This experience was a good one! (At least looking back in 2020 hindsight.)

We had to dig deep to fix this one!

I was about to give up and started thinking it might be time to take the airplane somewhere else for troubleshooting and repair.

Thankfully Richard, our chief pilot, didn’t give up so easy and he encouraged us to dig deeper before giving up.

With the guidance of “Smitty,” an air conditioning expert at Stevens Aerospace in Greenville, South Carolina, we troubleshot and fixed a problem with our King Air 350 air conditioning system.

He told us we could access the center floor area just aft of the cockpit and ground pin #25 in the circuit board labeled “N1 SPEED / R ICE VANE SENSE” and this would fool the airplane into thinking the right engine was operating, so that we could troubleshoot the air conditioning compressor on the right engine.

We followed Smitty’s directions.

But after grounding pin 25 and powering up the system with the GPU, we found no voltage at the air conditioning compressor wiring plug. (We disconnected the red plug above the compressor to check for power to the plug.)

He then had us remove the right inboard wing leading edge to check the pressure switch in the high pressure line.

This was not the problem.

Smitty also told us there was a resistor and also a zener diode in the circuit.

During the process, my friend and coworker at Classic Aviation, David Kihlmire, said, “I think we should remove “that panel” referring to the side cowling panel on the right engine, just forward of the area where the air conditioning compressor was located.

And I’m glad he said that!

Here’s what we found:

The bottom wire was broken off the resistor!

Take a closer look:

After soldering the wire back onto the resistor, there was now power to the air conditioning compressor clutch, and we were confident the system was fixed.

David attached the gauges to the servicing ports in the nose gear well, and we ran the right engine… and YES!

The system operated normally.

When it was all said and done, it was truly a team effort, and a great learning experience.

And it was perfect timing to get the air conditioning fixed, because Summer time and warm temps are right around the corner!

Be sure to listen to the audio for this episode to hear the air conditioning story, and also my story about playing “Banana Grams” with my wife and daughter, as well as a story about repairing an oil leak on my Grasshopper lawnmower.

I wasn’t sure I wanted to tackle this oil leak myself, but after calling around and discovering all the lawnmower repair shops are backed up for weeks, I decided to go to YouTube University and face the challenge.

It was a 2 1/2 day project, among other things, but I got it fixed!

I had to remove the engine and disassemble it to replace the front crankshaft seal:

It was a mess behind the flywheel:

Lots of cleaning and a new crankshaft seal did the trick, and it’s back in business!

I’m grateful because one time mowing with the push mower was enough for me to realize I don’t want to do that every time!

All these experiences reminded me once again how worthwhile it is to take on challenging projects, even if they are difficult.

I hope you are encouraged to tackle something difficult in your life, if it’s something you’re interested in but might feel overwhelming.

Go for it!

The post “254 – Solving an Air Conditioning Mystery and Learning New Things!” appeared first at AirplaneOwnerMaintenance.com

This morning I felt the inspiration to record a podcast episode…

I got my hotel room set up with my computer and my microphone, and there it sat.

I missed the window of opportunity… for whatever reasons, I did not record.

And this afternoon, the inspiration was fading away.

And then I remembered something.

Often in the past, I’ve found that exercise is not only good physically, but it’s also good mentally and emotionally as well.

So I went down to the exercise room and ran some miles on the treadmill and did some pushups.

And it worked.

When I arrived back in my room, I seized the opportunity and recorded some thoughts about missing windows of opportunity, learning from them, and continuing on.

If you listen to the audio for this podcast, you’ll hear about the following:

Hope you enjoy the episode!

And remember, don’t get bogged down in the missed windows of opportunity behind you…

Instead, look for the open windows of opportunity in front of you now, and go for it!

And if you have a story to share, please click the button over on the side of the website and leave me a voice message… I’d love to hear from you.

(If you’re in a hurry, scroll down to see the tiny little chafed wire that caused this whole conundrum.)

