/author Richard Bach adopted his SeaRey "Puff" from Jim, and speaks very highly of Jim in "Travels with Puff".


Jim is now on Facebook, if you have any SeaRey questions I can't recommend him highly enough.

Fun in the sun

Courtesy of Dan Nickens, Giuliana got her first SeaRey flight at the Garner's Landing fly-in

And she won a prize in the drawing, a PFD donated by the SPA. 

Then we went to work at Sun n Fun in Air Ops. I was able to share a few words with The Man

Sparky got her yellow "rookie" Air Ops hat

and was recruited by Greg Koonz to help in the ribbon cutting part of his act. 

In the meantime, Jim was hard at work, and kindly sent some pictures of the hardware mounted on the support trays. A center support will be added later.

Rack it up

The panel made it safely to Jim's and it's now in the wiring jig, where it will remain for the next few months.

With (a lot of) help from my friends...

One coat of natural stain, 3 coats of spar varnish later...

Now it's off to Jim's to take the air out of those holes.

Ospreys (done by frickin' laser beams)

While picking up the labels at Bay Engraving, another idea struck me. Talking it over with Kurt, we decide to try and burn an image of an Osprey into the panel.


The first problem was that because of the wing getting in the way of the suspension arm and the size of the panel, the laser could only reach so far. This limited the placement of the image to the right center, which was ok because it took away any temptation ot make it big and obscure the beautiful grain on the right hand side.

Using one of the old pulls, we experimented with the technique and limitations, and like so many who have become involved building Osp, Kurt is a perfectionist took his time making sure it would come out right.

I picked a couple images, converted them to outline and played with the placement...

Kurt burned a few test images to see which one would come out the best, and played with the resolution/shadowing of the images...

while I obsessed with exactly where it should go and at what angle. 

It was a multi-stop process to make it happen. Kurt appreciated all the hard work we've put in, and while there was an element of risk doing this, he wasn't going to be the one to mess it up.

Finally, the panel was put into place. A scrap piece of veneer was placed over the real panel and burned to verify that everything would work. (Note the QB logo from another job.)

Then he placed and burned a piece of plexiglass over the final location for one last check.

After that there was nothing to do but take a deep breath, start it up and try not to bump the machine while hovering over it.

It came out beautiful, and as usual I was so excited I did not get a better picture. 

A quick run to the airport confirmed how good it looked.

Back to Gordon, first to fix a small section of veneer that had splintered during all the handling. Can you spot the repair?

Thought you might like to see some of Gordon's non-airplane work.

The next to last step, a light coat of natural stain

Before

After. I love how the stain made the grain just pop. The pic does not do it justice. 

A couple days for the stain to outgas, 3 coats of spar varnish, and it should be at Jim's before Sun n Fun.

False starts, fine tuning, and redos

With the labels attached, for some reason I decided I wanted a glovebox in the dash. I spent some time with an old pull trying to make one up, but it just wasn't going to happen.

When fitting the panel we found the light bezels did not go all the way through the dash, some gray of the foam showed, so I carefully used a sharpie to darken the inside of the steam gauge instrument rings. I didn't want to hit the veneer because the capillary action of the wood grain would draw the ink out, ruining the area.

I also realized that I had forgotten the label for the gear circuit breaker, so that gave me a chance to try out the doublestick tape method of attaching one.

"Homebuilt" aircraft require a warning to passengers that the aircraft they're about to fly in was not professionally built. This warning is usually in the shape of a big, ugly generic placard, and while the phraseology is specified, unlike N-numbers the font and size are not specified in the FARs. I decided OspRey's should have some elegance and style.

More power!!!!

When I started planing my build I intended to use the external Rotax alternator, since the internal PMG only produces up to 18 amps. (Hello, electrically heated seats!!) However, as I got to know the SeaRey I realized that it had a weight problem, and decided to reduce the “goodies” to try to keep the electrical load within the 18 amp limits of the PMG. Good practice says you should limit your electrical load to 80% of the generator output, and the 914 manual recommends that if your aircraft requires loads above 12-15 amps you should use the external alternator. (Goodbye, electrically heated seats...)

While cutting the panel Jim showed me the external alternator he was installing on another aircraft. It was smaller than I thought, and only 8#. Of course, in addition to those 8# there is the wiring, etc it adds to the airplane.

As we continued cutting the panel we talked more about the pros and cons of adding the external alternator vs the weight penalty. The generator on the Rotax 914 is a “permanent magnet generator”, which means the magnets are fixed to the outside of the engine, the engine flywheel acts as the armature, and the rotation of the engine directly produces the electrical current for the plane.

Since both fuel pumps are electrically powered, as the manual states “In all cases the electrical system design should assure that no single failure mode (IE: alternator, battery, voltage regulator) causes both fuel pumps to stop. Careful design consideration must be given towards this issue!”

While it would take a lot to cause a PMG to fail, Jim led me down the primrose path by asking me what I intended to do when I started flying Osp. “A lot of landings!!” I replied. We then discussed the power output of a generator, that it only developed power when at a higher rpm, and the lower the rpm, the lower the electrical output. As we all know, when in the pattern full power is used for takeoff but once at altitude power is reduced for level flight on the downwind, and further reduced for descent and landing, resulting in lower generator electrical output, and fewer amps for the system.

So while in the pattern, what's going on? Radio calls are being made and received, nav/strobe/landing lights are on, power is being used by the Skyview, but most importantly-the electric landing gear is being cycled, putting a high load on the electrical system.


The SeaRey is the only retractable gear aircraft I have ever flown that does not have a backup gear extension system, and it's kept me up many times at night. It's an elegant, yet simple system using dual electric motors for main gear extension/retraction and a garage door spring for tailwheel retraction (slaved to the left gear actuator for extension). But since it uses separate gear actuators, a bad day could see you with the gear stuck up or down, and a real bad day (like a failed connection ) could leave you with one gear up and the other one down, and few good alternatives.

More realistically, when doing pattern work the combination of low electrical power output and high electrical demand might end up inadvertently draining the battery, leaving you without enough power to extend the gear. While you could go fly around and charge up the battery, the SR has a narrow weather window, and if the winds or weather were kicking up, that might not be a good option.

End result, I'm reversing my decision not to go with the external 40 amp (Hello, electrically heated seats!!) alternator, and will be adding it to Osp.

Travels with Puff

In case you haven't heard, Richard's book about his adventure with Puff is now available from Amazon, or even better, from your local independent bookstore.