Flying Again
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- Written by Kevin Horton
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The PMag installation took quite a bit longer than I hoped, largely due to poor access to some of the areas I was working in. It was a real pain running the wires to the aft end of the switch console in the cockpit so I could have the CB in a logical location. Access was poor to the mag area on the back of the engine - there were many times when I could only get one hand on a task when it would have been 10 times faster if I could have used both hands.
I finished the installation late Saturday afternoon. I had hoped to do an engine run on Saturday, but I was pretty beat by the time I finished, and I knew that I should do a good final inspection first, and I was too exhausted to do a proper job. Sunday morning I did the inspection, then a short engine run to check the ignition system. The ignition worked well, but the rpm indication on the engine monitor was screwed up - it was reading zero at low rpm, and twice the correct value at higher rpm. This was an easy fix - I changed the engine monitor number of pulses/revolution setting from 1 to 2, and the sensitivity from low to high.
I looked for oil leaks after the engine run, then installed the cowling and went flying. The ignition worked perfectly, but I noted quite a bit of oil on the bottom of the aircraft after landing. I pulled the cowling again, but there was so much oil on the back of the engine that couldn’t nail down where it was coming from. The area around the PMag seemed dry, so I don’t think it was the source. I checked torque on all the bolts, nuts and hoses on the back of the engine, but didn’t find any obvious loose items. I was able to turn three oil hose connections slightly, but I don’t think either of them was loose enough to cause such a large leak.
I also need to redo the manifold pressure plumbing for the PMag. I couldn’t find one of the fittings I would have preferred to use, so I did a temporary jury-rig job. I think I have found a source for the needed fitting on Monday via another RV aircraft owner.
I’m searching for a UV light bulb, as apparently aviation oil shows up well in UV light. I’ll confirm the UV light shows the oil, then clean the engine, and confirm it is clean under UV light. Then I’ll do short engine run and check again.
Magneto Failure
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- Written by Kevin Horton
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It’s been a busy week. One week ago I had to cancel a flight to Carp, for the EAA Chapter 245 Fly-In Breakfast, due to a hangar door opening winch failure. We quickly determined that the reduction gear box had failed, but the gear box had no data plate or markings on it, so it was not possible to source a direct replacement. We found a larger gear box at Princess Auto, but it wouldn’t fit on the existing mount, so quite a bit of barnyard engineering was required to get it all working again. We (those with aircraft trapped in the hangar) had several work sessions over the course of the week, and finally got it all sorted out on Wednesday evening.
Terry and got up early yesterday morning, to fly to Green Bay, WI. But that plan fell apart at the engine run-up prior to take-off. Terry had noted that she thought the engine sounded a bit different than normal when we were taxiing, but I couldn’t hear anything strange. But, when I advanced the throttle for the run-up, I could tell that the engine didn’t sound right, and the amount of rpm achieved for a given throttle position was quite a bit lower than normal. When I selected the magneto OFF, the rpm increased by 300 rpm, which was very abnormal. This clearly indicated that the magneto timing was much too far advanced.
I left the mag off, and taxied back to the hangar. I removed the cowling and hooked up the mag timing box. I heard a momentary nasty noise from the back of the engine as I turned the prop to Top Dead Centre. That noise didn’t come back, but there was no indication that the mag points were opening and closing at all. We clearly weren’t going to Green Bay, so we unpacked and headed home.
Today I went out to the airport early to dig into the issue. I found that the mag base was broken, and the impulse coupling was very loose. There were signs that the impulse coupling had been hitting the base of the mag. The teeth on the magneto drive gear looked in perfect shape, and I couldn’t see any damage on the teeth on the drive gear in the accessory gear box.
I thought at first that some of the small mag case pieces were inside the engine, but looked around on the floor under the back end of the engine and found that all the missing pieces were accounted for. Whew!
The aircraft currently has one magneto and one Lightspeed Plasma II electronic ignition. The Lightspeed ignition works well, providing more ignition advance than the magneto at cruise power settings for increased efficiency, but it does require aircraft electrical power to function. The magneto will function even if the aircraft electrical system has completely failed, which is a huge plus.
I’ve been watching the developments at E-Mag for several years. They developed two closely related electronic ignition systems that fit in the magneto spot on the accessory case. The E-Mag, like the Lightspeed, required aircraft power. Its brother, the E-Mag model P (aka P-Mag) has an internal alternator, which generates power sufficient at 800 rpm to run the ignition. The P-Mag requires aircraft power to get the engine started, but after the engine is running it will function even if the aircraft electrical system fails, as long as the rpm is kept above 800 rpm. The first design P-Mags had some significant in-service problems, but they updated the design to address the problems, and the latest configuration (series 114) has proven itself in service.
