I’ll get right to it… I think it was because one of the brushes in the heater combustion fan motor was severely worn, and when the motor / combustion fan did not run, the heater did not light.
Here’s a comparison of the old brushes and the new brushes I just installed:
(The 2 old brushes are on the left.)
This episode also includes the nose gear support structure rivets that needed to be replaced:
Now you might be wondering, “What kind of airplane is this?!”
It’s an Aerostar… a great airplane, but like all airplanes, it does take some maintenance.
And one area that needs to be inspected closely is the nose gear support structure. (The rivets in the above photo are in a bracket that supports the nose gear door rod shaft. The bolt below the center red arrow holds the left side of the shaft in place in the nose gear well.)
Listen to the audio to hear the complete list of squawks being addressed in this year’s annual inspection.
Have a great week!
The post “234 – Why the Airplane’s Heater Didn’t Light Last Winter” appeared first at AirplaneOwnerMaintenance.com
Not long ago, there was an oil leak on the right engine of a Cessna 414. The leak was significant enough to come out the louvers on the top cowling in flight. There was oil all over the rear inboard area of the engine, so the big question was, “Where is the oil leak coming from,” or “Where is the source?”
With so many possibilities, it was difficult to find the leak.
After multiple cleanings and ground runs, it was becoming more clear.
It was still however, hard to be certain. It seemed to be coming from the inboard forward base of the oil cooler. A flashlight and small mirror were somewhat helpful to see the area:
The borescope was also helpful to take a closer look:
Finally, after making the best evaluation I could without disassembling anything, I told the owner I was fairly certain the oil cooler was leaking… it seemed there might be a small crack in the oil cooler.
The annual inspection was already scheduled for this airplane, so it made a good time to verify the oil leak. The owner is an A&P, and he removed the oil cooler himself. I was hoping I had not steered him down the wrong path on this one!
He discovered it’s not an easy task to remove the oil cooler from his engine, but he persisted and got it done.
He sent me a text message and told me he had removed the oil cooler and when they first looked at it, he was not sure it was cracked. But after pressurizing it with 5 pounds of air pressure, the leak was obvious.
About the oil cooler, he told me “I tell you it was a job getting that off.”
The black circled area is where the crack was:
And here’s the really fun part… watch this video to see the bubbles confirming the source of the oil leak:
Here’s the engine after the oil cooler was removed… definitely “major surgery!”
This was the main maintenance topic in this week’s podcast, and we also talked about these items as well:
Aerostar voltage regulator adjustment.
Alternator charging system troubleshooting.
Our upcoming trip to Maui!
Thanks for listening, and we’ll see you in the next episode!
Here’s the short answer: Worn and contaminated brushes inside the alternator. Check it out:
My theory is that the excessive amount of carbon dust from brush wear was causing a short circuit situation between the brushes, and not allowing the field circuit in the alternator rotor to be properly energized for normal operation.
Here’s a comparison of the old and new brushes:
This story comes from a recent situation on the right engine of this Aerostar aircraft:
Since the alternator has externally removable brushes, it turned out to be a minimally invasive surgery to fix the problem. I cleaned the brush holder and also the slip rings inside the alternator, and after installing new brushes and reassembling everything, the alternator performed flawlessly.
Listen to the audio to hear the full story.
This episode also covers some of the email responses I received last week from some listeners, and here’s one of the highlights:
Glen sent me a photo of he and his dad in front of his Piper Cherokee… I love to see different generations enjoying aviation adventures together!
One more fun fact: Glen’s mom took her private pilot check ride years ago with Glen in the back seat of their Cessna 175 when he was 3 weeks old! What a great story!
Thanks Glen, for sharing some of your story with us!
This episode also covers a recent trip to Charlotte in another Aerostar, and the interesting routing we got from ATC on the way there… definitely some great IFR and ATC lessons to observe and learn from this one!
The Charlotte trip also sparked some conversation about twin engine charging systems, and paralleling issues that can happen… this situation is still in process, and I’ll try to give an update sometime in the future.
