So the initial part of the annual inspection we complete. I needed to chase down some parts and begin to do the worked we decided to do before getting the plane signed off. I also had some things I had decided do to my plane that weren’t part of the annual but it seemed like the right time to do them. I’m maybe taking some of these out of order from when I got to them but they were part of the work I needed to do.
The first thing I wanted to do was fix the strobe light on the left wingtip. When I bought my plane I was told the strobe on one wing did not work. I was told it was probably the flash tube went bad. I could see in the lens that their did look like there may have been moisture in the light and the tube could be bad.
My tip lights are Grimes navigation lights that have been modified to have a standard Whelen strobe light fitted. Here is a picture of the tip unit.
See how the bowl seems clouded. Also see how the unit is held together with rivets. So I drilled out the rivets and found that there was a Molex connector on the strobe light. As I looked more I realize that the unit could not be totally removed from the wing as the connector was too large to fit through the hole in the Grimes light. So I decided to cut off the connector and find a new connector that would fit through the hole. The original wire had been covered with some sort of rubber material and the old wire did not allow for me to easily strip and then fit a new connector. Ugh, I was going to have to splice in new wire at the end of the existing wire. So I ordered some appropriate aircraft approved shielded 4 conductor wire from Aircraft Spruce. When it arrived I got a friend (thank you Olan!) to help snake out the existing wire through one of the open wing inspection ports. Then I trimmed back the ends of the existing wire, soldered and used heat shrink tubing to insulate the splice and then pulled the new longer wire back through the Grimes light. I had removed the entire Grimes assembly to drill and tap the strobe light dome hold down holes. A 6/32 screw seemed a lot more practical than the rivets used before. I had also found a new strobe tube. I found a slightly differently shaped molex connector that would fit through the hole at the base of the Grimes unit. More soldering and crimping in the connector pins and it was all ready to test!
So I’d love to say it all worked beautifully and I immediately moved on to the next task. No, we are talking about working on a classic airplane. Nothing is so simple! My first guess was somehow or other I had hooked up the strobe tube wrong, Spent some time verifying the previous connection (making sure I’d properly matched the wire colors). I could find no problems! I then tried to trace the wire from the tip light to the strobe light unit. It was run in the aileron channel and I could trace it all the way to the wing attachment point. Aha! A plug! Surely this newly discovered plug was the problem! No joy there. After inspection there was no problem there. Maybe it was the strobe power unit! I’ll check that. Here is a picture of the strobe power unit.
So I reversed the wing plugs and the other strobe worked fine. So the power supply was correctly firing both wing plugs. I was at day two of this project and getting frustrated. I finally decided that I didn’t expect to be flying at night any time soon so not having both strobe lights working was not a problem.
I’d also done some research and I learned that legally my plane did not require strobe lights. Do to its age all it required was the navigation lights. OK, I’d verify that the navigation lights worked and I’d find the strobe light problem some time later. So lets check those navigation lights. They will work for sure, right? NOPE, the left tip light was dead! Arrgh!! So I looked to see if I understood how the plane was wired. I looked at the switches to make sure everything was being turned on. No, I was operating the switches correctly. What could be wrong. Again I double checked the wiring. No problem found. I decided to go back to the Grimes unit and tie off all the strobe wires and verify the the navigation lights were correctly wired. I verified that and still no function! In the meantime I found these two fuses! They looked important, maybe one of those was the culprit!
So I pulled out the fuses to see if they were good. Eureka! One was bad, surely this was the problem! I had found an old fuse container in the pocket of my plane when I went through it after it arrived. So I put in a good fuse and turned on the nav lights, Starboard light, good, port light, dark!! OK, time for a break and a beer.
I sat down with a vold beverage and began to look through the log books, I was sure somewhere there was a diagram of the update schematic for my plane. It had been rewired at some point for the radios and other flight instruments. Hmm, no fuses shown, Of course it had long back been upgraded with circuit breakers. I also learned I had a “taxi” light and a “landing” light on separate switches. I will use that to my advantage in the future. A planned upgrade is to upgrade to LED landing lights and add a “wig wag” controller to make my plane more visible in the daytime.
So I discovered the mystery fuses no longer had a purpose. Woodstock continues to be the plane of mystery! But I still had a dead nav light. What could it be?
Suddenly a light bulb came on! The bulb! Could it be as simple as a bulb? I swapped in the bulb from the working other light and yes, it was a burned out bulb. Problem solved. I looked up the bulb number and soon the nav lights were functional! OK, not both strobes but I decided that could wait. I put the wing tip assembly back together on the left wing and declared light problems were fixed for now.
So a quick thing about what my 1946 Ercoupe needs to be legal to fly at night. Notice I said “legal”. Not ideal. Since at the time the plane was certified all that was required was navigation lights that is all the plane has to have. I have had many folks claim to say it needs strobe lights or a beacon of some sort but that just isn’t true. At least I can find no credible source that says otherwise. My plan down the road is to change the modified tip lights I have now to the stock Grimes units.
Which are still available and add some sort of “belly” strobe or beacon. Probably an LED unit. I am in no rush to do that as I mentioned I don’t expect to fly at night much.
One final note I’ll share is that while hooking up and disconnecting the battery debugging the lights I dropped the wing nut battery connectors into the bottom of the plane nearly loosing them about a dozen times!
