The following is a summary of the second annual condition inspection.
Started the annual condition inspection by uncowling her (the plane, not my wife just yet) and draining the oil. While the oil drained I started removing fairings and covers.
Opened up the underside of the wings.
Got the spinner off.
Removed the empennage fairing and inspection covers.
It has been two years -- or I should say 24 calendar months -- since I had the original pitot/static/transponder check done. It's coming due the end of this month. Now is the time to get it done, when the plane is open for the annual. I had Brian Gerdes of Gerdes Aviation come to the hangar to do the inspection. He did the first inspection and I was thrilled with his knowledge and the quality of his work. Here's that pneumatic suction mount dealie that holds the static air source up to the static port (the other side is masked off).
Here's Brian's airspeed/altitude test unit. He mentioned that he's getting a brand new setup that's all digital and self regulating, and just has a simple remote control where he can just dial in whatever he wants and the machine does all the magic. This setup is a little dated, but it works.
Here's the transponder test setup about a foot away from my antenna on the belly.
Brian went through the altimeter tests, and just like the previous set of results, the Dynon was pretty much on the money throughout the range. My "steam gauge" altimeter has been reading a little low, and this test confirmed that. I plan on replacing both my airspeed and altimeter gauges with higher quality (i.e. United) gauges at some point when budget permits. They are still well within range...I mean being off 35 feet when 100 feet is allowed...that ain't so bad. But of course I want perfection. I'm just not willing to dump a grand into it right now when what I have is unquestionably functional. Van's airspeed gauge is pretty much a piece of junk. The nice thing about it is that it comes pre-marked for my airframe. The down side is that it's not very accurate...well, it's off by about 3-5 mph throughout the range. That's not a huge error, but like I said, I want perfection. When I have a few hundy burning a hole in my pocket I'll replace it.
Brian finished up the inspection and headed down the hangar row to do another one for another RV pilot. Time for the first "major" project. Over time, my throttle and prop control cables have gotten pretty badly "gummed up." I don't know how to describe it other than this...the throttle was a bit stiff through the range, and when pushed into the wide-open position, it was really stiff trying to pull it back. The prop cable was just plain stiff all around. Very hard to move. Usable, and in a way it had its own built-in "friction," but it was not right. At last year's annual I did my best to lubricate it, but it did almost no good. I've been flying around for hundreds of hours with the quality of the cables degrading steadily. It's time to fix it!
While I was at it, I wanted to replace my throttle quadrant. The way I had mounted it, it wasn't exactly the most rigid setup. It was attached on both sides to the panel, and the left side was allowed to flex a bit. This wasn't an issue until the cables started getting gummed up. The way I originally mounted the quadrant was, well, not optimal. Also, I installed the quadrant before I had my actual seat cushions, so I had taken a "best guess" as to where to mount it so it wouldn't be in the way. It was just fine in that respect except for when I had my feet "low" on the rudder pedals (off the brakes). In that position my left knee just barely contacted the friction knob. But just barely is way too much!
So I yanked the old quadrant out in order to start work on the new setup. I didn't really have a plan yet. This was the "R&D" phase. Removing the old quadrant was a pain in the ass, because its sides are closed in, and access to the cotter pins attaching the clevis pins was not as easy as it could have been. Anyway, here's what I'm working with. This is the original hole in the panel that has served me well.
Another shot of the same. You can see the one screw attachment in the upper left. Just one attachment point on the left side allowed the old quadrant to flex once those cables started going bad.
This is the old quadrant. Kinda dumpy looking now that I have something nicer to compare it to... You can see the sides are totally closed off other than some small holes through which you have to insert the clevis pins.
One other crummy thing about this quadrant is that the holes in the control arms are all co-located. That is, they're all at the same height. This is good for throw geometry but is not really necessary, and it makes for potential interference. Van's actually has a service bulletin or letter about this.
Enter the replacement...this is not your father's throttle quadrant! This is the SMCT3L (side-mount curved-top 3-lever) quadrant from DJM Manufacturing. DJM is Dayton Murdock, a machinist who happens to be an RV builder himself. What better way to go than supporting an RV builder who makes a fantastic product?! This puppy is superior in every way, to boot. The first thing that grabs you is the set of beautiful anodized aluminum machined knobs. They are nothing short of works of art.
The frame is made using black anodized aluminum, with thinner and wide-open sides. The levers are drilled staggered. The clevises don't come anywhere near the top.
The friction mechanism is more sophisticated and works better. It's smooth all the way through the range at all friction settings.
On the old quadrant, the friction bolt is just sliced off on the outside of a nutplate. On this new quadrant, there's a special retaining nutplate that holds the friction bolt in place. Much cleaner design.