I had decided to replace the mag with a P-Mag when the mag was due for its big inspection at 500 hours. Now that it has failed, I’ll do that change now. I’ve spent several hours planning the mod, making a list of all the things I should require, and I’ll order all the goodies Monday morning.
Wash and Wax Job
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- Written by Kevin Horton
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We finally had the right combination of weather and schedule this weekend to wash and wax the RV–8. We never got it done last year, so it hasn’t had this much TLC since 2012. We used the Mother’s California Gold three step process, as recommended by the painter who painted the airplane four years ago. Between the number of steps, the large area to clean and wax, and the intricate shapes to deal with, it takes Terry and I two full days to go the job right.
Saturday we got the plane washed, and the upper surfaces and sides cleaned and waxed. This is what it looked like at the end of the day on Saturday.
Sunday, we got the lower wing surfaces done, and Terry cleaned the canopy after we removed it from the aircraft. The inside of the canopy had quite a bit of residue from two static cling sunshades that we used last year - l left the sunshades in the canopy all summer two years ago, which was a huge mistake, as they left a lot of almost impossible to remove residue behind. It took Terry a lot of elbow grease and good quality 3M marine transparency cleaner/polish to get the canopy looking like new again.
The aircraft looks pretty strange without the canopy.
While Terry was working on the bottom of one of the wings, I removed the cowling to assess an issue with the exhaust pipe mount. The four tail pipes are secured as one unit by the exhaust mount, but the four of them are somewhat free to move laterally. I had noted signs that the large heat muff that surrounds the two right most pipes had been hitting the side of the exhaust exit tunnel.
At the moment the four tail pipes hang from two supports that bolt to the back of the oil sump. The supports locate the pipes vertically, but don’t restrain lateral movement. The only thing holding the pipes in one position laterally is the friction in the ball joints at the front of each tail pipe. The engine shakes around quite a bit during startup and shutdown, and I think this flailing would sometime be enough to overcome the friction in the ball joints and leave the pipes resting against the side of the exhaust exit tunnel.
I’ll add a third diagonal support which should hopefully keep them in their proper location.
Thanks Terry for all the help over the last two days!
Picton Fly Out
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Summer weather has finally arrived in the Ottawa area, and Saturday was pretty much perfect. Not a cloud in the sky, very light winds, and a high temperature of 28°C :)
The excellent weather was especially timely, as Saturday was the scheduled date for the second of the three planned group fly-outs from the Smiths Falls Flying Club. the first one, to Peterborough for lunch on 10 May, was a blowout, as the high winds scared most of the participants off. Terry and I missed that one, as I was on my to Europe on that day.
Saturday’s destination was Picton, ON, with a visit to the Waupoos Estates Winery. Picton Airport is one of the many airports built during WWII as part of the British Commonwealth Air Training Plan. These airports typically have three 2500 ft long runways in a triangular shape.
Manitowoc and Back
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We just got back late this afternoon from a trip to Manitowoc, WI in the RV–8 to visit some of Terry’s sisters. We flew down Saturday morning, via a Customs and fuel stop in Sault Ste. Marie, MI. 4.0 hours of flying time, and we landed at 11:30 AM.
On the way home, we took advantage of the unusually strong westerly winds, and came back non-stop, climbing up to 15,000 ft to cross Lake Michigan. 2.9 hours of flying time, with an average ground speed of 201 kt from take-off to landing, including two separate climbs to 15,000 ft and an instrument approach in Smiths Falls.
I had planned to cross the lake at 17,000 ft, but I should have climbed higher VFR before I picked up the IFR clearance. The 50 kt tailwind during the climb had us halfway across the lake before I got to 15,000 ft, and we were already within gliding distance of the eastern shoreline, so we started a slow descent to 9,000 ft. We had to climb back up to 15,000 ft approaching Toronto’s airspace, as their normal traffic patterns were disrupted with thunderstorms north of Toronto, and ATC couldn’t accommodate us at a lower altitude.
On the Road Again
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I was in Toulouse, France last week, via a stop over in London. I left Saturday morning, 10 May, and got back home late Friday afternoon. I was pretty jet-lagged on Saturday, but had got back on the step by Sunday afternoon, so I took advantage of the apparent good weather to get an RV–8 flight in. The weather upon arrival at the airport wasn’t quite as good as I had expected, with rain showers approaching, so the flight was pretty short. I landed just before the rain started, but didn’t quite manage to get the plane in the hangar before it got wet.
We had hoped to wash and wax the plane last weekend, but we didn’t trust the weather forecast enough to start that task. I really want to get that done before Oshkosh, at the end of July.