Second annual condition inspection wrapped up

Finally finished last few items for my annual inspection / maintenance today. 205 hours. Few tidbits:

1) Did compression test for first time per Rotax manual. Pretty much a waist of time as all the cylinders came in +98%. Amazing little engine.



2) Removed and shipped carbs to Lockwood for disassembly/maintenance at 200h, again per Rotax. Took lots of pictures removing them to be sure and get all the H/W correct for re-installation. They have always performing flawlessly for me, but as I removed them I did notice yellow stains on the sides of the choke assembly attach screws (both carbs). Had never noticed this before. Looks like dried fuel. Anyhow, they came back nice and clean from Lockwood but will pay more attention to them going forward whenever I remove the cowl.



3) Cleaned out the oil tank for the first time. Generally only use mogas (+80% of the time) and for the last 100 hours whenever I was forced to buy 100LL I began adding some decalin. Also err on changing oil about every 35-40 hours over last couple of years. Very minimal sludge on the bottom of the tank as you can see so I'll probably continue to clean out the tank at 200h intervals with this level of 100LL use.



4) Spark plugs are only about 100 hours old and the brown color looks like they are in good shape - just checked the gaps and reinstalled them.



5) Removed the tires from the hubs and rotated them to put the better tread on the outside of each wheel. (fun job!) Picture below is the pre-rotation view. No cord was showing on the areas where the tread was worn down so they should be good like this for at least another 100 hours (hopefully more) Replaced brake pads as well. (I am clearly too heavy on the brakes and go through pads at a higher rate than I'd like to admit - when it was a rental 172 it didn't matter, but now it does!)



6) Found a missing rivet on one of the doublers on the fuselage bottom (near com antenna). Now I don't know how many times I've crawled under that plane (and other builders, inspectors, painters too....) and none of us caught that. Go figure. Also saw a lot of overspray from the paint shop that covered wires, fuel lines, etc... Disappointed they didn't cover up these openings more carefully. Just looks sloppy. Not sure I'll ever have to splice into these wires/lines at these specific locations, but if I did, they are all the same color. If I every get an aircraft painted again, this is something I'd make sure was discussed in advance.



7) Finally, did weight/balance for first time since she was painted. Loaded up cabin with all the items I virtually always fly with (eg. headsets, iPad mount, fire extinguisher, First Aid kit, some tools, oil, decalin, overnight cover...) EAA chapter scales round to nearest 10lbs which isn't ideal. She came in at 800lbs! At DAR inspection two years ago I measured 760lbs with the same scales. So in reality the +40lbs could be anywhere between 30 and 50 but ouch...Makes sense if the paint added about 20 and all the other items probably add at least 20. She gained more weight in the last two years than I did! Might be time to reconsider some of my "standard" items. Like my interior, but that too has a cost...


Anyhow, good inspection, maintenance is fully uptodate. Really looking forward to flying again!

I'm curious Brent, did you get any feed back from Lockwood regarding the condition of the carbs?
I'm reluctant to take that step when everything is running well!
Thanks for the report.

I'm with Lee on that one. I'm at 430 hours and haven't messed with my cabs except to balance them. Next year I plan a carb tear down during the rubber replacement.

"I am clearly too heavy on the brakes and go through pads at a higher rate than I'd like to admit - when it was a rental 172 it didn't matter, but now it does!"

You had nosewheel steering to help you in the 172. For comparison's sake, I made it to 170 hours on mine and still had a little room on the wear indicator - I'm sure 200 hours was the most I would have gotten had I waited.

If you do a new weight and balance for your aircraft, making the appropriate log and POH entries, I would not recommend doing it with all of the extra stuff in the plane, such as headsets and misc other items.
W&B is supposed to be calculated using the empty weight of the plane so that pilots can calculate w&b considering fuel, baggage and pilot/passenger weights for each flight.
All of those extra items you weighed may or may not be in the plane or may not be stowed in the same location which will affect w&b and could cause calculations to be inaccurate.
Is it a big deal for an rv12, maybe not, but why not do it right?
If you just weighed it to see for your personal information, that's one thing, but if it was done to adjust for paint weight and to make new log entries, you should drain the fuel and take all the stuff that's not permanently attached out, before weighing.
Just my two cents.

Another suggestion......

I wouldn't let my tires get that thin. If you let it wear to the cord, the air isn't far behind. These tires are VERY thin after the tread.

Appreciate questions/feedback.

Carbs. Didn't get specific feedback from Lockwood (just the fairly generic logbook sticker) Will send them a request for more detail that the sticker says they have on file. There is a gasket under the choke housing that I understand was replaced as part of this 200h servicing. I just assumed if there is a gasket, there is a chance for leaks.

