·:[ Darryl's Coot Building Journal ]:·
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After building new side baffles, front baffles, and rear baffles, the next step was to reinstall the whole thing.

First, here are a few “before” pictures. I took these in July 2007, while evaluating the airplane for purchase. No doubt they were in even rattier shape after an additional 225 hours of operations.

In this photo, notice the multiple patches on the side baffles. Pretty ratty, huh? When I bought the plane, one of my first thoughts was that I needed to build new baffling.

Here is the other side. Notice the beads RTV…

The horizontal bead of RTV was, in fact, the only thing that kept those two pieces of metal connected!

Check out the crack on this front baffle. Also, notice the ugly (dry, cracking) rubber seal along the cylinder.

Most of the top seals were in excellent shape. Not so for those front seals.

Okay…back to the future. The Yankee was in Dave Wheeler’s shop in Arlington getting a cylinder overhauled during the plane’s annual. Dave kindly permitted me to do the re-baffling re-installation myself.

Here is the preliminary installation (notice that one cylinder is missing in these photos):

And here are some photos after the final installation (and after the first test-flight):

Happiness!

Okay…I finished these things months ago, but have not finished writing them up. We previously examined the Yankee re-baffling project with new side baffles and new front baffles.

The two-piece rear baffle was in pretty good shape. Mostly, the cylinder shrouds had been rendered to almost toothless combs:

Following disassembly, cardboard patterns were carefully constructed for each piece:

As with the previous pieces, new blanks were cut from 0.032″ 6061-T6 sheet aluminum.

Here is one piece after putting in the bends. Notice the cylinder shrouds are longer than in the original, that was intentional. I curled the cylinder shrouds over forms made of wood, after hammerforming in the bead:

The other piece was slightly more complex because of multiple bends, requiring more planning in the order in which the bends were made.

The next step was to reassemble everything for riveting:

and actually riveting and reassembling the whole thing together:

The next step…re-install the fresh baffling.

This evening I’m going over Lycoming Service Instruction 1427B in anticipation of breaking in my Lycoming 0235 in the Yankee tomorrow, following the reconditioning of one cylinder. The document describes the engine break-in procedure in great detail, including ground testing the engine with a test club in place of the prop. On page 3 comes the warning:

WARNING: ENGINE TEST CLUBS MUST BE REPLACED WITH APPROVED FLIGHT PROPELLERS BEFORE FLYING AIRCRAFT.

Umm…right. Got it.

As suggested in the previous post, I did end up building new front and rear baffles for my Yankee. Here is the journey for the front baffles.

First, take a look at these dogs:

The first thing to notice is that the rubberized seals are in abominable shape. They are hard and crumbly. But there is more. Notice the big patch on the lower part of the left baffle. At the top of that baffle there is a big ol’ crack (click on the image and it becomes clear). See that bracket on the upper part of the right baffle? that bracket is just about cracked all the way through. Finally, the original steel staples used to hold in the seals have eaten away at the aluminum they contact. Yuck.

Here is the view from the back side:

The crack in the (now right) baffle is plainly visible. The upper seals are clearly very worn.

The first task was to make cardboard patterns from the baffles and cut out new blanks from 0.032″ 6061-T6 sheet aluminum:

The air duct tube on the passenger-side baffle is rolled into the original baffle. Therefore, I simply cut the original out and reused it in the new baffle:

New cylinder baffles were cut and shaped to closely correspond to the original. These were made longer than the original. Upon final fitting, a 45 degree bend will be put in the ends and the front and rear pieces will be safetied together:

And, of course, a new bracket was bent from 0.04″ stock (7075 T6 in this case):

A few bends later:

The next step was to cut out new seal material. I used a product called Cowl Saver™ from McFarlane Aviation:

I used Avex blind rivets with a sandwich of AN-960-6 washers on the aluminum side and AN-960-6L washers on the seal side for holding the seals on. Cherry rivets were used for holding metal parts together:

The next installment will be the rear baffles, followed by photos of the installation.

My Yankee is undergoing its annual, so that seemed like a good time for a new set of owner-made baffles for the plane’s Lycoming O-235 engine.

The two side baffles were in absolutely hideous shape. Take a look:

The rubberized seals are in good shape, but the aluminum is in really, really bad shape. take a look at the other side.

Patch after patch can be seen. See that little chunk below the red silicon stuff? That is, essentially, held together just by that bead.

The factory stock baffling is made from 0.032″ 5052-H34 sheet aluminum. This alloy’s biggest advantage seems to be its low cost. A better (and slightly more expensive) grade for engine baffles is 6061-T6. (This is what AA1/5 guru Ken Blackman uses for building new baffles.)