So you would think that putting in the new air filter would be simple. Not a chance! Not with an Ercoupe anyways. I got the new filter element and in case I didn’t like it I decided to order the alternative Brackett kit. So I quickly learned the new original filter was a hard press fit into the Ercoupe air intake tube. No wonder the old one needed a slide hammer to remove! Also the more I learned the more I didn’t like it. I has a paper filter element that you are suppose to clean regularly and other Ercoupe owners said that they could come apart and be sucked up into the carburetor! Here is the original all taken apart and a new one for comparison.
And here is where the filter is supposed to go.
So the Brackett kit consists of two round screen pieces that hold a foam element in place The whole unit is held in with three small screws. That seemed a lot better. Every year you are supposed to replace the foam element. They are only $12 so a bargain! It turned out to be a little harder to fit the kit that I hoped. The old air tube had a buildup of paint and had become slightly out of round. So I had to spend some time with a dremel tool to do some clean up and grinding to make it all fit. The I had to find a way to get a drill in to drill the mounting holes in the air tube and then put it all together. It all took about half a day but it is now in and I think a superior solution. Here is the new Brackett filter in place. You can see the three clips that hold in the whole assembly. This clips are held in with three short machine screws. The kit was a bargain and I highly recommend it!
So modifying Woodstock to use this filter does require filing paperwork with the FAA. The required form is included int he kit and Stephen said he’d be happy to do that for me. 🙂 The form required is often called a 337.
Form FAA 337 – MAJOR REPAIR & ALTERATION (Airframe, Powerplant, Propeller, or Appliance)
Several would end up being filed for Woodstock during this process.
The next thing I needed to do was remove, clean and paint the battery box. While a new battery was put into Woodstock as part of the purchase it looked like at some point a battery had leaked. There was corrosion on the bottom of the battery box, There was now way I could see to clean it up while it was in the plane. So it had to come out. Again I owe my friend OIan a huge thanks for his help. The screws holding it in had been painted over and were in horrible shape> I was having trouble getting in there to get it out and he pitched in and got the screws out. So I cleaned up the bottom of the battery box with baking soda then wire brushed it. Once it was dried off I shot several coats of epoxy black paint on the inside of the box. I did the same thing to the inside of the top of the battery box. Additionally I added a layer of black electricians tape on the top of the box over the battery. I bought all new hardware to remounted the box, well Olan probably did more than I did. 🙂 Before putting the battery box back in I sprayed the area the box mounts to liberally with Corrosion X (ordered from ASS, Aircraft Spruce and I are becoming fast friends!)
This is supposed to be an excellent anti-corrosion product. It seems like a more persistent machine oil but folks say its good!
With that the battery box portion of the work I had to do was finished.
I still needed to replace the solid wire center of the trim able. The outer portion looked fine. But the inner had become corroded. I got the new wire and got some spray can light oil and sprayed a large amount of oil into the outer housing from both ends before putting in the new center wire. I had Olan continue to spay oil on the center wire while I inserted it. Now I had a nice new wire that moved easily in the outer housing. Also well lubricated one to prevent future corrosion! All I would have to do is reattach the ends and trim the excess length.
I did not finish the trim cable till a while later but I’ll share this part here. The end cable clamps were probably original. The one outside the plane was looking like replacing it would be a good idea. So I decided to replace both ends. Here are the old ones. It turns out only one company makes the FAA approved part for the Ercoupe. They stopped making them for a while! But then someone started making them again. All the new ones all are fitted with a castellated nut and a small cotter pin.
Time for an airplane owner moment. I ordered two new ones and learned they retail for nearly $100 ea!! I got them for the bargain discount price of $48 ea.
Now all that remained was to get Stephen back to reassemble the fuel pump. Put the prop back on. Replace the spark plugs. Inspect the trim cable and then I could finishing putting the plane back together. The all the remained was to fly fly fly!!
I was able to get him scheduled to come back. On April 19 he flew out in his very nice Navion and finished the last of the work he had to do. We looked at the logs and he decided he’d take them with him, review them and verify all my AD were complied with. He took the paperwork for the Brackett air filter and said he’d get the completed logs sent back to me but the plane was legal to fly once I had it back together! Woot! So total cost of the annual after paying him and all the stuff I needed to order was well under $800.
So I finished up a few things quickly, again thanks Olan! The wing inspection port covers went back on quickly. I used a little contact cement on the base rings in the cases where they were lose. The wing attachment fairings went on easily, I did replace one metal screw with one of a larger diameter in one case as the hole was too worn to allow it to be tightened. The tail fairing also was quick to replace.
Putting the cowling back on the plane was a bit of work and I replaced all the hardware. I can’t say I like how it fits back on but I don’t think it was any worse that it was before I took it off, I put in the new header tank float. A simple operation after lubing up the gasket with a special lubricant.
That only left on major task. I had decided I would fit shoulder harnesses and had purchased a kit from Alpha Aviation. There was enough work there to be the next installment and I’d like to cover it in its owner blog post as a reference for other Ercoupe owners that want to use that kit.
So that’s it for this installment. Next time we drill holes, cut ourselves, make sparks, learn new original swear words and move a step closer to flying!