Now here’s the story…

This landing gear relay breaker had been popping intermittently:

It came time for annual inspection and we decided to replace the breaker with a new one, in order to rule out a faulty breaker, and attempting to minimize long and frustrating labor for troubleshooting.

Good thing, because as it turns out, there was a loose screw in the landing gear motor breaker next to this one, which would not have been discovered if we had not replaced the relay breaker… check out the loose screw:

It was obvious some arcing had occurred due to the poor connection:

Unfortunately, tightening the screw in the 30 amp motor breaker, and installing a new 5 amp relay breaker, did not fix the problem.

Back up on jacks for more troubleshooting:

Todd, the airplane owner, posted in BeechTalk about the situation, and we got some good feedback.

Meanwhile, I took a good look at the wiring in the main gear wells, especially the squat switch wiring… no issues found.

So I called the American Bonanza Society (I love their tech support, and it always reminds me of the exceptional value of being an ABS member, even as an A&P/IA.)

Curtis Boulware discussed the wiring diagram with me and pointed me to some things to check:

Aha! Now we were getting closer.

After removing the circuit board from its mounting position and disconnecting the P1 plug, the relay breaker no longer popped when gear was selected up.

But why?

I was beginning to wonder if we would need to have the circuit board repaired or replaced… and who knows how much one of those would cost!

And then my eyes landed on something that did not look quite right.

It was a spot on a tiny little wire.

After closer examination, sure enough, this little wire had chafed through the insulation and some of the internal strands of copper wire were visible:

But what had it been chafing on?

Finally, I saw it… a burnt spot on the sidewall of the airplane:

Perhaps this wire had been chafing for many years and finally wore through the insulation. (The little loop of wire had not been adequately secured into the wire bundle, which allowed it to touch against the aluminum sidewall of the fuselage.)

It was the little G43A20 jumper wire that connects 2 pins in the P1 plug.

After removing the bad spot in the wire, splicing it back together, and securing the wiring, the landing gear system worked perfectly.

And if you’re curious like me, here’s a peek inside that circuit board under the copilot panel near the outboard rudder pedal:

I’m glad we didn’t have to replace that thing!

(To hear the full story on this one, be sure to listen to the audio for this podcast episode.)

The post, “252 – Why Does the Bonanza Gear Relay Breaker Pop?” appeared first at AirplaneOwnerMaintenance.com

Bennett contacted me awhile back to see if I could lap an exhaust valve for him.

The #4 exhaust valve showed a very uneven appearance when viewed with his borescope.

Bennett flew in to KSHD one morning and we got started.

Before lapping, we checked the cylinder compression and it was 29/80… not good.

Here’s what the valve looked like:

We got to work and lapped the valve.

When we were happy with the progress, we reinstalled the exhaust valve in the valve guide and installed new valve springs and a new rotocoil, to help ensure the valve would rotate properly and provide the best possibility for a good seal between the valve and the seat.

After running the engine, we rechecked the compression, and were very pleased… it was 74/80!

Amazing!

But there’s more…

Several weeks later, Bennett emailed me, and here’s what he said:

“Dean, I am so excited I am emailing from my hangar… Looks like lapping worked great! After one flight down to Florida and back… about 3.5 hours each way, the #4 exhaust valve looks vastly improved. See before and after pics attached. Much thanks!”

And here are the before and after photos he sent:

BEFORE:

AFTER: (and keep in mind the following photo was after only about 7 hours of engine operation.)

I’m confident this exhaust valve has been rescued, and will quite possibly run normally for many more hours.

It’s always nice when we can solve these valve problems with “laparoscopic surgery” (lapping a valve in place) instead of “major surgery” (removing a cylinder.)

There’s more to this story, but I’m not going to type it out here… you can listen to the audio for this podcast and hear about the magneto issues we solved on Bennett’s engine as well.

(The magnetos on Bennett’s engine are challenging to work on due to their location and all the stuff around them, but with some persistence, it’s doable.)