Finally, I had the privilege of joining Carl Valeri, Tom Frick, and Bill English on episode 301 “What is Your Most Challenging Approach” of the Stuck Mic AvCast. It was great fun talking about challenging approaches, both instrument and visual approaches.
I had an opportunity to fly in an Aerostar the other day… it was going to be a fairly long trip to the destination, with one fuel stop along the way.
As we climbed out of the Shenandoah Valley in Virginia toward the mountains to the West, we discovered the combustion heater for keeping the cabin warm was not working. After a brief conversation about what to do, we decided to keep going. Our two passengers seemed willing to tolerate the cold if they could still get to their destination. Thankfully, it was not as cold as it could have been for a January day.
We arrived at the destination on schedule and although we were at a small town airport, there was a small general aviation maintenance shop there, and one of the guys agreed to take a look at our heater.
As he removed the spark plug from the heater, the ignition lead came apart and a piece of it stayed down in the spark plug. Amazingly, he had the necessary part to fix the ignition lead, and the heater lit right up, no problem.
The trip home was wonderfully smooth and uneventful… and the heater worked!
Although we don’t hope to repeat that experience any time soon, we certainly made a memory that day.
I wish I had the freedom to tell you about the town we were at… it’s a cool name, and the AvGas price was great ($5.00 per gallon!)
Also in this episode, I talked about our recent trip to Greensboro NC for a service center update to our avionics system. Since the weather cleared up quicker than I expected, I managed to snag a few photos of the King Air the morning we dropped it off.
Scroll down for pictures of some things included in today’s episode.
Sitting in my truck the other day, I had a revelation. Here it is:
When you are having maintenance done on your airplane, Aviate, Navigate, Communicate, is exactly backwards.
Instead, it’s important to “Communicate, then Navigate, and finally Aviate.”
First, communicate.
TALK WITH your A&P or shop about the work you need done. Establish good communication right from the start, and maintain that communication all the way through the process. This way, you can hopefully avoid the surprises that could happen.
Second, navigate.
WORK WITH your A&P or shop to navigate through the discrepancies on your airplane, and develop a plan of action you both agree on.
Third, and finally, aviate.
FLY WITH your A&P!
Well… maybe not always, depending on the situation. BUT, in my opinion, your A&P should trust their work enough to be willing to go flying with you after working on your plane.
Here’s the point:
When something unexpected happens in flight, it’s absolutely important to “Aviate, then Navigate, then Communicate.”
But for maintenance, it’s just the opposite.
For maintenance, it’s vitally important to “Communicate, then Navigate, then Aviate.”
Communicate what you need done, and stay in touch through the process.
Navigate a clear plan of action WITH your A&P.
And when the work is done, you’re ready to AVIATE!
Here’s the Piper Cherokee that needed cowling latch repair: (Super nice-looking airplane.)
And here’s the Aerostar fuel quantity gauge that was discussed in this episode: (This was the successful reading after cleaning the wiring connection inside the right wing fuel tank.)
Now back to my little “rabbit trail” I mentioned early in today’s episode:
I did in fact, fill out the contact information on Matt Guthmiller’s website, to see if he would be willing to be a guest on the podcast sometime… we’ll see what he says. (At 19, he became the youngest person to fly around the world solo in an airplane!)
I can’t find the video I watched last night, but Matt has a ton of great videos on YouTube… and if you’re interested, by all means check out his website:
Corrosion in the towers of a magneto can cause high resistance, and the problem will be magnified as you go up in altitude.
This green corrosion could likely be cleaned up and it may improve some, but it may also indicate a good time to perform either a 500 hour inspection or an overhaul on the magneto.
Pressurized magnetos have an o-ring that seals the connection where the wiring harness attaches to the magneto. I found this one on a twin Cessna last week, while changing one of the magnetos.
Listen to today’s episode to hear about the details of this issue, and some things to think about for optimal magneto performance.
Thankfully, we got the twin Cessna running again, and the owner made 4 flights the very next day!
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