I haven’t been blogging as I’ve spent all my free time getting Woodstock through the first annual inspection since I got it up here in Seattle. Once a year every plane has to be inspected by a qualified mechanic to make sure it is in airworthy condition. I wanted to get my inspection done early in the year so I’d have my plane flying when the weather got good for flying. As with everything related to owning an airplane things did not got as planned. I have just completed the work on Woodstock to get checked out in my Ercoupe and finally really restart my pilot life. This post will be about what I’ve done and how it took so long.
The Annual Inspection
To save some money and to know more about my plane I decided to do an owner assisted annual inspection. Basically if you can find and A&P that will do it, the owner can do a lot of the work. Since most of the work is labor and a lot of the labor does not require specialized skills I felt I’m handy enough to take on the labor. First I needed to get time scheduled with the A&P. I found a fantastic A&P in the Seattle area named Stephen Baldwin. I found he was already being booked up so I grabbed the first opening he had available. It was a slot about a month away during the week. I confirmed and scheduled some time off of work. So we decided on March 13. In the mean time I was told to prepare the plane. I got a lot of conflicting information about what to take apart.
I also learned if the weather allowed Stephen will fly to my airport in his very nice Navion. His plane was once flown by NASA and was the personal favorite of a famous astronaut! Here is his beautiful plane:
So I found out I would need to provide complete access to the engine for inspection and compression test. I would need to allow inspection of the tail cone so I needed to remove the seats. Stephen would need to inspect the wings internally as well so I would need to removed all of the wing inspection port covers and the wing junction fairings.
- Engine Access
- Wing Access
- Tail Cone Access
Easy Peasy! Oh my oh my how the simple never is! Lets start at the front of the airplane. One engine item was compression test. This required access to the top and bottom spark plugs, Woodstock is unusual. Most Ercoupes have bumps on the top of the cowl to clear the spark plugs. These are easily removable to gain access to the plugs, Woodstock has rare short plugs in cans to allow the RF interference to be eliminated. You have to remove the nose bowl to get access to those plugs, To remove the nose bowl you have to remove the prop. My spark plug cans:
About those cans, you can see they take a special took to open. Here is the tool I was given with the plane. See if you can spot the problem. 🙂
Luckily my friend Olan is learning to weld and used it as an excuse to make a tool! He made me a very functional tool.
Here is the front of Woodstock with the cowling removed. Note, I just put the prop back on to allow the engine to be rotated.
Notice the fuel pump. We’ll get back to that later.
Then on to the wing. The FAA required that all early Ercoupes get fitted with under wing inspection ports to allow the spar to be inspected. At some point a few Ercoupes were found to have wing spar corrosion. These are round ports with covered with round metal covers held by spring steel clips. Here is what that looks like. You don’t think about them till you have to remove them and replace them! 🙂
Here are the access port covers as well as the wing attachment covers. The green material on the back of the wing root covers probably is the original material from 1946. There is also an interior cover for the trim lever. We’ll get to that in a while.
Here are the wing attachments with the covers off.
All this panels were attached with these impossible to remove screws. The slots were too narrow for normal screwdrivers and full of polish. I had to take a knife to clean the slots out to remove them.
Please note that that is not corrosion, that is old polish that needs to cleaned off. So after a weekend I had the prop off, the cowl off and the wing ready for inspection.
Tail cone battery access
I then moved onto the interior. I removed the seat cushions and seat back. The Seat back is held in by screws on the top and lacing on the sides. Here is a photo of the read interior of my plane. Notice the poor condition of the baggage “sack”.
I think moved back to the tail and removed the top faring to allow inspection of the horizontal stabilizer attachments. The evil screws were nearly impossible to remove and I nearly decided to cut the heads off to removed the panels. Here is the horizontal stabilizer with the faring removed.