Thanks Bennett, for flying down to SHD.

It was nice meeting you and working with you!

The post, “251 – Bennett’s Exhaust Valve Rescue on his Cessna TTx” appeared first at AirplaneOwnerMaintenance.com

If you look closely in the photo above, you can see my friend Chris, smiling.

It was the day he arrived at Classic Aviation (KSHD) to begin his annual inspection with me.

Chris is not only an airplane owner and pilot, but he’s also a certified airplane mechanic as well.

I was very happy to have him help with the process as much as possible.

As I worked through the inspection, I found the control cable tensions needed some adjustment, including the rudder cable tensions.

As I began to tighten the left and right rudder cable tensions evenly so as not to disturb the rigging, I encountered a problem.

The left cable turnbuckle bottomed out in the turnbuckle barrel, and there was no more ability to tighten the cable, but I had not yet reached the cable tension spec in the maintenance manual of 85 pounds, plus or minus 5.

Yes, this is a high tension, but it is what the manual says.

You can listen to the audio for details of how we resolved the issue, and how I got help from my friend Kenneth who previously worked at Classic Aviation.

The short story is that we went through extensive rigging of the nose gear steering system, the rudder pedal bars, and the rudder cables, and finally got things set, with 80 pounds on the rudder cables.

When the annual was completed, we had fixed a bunch of other items as well, and hopefully Chris will be good to go for another year with no maintenance interruptions, as much as possible.

He even sent me some photos of the day he flew his sons down to the Outer Banks of North Carolina and visited the Wright Brothers Memorial! Thanks Chris!

The post “Frustrations with Piper Rudder Cable Tension – Episode 250” appeared first at AirplaneOwnerMaintenance.com

Today’s episode is about Pat’s Mooney, and how we sealed up some exhaust leaks.

And it’s a fun story because Pat has become a good friend… check out the above photo where he’s showing his airplane to my grandson Spencer

Spencer and my daughter McKenzie stopped by the shop one day when Pat and I were working on his Mooney 252 (M20K.)

And if you’ve listened to the Airplane Owner Maintenance Podcast, you’ll likely remember that it’s McKenzie’s voice in the podcast intro and outro… thanks McKenzie!

Pat flew his Mooney from Wisconsin to Virginia for his annual inspection, and he hung around for several days to work with me on his airplane… I love airplane owners like Pat!

I love working with the “Pats” of general aviation because they tend to have some or all of the following traits:

And that pretty well describes Pat, so we got off to a good start on his inspection.

One of the squawks I discovered was 5 of the 6 exhaust flanges had small leaks at the gasket area… we found this while doing a pressure test on the exhaust system. Here’s one of the flanges that was leaking:

This engine is a Continental TSIO-360 and has 2 thin stainless steel gaskets P/N 630365 on each cylinder.

Here are the old gaskets I removed, along with one stud that backed out and had to be replaced with a new one:

I’ve found there is significant confusion out there about how these gaskets should be installed.

One side has a raised area, or a bump on it, and the other side has a recessed, or concave area.

As I’ve researched the internet (sometimes a not-so-good place to get good information,) it seems a fair number of people think these gaskets should be “nested” together for installation.

That is, put both gaskets in the same direction to they fit together, and then install them.

I wanted a definitive answer, so I called Continental.

Vadin was very helpful and explained it to me this way:

“You want to create an air pocket between the two gaskets.”

This means put the concave or recessed side of the two gaskets toward each other and this creates the air pocket.

Then, as you torque the exhaust nuts and squeeze the gaskets together, the bump on the top gasket is up against the cylinder flange, and the bump on the bottom gasket is down against the exhaust riser flange, and in this way you can hopefully seal up any small imperfections on the surfaces and get a perfect (or nearly perfect) seal.

Also, there is another type of gasket that can be installed on this engine… it’s the “blow proof” gasket made my Rapco, P/N RA970.