The engraved and white painted labels are aesthetically appealing and obviously functional. (My previous quadrant had no labels whatsoever other than the painted knobs.)
So today's project wasn't to get the new quadrant in. At least not quite yet. I wanted to get to the bottom of what was going on with my cables. So the first ordeal was getting the old cables out of the airplane. The mixture cable was still smooth and free moving it by hand, so that was staying. The prop and throttle cables -- I could barely move the throttle cable by hand, and the prop cable, without the leverage of the quadrant, was for all intents and purposes completely frozen. So I ended up cutting the cable on a band saw. First I wanted to see exactly how it was constructed. Hard to see here, but you've got the inner cable, a thin sheath around that, a plastic inner housing sheath, the wound cable outer sheath, and then the protective plastic on the very outside.
I made a few cuts and managed to free up the ends. Check out what I found! The inner cable's plastic had broken and was all jacked up, peeling off and piling up in there.
Another shot of the same.
In this photo, on the top you can see a perfectly good cable, then my throttle cable, and then the prop cable. I tried to figure out what would cause this. You might immediately jump to "melting" or a heat-related issue. It wasn't heat, because it was the cockpit end of one of the cables that had the problem. It wasn't a bend radius issue, because the throttle cable has no aggressive bends in it at all. I wouldn't really say it's "wear and tear" either, because the prop cable doesn't exactly see all that much movement. The throttle cable, sure, especially with all the formation flying I do...but I don't believe it was normal wear and tear that caused this.
So here's my only theory. Remember how the old quadrant's sides are closed off? Well I have a vague recollection of something I did when I installed it, when originally getting the cable throws set up properly. I'm not positive, but I believe I did this -- I believe at least one time I put the clevis ends on the quadrant when the quadrant was on the bench, installed the quadrant in the plane, and then "threaded" the cables into the clevis ends by rotating the inner cables themselves. I believe I used the ability to rotate the cable inside the sheath in order to fine-tune the cable throw...how far into or out of the clevises the cables went. The only thing I can think of is that in doing that, if there was any sort of burr or chafing going on inside the cable housing at the point where the cable end pivots, as I rotated the cables the burr would tend to slice the plastic. Now, it took hundreds of hours for the symptoms to start making themselves known, so I'm not convinced that this was the issue, but it's the best guess I've come up with so far.
Regardless, these cables are only $37 each from Van's since they're both the standard 60" length. I went and priced up cables from Aircraft Spruce's cable fabricator, and it was gonna be like $150 for both of them, as opposed to $74. And the other thing was that I'm already set up with that bulkhead that I fabricated behind the panel. This setup is "built around" these cables. If I switched, I might have issues to contend with in order to get it set up right again. I said screw it. I'm going with the cheap cables again. If they last another 820 hours then I got my 37 bucks' worth. Anyway, I ordered two new 60" cables from Van's. I suspect it's gonna be a week or more before I get the new cables (Van's is notoriously slow for getting small orders out), which buys me plenty of time to take my sweet time on this inspection and the quadrant project.
I managed to mess up the lower eyeball pass-through on my firewall where the throttle cable comes through. A little thread locker had frozen that sucker up. I gotta say, I really wish I hadn't designed these pass-throughs this way. I wish I had made a removable "panel" into which the eyeballs install, and then the panel can be installed or removed. That way, I could install the eyeballs on the panel while it's on the bench, and then just screw and seal that sucker right to the firewall. I considered making that mod now, but with the engine mount tube right there, and where I had penetrated the firewall, it wasn't gonna be ideal. Oh well. I just ordered a new eyeball fitting from Spruce. Another lesson learned. My second airplane is gonna be sweet!!
I hadn't taken a shot of the tailcone yet, so here's one for the record. I didn't do the inspection back here yet, but at first glance everything looks fine. I removed the ELT, because it's time to replace those batteries. The ELT batteries are now due for replacement by February 2008.
Continuing with the annual condition inspection projects...I have wanted to add stiffeners to the belly skins for a while. At times, when I'm flaring to land, just as the airspeed decays below about 50 mph or so, I hear a pop coming from the tailcone. It's one of the belly skins oil canning. A pilot who flew in low trail of me in formation noted that these two panels were pushing in when in flight. So I used some J channel and RTV'd it in place to stiffen this area.
I got the oil analysis back from the sample I sent out a week ago or so. The numbers were actually among the lowest ever. Good compression, good oil specs...looks like the engine is doing about as good as ever.