So with the plane apart I decided to add some additional work. One wing tip strobe light did not work. I also wanted to add shoulder harnesses to my plane. The Ercoupe was not fitted with shoulder harnesses. A company called Alpha Aviation has a shoulder harness kit. So I ordered that. I would soon learn I would be ordering a lot of things! Here is the kit I ordered:
I also found a new flash tube for the wingtip strobe on Ebay. I place in AZ had one NOS in its original box at the bargain price of $100. So while I waited for things to show up and the big day that Stephen would look my plane over I started looking over my plane myself to learn more about it. I decided I should service the main gear. The Ercoupe has a main gear that uses an oleo strut to dampen bouncing and rubber doughnuts to be the springs. Over time they compress and need to be replaced. So I ordered a new set.
As I mentioned the old slotted screws were proving to be difficult so I ordered a new set of stainless screws with Philips heads! Everything I would reassemble I would replaced the straight slot screws with new Philips head screws.
The big day arrives!
So the magical day arrived. Stephen didn’t fly in that day. The weather was ugly. So we set about the business of checking out Woodstock. I showed him around the plane and we started on the engine. First we did the compression test. Stephen set up a compressor and one by one used a special fitting and pressure gauge to check the compression, All cylinders were were in the low 70’s and within 2 pounds of each other. This is great for a C-85 like I have cold. Stephen then removed the plugs and had be start on cleaning them. He then went on to look at the fuel pump. The FAA requires that every annual inspection that the fuel pump is inspected and the top bowl gasket replaced. OOPS, I did not know I needed to order a new gasket! He took the top of the pump off and it was very clean inside but it was clear the gasket had not been replaced for some time. Also the top spark plug washers needed to be replaced as well. Here are the old ones withe old fuel pump gasket.
The fuel pump gasket was particularly worrisome, Dennie the fellow that ferried Woodstock home from Compton said at one point the header tank seemed to not be refilling. Maybe this was why. The fuel pump may not have been working 100%. So a word about the original Ercoupe fuel system. The Ercoupe has a header tank in front of the instrument panel that gravity feeds the engine. The original Ercoupe had a single wing tank. A second wing tank was an option, Later on the second wing tank became standard, The fuel pump constantly feeds fuel from the wing tanks to the header tank. The header tank holds nearly 5 gallons so in theory when that the wing tanks run dry you have a an hour of fuel. There is a float to tell you how much fuel is in the header tank. Mine was worn out so I had decided to replace that as well. Here is the old float, Notice how worn the hole in the cap is. 70 years isn’t a bad service life!
A little more about the fuel pump. The pump is a variation of a pump first made for tractors! They are $1K new these days to you want to treat them carefully! Some folks have been known to but a pump that fits some common truck and then swap out parts as an alternative. Rebuilt ones can be had for around $500.
Stephen then moved onto the mags to inspect them and time them. They were perfectly timed and it turns out both of my mags have impulse couplers which is unusually. Most of the time only one mag has an impulse coupler, Impulse couplers allow the magneto to create a strong spark when they are rotating slowly. So mags were good. Stephen asked me to get a new fuel pump gasket and new spark plug washers. Those went onto my list to purchase. He looked over the plugs I cleaned and said they looked good, So we put them loosely back in the engine until it was all ready to put back together.
The last thing to look at was the air cleaner. Mine was filthy and looked like it hadn’t been serviced in years. The original filter is a round assembly that is supposed to be a snug fit into the air horn on the front of the plane and held in with a safety wire. Hmm, mine had no safety wire and was more than snug! We basically took it apart in place and Stephen suggested I could find the foam element from a Cessna to replace the paper element the old filter had. So some sort of air filter went on the list. The old air filter:
Then it was on to the wings. He got out a flashlight and a mirror and crawled around looking in all the inspection ports. He notice a few of the inspection ports had become loose and told me to get some contact cement to refashion the fixed rings that attached to the cloth covering before I closed the wing back up. He declared the wing good and did a walk around and focused on the tail of the plane. All looked good. He suggested I keep an eye on the bolt that attaches the control bell crank to the elevator horn as they can groove and fail. I made a note of that.