[NOTE: Did get brief comment from Lockwood A&P tech who worked on the carbs. "Nothing unusual noted during servicing ... the stains are common, from fuel, and do not come off...]

Engine definitely ran rough on first start after reinstalling them. Went back through the mechanical and pneumatic balancing process and eventually got them back to normal (pre-removal)

Weight and balance. Did the W&B more of interest to me as I had the fuel tank drained. See your point that several of the optional cabin items can move around affecting the CG. Sill have the scales so probably should redo with everything optional removed and then add that to the logbook.

Tires - I've learned that everyone has an opinion when it comes to tires. Actually an A&P happened to drop into my hanger when I was removing the wheel pants and I had him look at the tires. In his opinion, for what its worth, they were acceptable. But I do see Mel's point and will probably go ahead and order new ones. Not worth pushing my luck.

In your second photo .......

The molex connector has some pretty stressed wire coming out of it. I think that's the main fuse bus power wires. I would look at relieving the stress on those as the exit the connector.

PilotBrent said:

Tires - I've learned that everyone has an opinion when it comes to tires. Actually an A&P happened to drop into my hanger when I was removing the wheel pants and I had him look at the tires. In his opinion, for what its worth, they were acceptable. But I do see Mel's point and will probably go ahead and order new ones. Not worth pushing my luck.

Click to expand...

Don't get me wrong. There's nothing wrong with rotating tires. I just wouldn't let them get that far before rotating them.

Next time you get ready to throw away a tire, slice it open at the thinnest point and see just how thin it is. These tires are 4 or 6 ply "rating". They are NOT 4 or 6 plies.

Very useful report, thanks for spending time doing it (now I feel guilty not to have done it with more details). We all learn a lot while doing our annual. Sharing on this forum what we learn not only benefits all but also induces comments and questions that deepen the understanding of what we observed and shared as shown in this thread.

PilotBrent said:

Weight and balance. Did the W&B more of interest to me as I had the fuel tank drained. See your point that several of the optional cabin items can move around affecting the CG. Sill have the scales so probably should redo with everything optional removed and then add that to the logbook.

Click to expand...

What you've established in this exercise is a very important number - Basic Operating Weight, or BOW. This is the handiest number that we, as pilots, can have available to us.

A true Empty Weight, as defined by the FAA, is not particularly useful to us when we're standing on the ramp on a hot day, trying to figure out how much fuel we can add to the tank to stay within gross weight and CofG limits.

By contrast, the BOW takes away all the math associated with adding engine oil etc etc. The BOW is the "flying weight" of the airplane - add to it your pilot and passenger weight, fuel and cargo, and you've quickly and easily arrived at your current aircraft weight.

When I calculate BOW I also add my own weight (+10lbs for winter ops) so the only variables are passenger, fuel and cargo. Knowing your BOW means you'll have fewer opportunities to make errors when calculating current aircraft loaded weight and CofG.

Rotax 912 Spark Plug Condition

I'm going to hijack this thread, and add my spark plug pics and ask the experts who have done more work on replacing and examining 912 plugs to weigh in and see if I have any problems here:

They look normal IMHO.

Canadian_JOY said:

What you've established in this exercise is a very important number - Basic Operating Weight, or BOW. This is the handiest number that we, as pilots, can have available to us.

A true Empty Weight, as defined by the FAA, is not particularly useful to us when we're standing on the ramp on a hot day, trying to figure out how much fuel we can add to the tank to stay within gross weight and CofG limits.

By contrast, the BOW takes away all the math associated with adding engine oil etc etc. The BOW is the "flying weight" of the airplane - add to it your pilot and passenger weight, fuel and cargo, and you've quickly and easily arrived at your current aircraft weight.

When I calculate BOW I also add my own weight (+10lbs for winter ops) so the only variables are passenger, fuel and cargo. Knowing your BOW means you'll have fewer opportunities to make errors when calculating current aircraft loaded weight and CofG.

Click to expand...

Here in the US "basic empty weight" includes engine oil, unuseable fuel.

John,

Some of mine are tan, and some are a darker brown. I toss them every year and go with new plugs. At the going rate it seems like a cheap way to go. I didn't see anything on your pics that is different from what I have seen in 3 annuals.

Rich

BobTurner said:

Here in the US "basic empty weight" includes engine oil, unuseable fuel.

Click to expand...

The true power of the "Basic Operating Weight" is that it includes all the "stuff" you normally haul along with you. I don't fly without my flight bag, so that is included in the BOW for my airplane. Same for headsets, tiedown equipment and basic survival equipment. Having all these weights rolled up into one handy number makes calculations on the ramp so much easier.