Here’s the visual difference between the two types of gaskets (the thin ones on the top and the thick, blow proof one on the bottom):

I asked Vadin at Continental about these, and he could not officially endorse them, but he also acknowledged that some people seem to have good success with these thicker gaskets.

So, after discussing the situation with Pat, we decided to go with the thicker, blow proof, RA970 gaskets.

Prior to installing the gaskets, I had carefully sanded all 6 exhaust riser flanges flat and smooth so as to get the best seal possible. Here’s a photo of the exhaust system before sanding the flanges:

I carefully installed the new gaskets, and torqued all the nuts with the studs properly lubed with engine oil.

I was excited to do another pressure test and was confident about the results.

I was sorely disappointed.

Five of the six flanges still had small leaks.

Back to the drawing board.

I texted Pat and notified him that I thought we should try the other type gaskets and see if we could get a better seal.

He agreed.

So, I reluctantly removed the thick RA970 gaskets and installed two each 630365 thin gaskets (properly positioned) on each flange and retorqued everything.

Time for another pressure test.

It wasn’t perfect as I had hoped, but it was very acceptable.

Three of the flanges were perfect with zero leakage.

The other three were nearly perfect with only very small bubbles forming slowly at one side of the flange during the pressure test.

I’m satisfied with this… and as I thought about the whole situation, I suppose you could buy a whole new exhaust system for the engine in hopes of getting a 100% perfect seal, but I don’t think that’s necessary in this situation.

I also realized that if this was my personal airplane, I would feel the same about it, and I would fly my family in it with great confidence.

Be sure to listen to the audio for this episode to hear the whole storyl

And after all that, I’m EXHAUSTED!

But it’s been totally worthwhile, because Pat is such a great guy to work with!

Thanks Pat, and I look forward to returning your airplane to you real soon!

The post “249 – An EXHAUST-ing Mooney / Continental Story” appeared first at AirplaneOwnerMaintenance.com

Last Monday, I lapped the #5 exhaust valve on a Continental engine.

But more importantly, I met the owner / pilot of a Turbo Centurion, and now I’m happy to call him a good friend!

Thanks for flying all the way up here Mark!

Here’s the story:

Mark had been a little concerned about the #5 exhaust valve, not because he was having any particular trouble with it, but because the borescope photo showed a slightly irregular appearance.

And being proactive, Mark decided to do some research.

That’s when he found me, and some of the information I’ve published to help airplane owners understand borescoping, exhaust valve lapping, and other useful pieces of information you often won’t find in the “maintenance manual.”

Mark’s local shop had indicated it would be a good idea to keep an eye on the #5 exhaust valve, and if it continued to be a problem, the cylinder may need to be removed for a repair or replacement.

Some years ago, I would have had similar thoughts.

But not today.

In the past 5 years, I’ve rescued many cylinders from premature removal, especially on large bore Continentals… and I was hopeful we could remedy Mark’s situation as well.

Instead of removing cylinders in situations where the exhaust valve is showing beginning signs of burning, or the compression is dropping into the 50’s and 40’s and below, I now consider the first option of LAPPING THE EXHAUST VALVE WITHOUT REMOVING THE CYLINDER, AND INSTALLING A NEW ROTOCOIL.

Mark was interested to learn about this process, so we agreed on a plan for him to fly his airplane from North Carolina to the Shenandoah Valley of Virginia for some not-so-invasive surgery on his airplane engine.

Soon after Mark landed, we rolled his Cessna T210 in the shop and got to work.

I won’t bore you in this post with all the details, but we lapped the exhaust valve and were both pleased with the progress along the way and with the end result.

Take a look at some photos showing the lapping compound at work, and the nice, shiny sealing band that’s developing on the edge of the valve.

An excellent sealing surface, along with a new rotocoil on the valve, will help to ensure it rotates properly during operation, thus minimizing the chances for a burning exhaust valve which will shorten it’s lifespan if not remedied.