As you may have noticed by the dates on the last few pages, the plane has been down for over a week. I'm taking my sweet time with the condition inspection. Work has been busy, I've been doing a lot of writing for Kitplanes, and I just haven't had a lot of time to put into the inspection. Well, today I had a handful of hours to tinker.
You'll notice that my autopilot is removed. The glass face actually cracked. A few of the LEDs in the numeric display were intermittently going dark, so I was tapping on the face. I guess I tapped a little too hard! The glass cracked. I sent it back to TruTrak and they repaired it at no cost. Gotta love good service like that. You'll also notice the brand new DJM Manufacturing throttle quadrant is in!
After much fiddling and playing around with installation angles, I took some measurements and fab'd up a ridiculously simple mounting setup. I had hoped to use the existing nutplates in my instrument panel, and it ended up working out that way. The angle on the right side is just a piece of .063" thick 6061-T6 angle, bent open to about 105 degrees, and sliced at just the right angle to tilt the quadrant back at me a bit, toward the left side of the fuselage, and to tilt the bottom outboard. The angle bracket bolts right to the quadrant.
I'm glad I installed those three nutplates inside the F-704 covers on the side of my fuselage! I knew they'd come in handy someday. On the left rear corner of the quadrant, I just installed a little "twisted" piece of .063" stock. That third mounting point makes the quadrant fully rigid relative to the fuselage. Much cleaner than the old quadrant's mounting setup, which was only screwed to the panel (which allowed it to flex a bit).
I bent the throttle lever to the left a bit so it wouldn't be as tilted over. It's very comfortable this way.
You can see how easy access is to the clevis ends, clevis pins, and cotter pins. While I was getting the cables set up, and while I was measuring for and installing the rear mounting point, I had the quadrant on and off several times -- and having wide-open access to the connections sure made quick work of it. Some people have commented that they would cover the side, but I much prefer to have it open. Easy inspection, easy maintenance, and I like seeing in there.
Dayton asked me how I liked the new quadrant, and I had only positive things to say. He really wanted some sort of constructive suggestions, but I was hard pressed to come up with anything. Dayton is obviously a perfectionist, and he makes a terrific product.
Anyway, I've flown about 16 hours on the new setup as I write this. I wish I had just gone with this DJM Manufacturing quadrant from the get-go. Could have saved myself the hassle. There are all sorts of variations on this type of quadrant. Flat top, curved top, two lever, three lever, center mount, etc. I have always liked the feel of a quadrant, even in the Mooneys and Cherokees and stuff. If I was building an RV with center controls, I would definitely go with one of Dayton's quadrants. Good stuff!
I finished doing the condition inspection proper. I did the ELT batteries, belly stiffeners, throttle and prop cables, and the quadrant. Other than that, there really weren't any squawks at all. Just how it should be! I finished up by installing new carpet in the footwell area. Here's the old scribbled measurements I had taken last year.
I whipped up a CAD drawing of it for kicks and for clearer reference...
And here's the new carpet. Wooptedoo.
Since I had the carpet rolled out anyway, I decided to toss some carpet in the baggage area. I took some measurements in my usual chicken scratch format.
While I was doing the CAD thing for the front carpet dimensions, I did the rear dimensions.
Here is the master checklist (Word document) in case you want to adapt it for your own needs. It does not represent every single action that I perform on the plane, but it is a fairly thorough starting point. While I'm at each inspection point, I look at far more than just the subject.
Here is a complete cost report for this year's condition inspection, including the stuff I did last month on the engine condition inspection.
| Item | Vendor | Total Cost |
|---|---|---|
| 2" Heat System SCAT Tubing | Aircraft Spruce | $32.90 |
| Adhesive Heat Barrier | Aircraft Spruce | $17.40 |
| 4x UREM-37BY Spark Plugs | Aircraft Spruce | $63.80 |
| 4x NGK BR8ES Spark Plugs | Rock Auto | $6.44 |
| 2x CT Q-60 Control Cables | Van's Aircraft | $74.00 |
| Spherical One-Hole Eyeball | Aircraft Spruce | $31.20 |
| 2x AN3H-3A Bolts (for autopilot servo mount) | Aircraft Spruce | $0.70 |
| 2' of 1.5x1.5x1/16 2024T3 Angle | Aircraft Spruce | $15.00 |
| Push-On Edge-Trim Rubber Bulb Seal (canopy sides) | McMaster-Carr | $7.60 |
| Adhesive-Backed Rubber Bulb Seal (canopy front) | McMaster-Carr | $4.10 |
| Odyssey PC680 Battery | Sunn Battery | $80.09 |
| Total Cost: | $333.23 | |
Have I mentioned lately how much I love having a homebuilt airplane?!?!