I had enough 0.032″ 2024-T3 in stock, but that grade, while stronger, is more brittle. The 6061-T6 is recommended over 2024-T3 by folks like (the late) Tony Bengalis for building engine baffling. I ordered a sheet from onlinemetals.com, which happens to be about 20 minutes from my place of employment in Seattle. I picked up the order several hours later.

The first thing was to drill out the rivets for the rubberized seal, and then make patterns out of heavy card stock:

Next, I used rubber cement to paste the pattern on the sheet of aluminum, and did all the center-punching for the holes, and drilled the strain relief holes for some of the bends. Being a cheapskate, I optimized the layout to save aluminum and used a jig saw to separate the two sides:

Next, I cut the basic shape on a band saw (and a bit on the jig saw when I ran out of throat on the band saw). After carefully dressing the entire circumference of each part, I drilled and debured the holes.

Each piece had two 90 degree bends with a generous 1/4″ bend radius. I formed a die on a belt sander from 1/4″ bar stock. I have a lousy 48″ sheet metal brake that could have been pressed into service (and I could have used my monster brake), but it was easier to use clamps on the edge of the bench and a block of wood with a mallet.

Here are the final pieces:

The next task is to rivet the rubber seals back onto the baffles. Here they are all Clecoed up and ready for some pop rivets:

Total construction time: About 6 hours, including to time to make the (reusable) patterns. I have another hour to go for the riveting.

I learned this afternoon that one of my cylinders has low compression and needs to be pulled. Since the rear baffle will have to be removed to pull the cylinder, I may just build a new rear baffle. Stay tuned.

Update: For connecting the seal to the baffle, I used Cherry Rivets (MSP-42) with AN-960-6L washers on the rubber and AN-960-6 on the aluminum side. The final products:

What did I do this past weekend? Here I am with Russ Milham, who was in the left seat flying my Yankee. He did a couple of touch and gos and then landed the third time. We then joined an American Yankee Association fly-in at the Spruce Goose Cafe.

Fellow Coot-builder, Doug, has posted this wonderful video of the late Peter Breinig building a Spencer AirCar in five minutes.

In the opening scene, Peter is looking through Private Pilot and finds an article titled, “Build Your Own Airplane.” But the airplane shown is not a homebuilt airplane at all. It is a 1971 American Aviation AA-1A (built a year after my AA-1 Yankee). On the other hand, the AA-1 series was developed by Jim Bede, and was originally to be a kit plane.

This is part III of a series on N5814L, a 1972 AA-5 Traveler. Two weekends ago, we prepared the plane for trailering from Dave Wheeler’s Northwest Aviation at AWO to co-owner Russ Milham’s shop just north of Seattle.

Our adventures in trailering began with trying to find a suitable trailer. I posted a query on a regional aviation forum. A person named dww generously offered us his trailer, although it required a weekday pick-up an a bit of work to make roadworthy. The weekday pick-up proved to be difficult, because I don’t have a vehicle with a trailer hitch, and Russ’ vehicle wasn’t available during the week. But I also found a trailer for rent via Craigslist that was two minutes away from the airport.

Our trailering plans got put on hold for a week owning to an insurance snafu. Schedules didn’t allow us to get started until Saturday, mid-afternoon. When Russ showed up to pick up the Craigslist trailer, it was smaller than described and probably wasn’t going to work very well. Uh-oh. On top of that, the guy wasn’t willing to wait for Russ to do some measurements on the airplane and come back. Russ walked away.

I called an old friend, Richard V., who lives in nearby Marysville. Richard is a homebuilder with lots of connections in the local aviation community. His response? “I have a tilt bed trailer right here you can use. Come on over.” Wow!

After a few minutes rigging up an adaptor cable for the lights, we were on our way.

The Traveler is 8′3″ wide between the main gear tire midlines. We stopped by a lumber store and got a 2×8 cut to 8′6″, the maximum width allowed for a normal width trailer. With a little scrap lumber from a nearby dumpster, we rigged up a ramp.

(Another view.)

A couple of come-alongs were used to winch the plane into the trailer. The nylon strap from one winch was passed through the spar tube.

(Another view.)

The next step was to strap down the tail. Notice the 2×8 with a furniture pad underneath on top of the tail attach point. There is plenty of bendable aluminum in this area:

(Another view.)

…and lowering the bed of the trailer.

(Another view.)

The winches were replaced by cargo straps through and around the spar. A second strap was added to the tail, and engine components were secured with tie-wraps and covered in plastic and duct tape.

Finally, the wings were stacked under the fuselage with furniture pads in between. And the horizontal tail section was stacked on top of the wings.

(Other views: here, here, here, here, here.)