When the process was completed, we flushed the lapping compound out the bottom spark plug hole and sprayed some LPS-2 in the top spark plug hole and dispersed it with compressed air in an attempt to keep the cylinder wall lubricated during startup, after which the engine lubrication system would take over and do its job.

During reassembly, we installed a new rotocoil P/N 629117-1 on the exhaust valve and reassembled all the parts that had been removed.

You may ask, “Why do we need to install a new rotocoil?”

Great question.

And to answer the question, some photos will help.

When you cut a rotocoil apart, here’s what you’ll find: two halves, a special washer, and a long spring laying on its side.

Every time the valve stem is pressed down by the rocker arm, the rotocoil makes the valve rotate just a little. This action helps prevent hot spots on the edge of the valve, and keeps the sealing surface in tact between the valve and the valve seat.

Over time, the spring gets a flat spot on it which decreases its ability to make the valve rotate.

Here’s a close-up photo of the flat spot on the spring:

Eventually, the spring can break into many pieces if the coils get too thin at the flat spot.

For this reason, and because rotocoils are very reasonably priced, I always install a new rotocoil when I lap a Continental exhaust valve.

We completed the project, Mark ran the engine, and we re-checked the compression. It was excellent at 75/80, a stellar number!

I’ve had very dramatic improvements in compression numbers after lapping valves (like from the 30’s or 40’s to the 60’s and 70’s.) This time was not as dramatic as Mark’s #5 compression was 71/80 before lapping. But it was still very worthwhile doing in order to prevent any further irregularity in the sealing capability and appearance of the valve.

Mark was being very proactive and planning ahead, and I applaud that!

Sometimes people let these valves go too far, and then there’s no choice but to remove the cylinder.

But if caught early, most exhaust valves can be saved from further burning.

Mark, it was great to work with you, and although I don’t wish for you to have any airplane troubles, I do hope we can work together on your airplane again sometime soon!

The post “248 – Mark’s Cessna T210 Exhaust Valve Story” appeared first at AirplaneOwnerMaintenance.com

Everything looks normal in this photo, right?

What we can’t see from this angle is the fact that the brake disc has broken in two pieces!

Check it out:

Here’s the story:

The pilot landed the Piper Cherokee, and after a successful landing, something gave way on the left brake, and it became ineffective. Now we know why.

It’s definitely time for new brake discs, and this airplane will soon get new APS164-02000 Blacksteel brake discs that are corrosion resistant.

It will also be a good time to replace the worn tire on this wheel.

After some research, I discovered a retread Goodyear Flight Special II (like the airplane currently has on it,) is about half the price of a new one, and can be purchased directly from Wilkerson Tire Company here in Virginia!

And when I called them, a real live knowledgable and helpful person answered the phone… it was truly a great customer service experience (it was Mckaellen Wilkerson, a fourth generation member of the team there.)

I love supporting quality family businesses whenever possible, and Wilkerson appears to be one such business.

Here’s a link for their website if you want to check it out:

https://www.wilkersonaircrafttires.com

Thanks Mckaellen, for your excellent help!

In this podcast episode, I also shared two emails I received recently.

One was from Troy, who had some very helpful and interesting things to say about the last episode about single engine RG Cessna airplanes. Thanks Troy, for the reminder that if one of these airplanes is not high enough and the gear is retracted, it can actually lift the airplane right off the jacks… yikes!

Be sure to listen to the audio to hear the rest of his email.

The second email I mentioned was from Fabien.

He and his family moved to the US awhile back and they fly a nice V35B Bonanza. He had a question about where to get his ruddervators stripped and repainted due to some corrosion that has been developing.

If you have any excellent recommendations for V-Tail Bonanza ruddervator paint work, you can contact Fabien directly at the following email:

fabien.turpaud{at}icloud{dot}com

Along with his paint question, he also shared some really great photos and gave permission to include them here:

The filiform corrosion on the ruddervators is not critical yet, but Fabien is being proactive about making a plan to remedy the issue as soon as reasonable.

