I had GG up doing 75% speed trails the other day and was feeling pretty satisfied with 181 knt (208 mph) TAS at 9,000 DA. I programed in four way points to make a box with about 8 mile legs and let the 55X do the driving. I monitored engine data and air speed data while taking notes. It was an 80+ day and my temps were good, so the whole endeavor was a pleasant confirmation of GG's abilities.
Upon completion of the speed boxes, I decided to fly over my place on the coast and make sure the fishing boat was still in the yard. This area is a blast to fly around in the Searey, but not a comfortable situation in a plane that can only make one, not so good, water landing. I buzzed the house at 1200' (the boat was still there) and the pulled a two G turn back towards A grass strip about 5 miles away.
You know how they say you always think the engine runs rougher over water? Well, all the sudden my engine was running rough when I began feeding her fuel again! The problem was this was not something that was debatable or a part of an active imagination, she was stumbling!
I fly my Searey into the 3,000' grass strip all the time when in this part of the world, but have avoided bringing in GG because it is a little bit rough and I have had visions of getting a big crack in my close fitting wheel pants. Wheel pants or not, were going into the grass strip and now -hopefully! She would run smooth at MP 12 and about 6.2 GPH, but wanted to stumble if pushed above that level. I didn't push her, and just brought her in for a uneventful landing at 39FD.
After checking the plane over and making sure there were no fluids leaking or no obvious problems, I sat there and thought about it. I reasoned it must be an ignition problem and most likely the electronic side with such a difference. I tested and found she would run at full power after passing through the stumble area. So, I headed home and downloaded the flight data files and analyzed it with EGview.
Normally the #3 EGT (gray) runs in step between #2 and #4, but it was obvious #3 was deviating higher during the times I was experiencing the stumbles. According to the data, #3 was the starting point. After removing the cowlings, I pulled the lower (Electronic) plug on #3.........Bingo!
I recently replaced the leads on the electronic system and apparently had the end of this spring connector looping back towards the lead skin. It took it about 6 hours of flight time to break through and short out the plug. Without the help of recorded flight data, It might have taken a while to figure this one out.
Upon completion of the speed boxes, I decided to fly over my place on the coast and make sure the fishing boat was still in the yard. This area is a blast to fly around in the Searey, but not a comfortable situation in a plane that can only make one, not so good, water landing. I buzzed the house at 1200' (the boat was still there) and the pulled a two G turn back towards A grass strip about 5 miles away.
You know how they say you always think the engine runs rougher over water? Well, all the sudden my engine was running rough when I began feeding her fuel again! The problem was this was not something that was debatable or a part of an active imagination, she was stumbling!
I fly my Searey into the 3,000' grass strip all the time when in this part of the world, but have avoided bringing in GG because it is a little bit rough and I have had visions of getting a big crack in my close fitting wheel pants. Wheel pants or not, were going into the grass strip and now -hopefully! She would run smooth at MP 12 and about 6.2 GPH, but wanted to stumble if pushed above that level. I didn't push her, and just brought her in for a uneventful landing at 39FD.
After checking the plane over and making sure there were no fluids leaking or no obvious problems, I sat there and thought about it. I reasoned it must be an ignition problem and most likely the electronic side with such a difference. I tested and found she would run at full power after passing through the stumble area. So, I headed home and downloaded the flight data files and analyzed it with EGview.
Normally the #3 EGT (gray) runs in step between #2 and #4, but it was obvious #3 was deviating higher during the times I was experiencing the stumbles. According to the data, #3 was the starting point. After removing the cowlings, I pulled the lower (Electronic) plug on #3.........Bingo!
I recently replaced the leads on the electronic system and apparently had the end of this spring connector looping back towards the lead skin. It took it about 6 hours of flight time to break through and short out the plug. Without the help of recorded flight data, It might have taken a while to figure this one out.