The road trip was uneventful. On our 30 mile trek down the I-5 corridor, we were passed by three police cars who, apparently, didn’t find it the least bit suspicious to be trailering an airplane under the cloak of darkness.

Unloading the plane was relatively simple using a thick piece of plywood as a ramp.

(Another view.)

The Eagle has landed.

The next stop was my house, where Russ dropped off the left wing and trailer. The day was a success, if a little on the long side—we end at about 1:00 a.m. Sunday. But quite a haul!

It was Saturday morning, 14 March 2009, and Russ Milham, a bunch of friends and I showed up at Northwest Aviation at AWO to dismantle N5814L, a 1972 Traveler, for trailering.

All of the photos in this post were taken by Steve Johnson, who also did a lot of disassembly work.

Here she is as we left her after inspection:

Here’s Russ surveilling the task ahead of us. Notice that cylinder one and its piston have been removed—that was from an inspection. We’re rebuilding the engine, so the rod was secured in a bed of cardboard for transportation.

And here I am bagging the lose stuff in the cabin.

The vertical fin is removed. You can see a person under the inboard end of each wing dealing with fuel lines and electrical connections in preparation for wing removal.

Following the service manual instructions was mostly helpful…as was the occasional swig of coffee.

My friend Tim Lange pulled the carburetor and alternator. The carb was sent out to a rebuilder the following Monday.

The last step was pulling the wings off, a process that required five people. One person was in the cabin to deal with the exiting torque tubes, two people were stationed at the outboard end and two at the inboard end. The idea was to engage in a coordinated rotation of the wing, with a bit of up-down rock to find the sweet spot where friction is minimized between the center-section spar and the wing spar.

We first tried the left wing. It was stubborn, but with persistent rocking the root eventually started pulling away from the plane 0.1 mm at a time. The first inch required about 90% of the effort. After that it was pretty simple. The right wing came off with no difficulties.

Steve was helping to pull the wing, so there are no photos of the process. Here’s the aftermath, with Russ and me tucking 14L into a corner.

All put away and awaiting a trailer….

We loaded everything but the horizontal tail section, the two wings, and the hull into our cars, and headed off into the sunset. Next post: Trailering a Traveler.

A couple of months ago, my Coot-building buddy, Russ Milham, and I were visiting Dave Wheeler and Northwest Aviation at their new location at the Arlington Municipal Airport (AWO). In one corner of the shop, we spotted some type of Grumman four seater.

We looked over the plane, an early AA5 Traveler, as Dave Wheeler explained that his shop was assessing the plane’s value for an estate. As it happens, Russ and I had been talking about a partnership in a 4-seater of some type. The AA5 family was definitely on our list. We took a closer look:

Don’t get me wrong…I love my Yankee, and it satisfies my mission about 80% of the time (solo local, solo cross-country, two-people locally). But the Yankee’s limited endurance with a passenger, limits on passenger weight, and limits on passenger height (to about 6′2″), sometimes gets in the way.

Anyway, Russ and I made a deal with Dave…we would do much of the labor required to inspect and assess the plane. That would give us a chance to do our private valuation, and the estate would get a less-expensive valuation. If we liked what we found, we would make an offer. Oh…I should mention that Russ is an A&P mechanic.

N5814L is a 1972 AA-5 Traveler, serial number 14. Based on on-board paperwork and logbooks, the plane has not flown since sometime around 2001. The interior is…well, old:

The panel is pretty basic and very dated. We didn’t evaluate any of the avionics, except to note that the ELT was missing.

Russ and I spend a couple of weekends opening up the plane and performing inspections. Our squawk list was long. There was a potentially un-reparable left aileron. Both fuel tanks leaked, a problem that requires an enormous amount of labor to repair. Shops charge may thousands of dollars per wing for resealing these tanks.

The engine needs an overhaul. It had had a field overhaul in 1994, but we had no paperwork whatsoever, aside from an insufficient log entry—no yellow tags for components or record of dimensional inspections. Either way, the engine has been sitting for eight years and is past Lycoming’s TBO of 12 years.

We made an offer to the estate. Dave Wheeler had assessed a similar value, and everything got passed onto the to estate. For several reasons, it took about five weeks for the estate to accept our offer and ensure a trouble-free transfer of ownership.

Last Saturday Russ and I bought the plane. We will do much of the work to return 14L to service ourselves. For starters, Russ is rebuilding the engine, and I am going to work on resealing the fuel tanks. (Of course, we’ll be shipping engine components out for proper measurement, inspection, and rebuild.) Most of the plane goes to Russ’ shop, whereas I get one wing at a time, and sort some of the components in mine.

Next installment…dismantling for trailering the plane.