Hopefully we can find a good solution for Fabien to get his ruddervators repainted with minimal down time so he can continue the adventures with his family!

The post, “247 – Brake Failure After Landing” appeared first at AirplaneOwnerMaintenance.com

This story begins with a squawk from the owner. It went something like this:

“When I fly my airplane, on the first landing gear retraction, the gear begins to move and then the “gear pump” circuit breaker pops. After I reset the circuit breaker, the gear retracts and extends normally with no further problems the rest of the trip.”

Weird…

What could be wrong?

It was my job to figure out what was going on.

I put the airplane on jacks and selected “gear up.”

Sure enough, the gear began to move and after a short time, it stopped mid-travel and the “gear pump” circuit breaker popped.

For once, the problem happened just like the airplane owner had reported.

I checked each gear leg for any binding, and everything appeared nice and free to move.

After evaluating and thinking through the situation, I decided it was a reasonable possibility there was an internal problem in the electric motor on the landing gear power pack.

I removed the motor and quickly discovered it was full of debris. Take a look at the brush housing:

Amazingly, a can of contact cleaner and some compressed air produced a quick transformation… and the brushes actually had lots of good material remaining:

The commutator segments were in similar rough shape when I first disassembled the motor:

But some Scotch-Brite, contact cleaner, and compressed air freshened up this area as well:

The armature housing also had a large amount of debris to be removed:

I didn’t think to take a photo after cleaning, but it turned out very nice as well.

Before disassembling the motor, I thought we might end up replacing it with an overhauled one.

But after seeing how well the motor was made, how simple it was, what good condition the brushes and other parts were in, and how easily it cleaned up, I realized it would likely be good to go for a long time, and I decided to reinstall it.

And here’s the motor after reassembly, along with one of my grubby hands

Here’s the landing gear power pack area that’s accessible near the copilot’s feet after removing the little plastic cover on the side of the console: (these photos are before I reinstalled the motor.)

Before reinstalling the motor, I put some black electrical tape around the end seams to keep the housing from coming apart (there are 2 long 1/4 inch bolts that go through the length of the motor and attach it into the drive area on the power pack.)

After everything was back together, I ran the landing gear, and it performed flawlessly!

Now, the real test will be to see what happens the next time the owner flies his airplane. Until then, I’m hopeful for a good report.

Sometimes, we do need to just replace parts on airplanes… but sometimes, we can be a real mechanic, and dig in and repair an existing component!

In this case, I’m figuring I saved this owner a chunk of change on this repair.

One final item: when the airplane was in the shop, it became really obvious the right brake caliper was leaking… check it out:

A couple new o-rings and some brake linings took care of this squawk as well.

Now it’s time to go fly!

The post, “246 – Parts Changer or Real Mechanic? Cessna-210 Landing Gear Motor Story” appeared first at AirplaneOwnerMaintenance.com

The week I’m talking about here was almost too full!

But I wouldn’t change a thing.

A real highlight was taking my Pennsylvania cousin for a short flight in a Piper Cherokee:

From Sunday to Friday, I had the following opportunities:

Also, during the Bonanza inspection with my friend Mike, we adjusted the fuel quantity circuit board adjustments a bit to make them indicate accurately when the tanks are full… the maintenance manual had excellent instructions which also agreed with the very clear information on the circuit boards themselves located just under the top center part of the instrument panel glare shield… here’s a photo:

It was an awesome week, and I recorded some thoughts about it for at least a couple reasons:

One, I hope you might find some inspiration and encouragement in it.

And two, I wanted to document the week a bit to help me remember it in the future.

So… if you’d like to hear more about the adventures of this particular week, listen to the audio for this week’s podcast.

Thanks, and have a great day!

The post, “245 – A Crazy and Amazing Week!” appeared first at AirplaneOwnerMaintenance.com