We then went to a place on Woodstock I knew needed some attention. The trim mechanism. The Ercoupe elevator trim is simple. It is a piece of solid steel music wire in the middle of an outer coiled wire housing, Someone said exactly like a choke on a lawn mower! Mine was seized. We tried to move it an ended up breaking it. OK, new cable went on the list of things to purchase. Stephen told me to oil the new one up a lot when I put it back together. The two ends were these simple specialized wire clamps. I made it a point to put them back someplace safe. Here are those clamps. More about them in the last installment,
Notice one of these has a locking nut and the other as castellated nut that is secured with a pin. The one with the lock nut was inside the plane in the lever and the pinned one was on the elevator trim tab horn. Here is the Ercoupe elevator trim tab after being modified to the “D” standard (higher gross weight).
We removed the trim lever cover and tried to free the cable. It wasn’t going to happen and we broke the end off the cable in the process. One more thing to buy. Here is the trim lever.
This is after I put in the new wire. That is the unattached end. So the trim tab has a small flat spring the presses it down. With no cable attached the tab is level with the elevator trailing edge. The cable pushes against the spring when put in the nose down position and is pulled by the cable for the nose up position.
Once we’d done all that could be done about the trim cable Stephen began to inspect the back of the plane. The inside of the tail cone looked great but the battery box could use some clean up. It was going to be a job to remove it, clean it up then paint it. So that went my list of things to do.
We spent some time looking at the logs. We decided Stephen would take them with him to review the FAA mandated AD compliance. Basically over the life of a plane the FAA learns things that should be checked or modified to make sure the plane is safe. A 70 year old plane like Woodstock had a number of things to be checked. Some were obvious like the wing inspection ports and the glass gascolator replacement and then bracing. Others are harder to detect and would require either documentation in the logs or filed with the FAA (for example there is an AD related to internal components of the engine that can’t be easily inspected). I was pretty confident as I had all the ADs related to my plane confirmed for compliance prior to the purchase. When I went to find that documentation I discovered I no longer knew where I put it! Face palm! No worries, Stephen said he’d look through the FAA records and I had the complete set of FAA records for the plane on DVD.
So we agreed that once I had the plane ready for the final inspection he’d come back, verify the work and then replace the propeller. The propeller has to be properly torqued and safety wired. He said he could get back the hangar easily as he came near the airport regularly after work. So had the “do it” list and the “get it list”. We figured a couple of weeks later we’d have the prop back on and I’d be flying! Well, “airplane weeks” maybe! 🙂
It would be April 19th before Stephen was back to look at my work and put the prop back on. And that would not be anywhere near when Woodstock would be ready to fly again.
So my lists,
- An Air filter element.
- New Spark plug washers
- Fuel pump gasket
- Trim cable inner wire
- New stainless screw set
- Center tank float
- New baggage sack, my current one was ripping and rotten
- Shoulder harness set
- New wing tip strobe tube/light
- New landing gear doughnuts
- Remove trim cable
- Remove old air filter element outer rign
- Replace all the wing inspection port covers
- Replace the wing joint fairings
- Replace the horizontal stabilizer front faring
- Remove and refurbish battery box
Optional to do list:
- Install shoulder harnesses
- Fix wingtip strobe lights
And in summary so far Stephen said he felt Woodstock was an excellent Ercoupe, So all good news so far!
Before I left the hangar I decided to remove the outer ring of the original air filter. That ended up requiring a slide hammer, 😦
So I took my list of things to buy and headed to Spencer Aircraft Supply, I figured they have some of the list. In the end, not so much, They had the spark plug washers. The rest of the stuff they had no idea. Oh well, off to the interwebs for some online victory.
I got home and ordered the trim tab wire from Univar and the new air cleaner element.
- Trim Tab Wire – $38.87
- Air filter – $83.01
- Center Tank Float – $127.86
The fuel pump gaskets had some trouble finding the right part number but finally took a chance and ordered two of what I believed were the right part.
Fuel Pump Gasket (ea) – $11.65
So parts were on their way.
That will be where I’ll leave you for this installment. The next post will be about what I learned about the quirks of the Ercoupe and my challenges with the strobe lights!
More coupeness to follow! Much is learned, blood is spilled and the sparks fly!