Here are some more notes from flight 3 - the first ones were done in a rush as I was getting ready to head to the airport for a road trip. Now I that finally have a few hours of quiet time this evening, I looked at the data I recorded on flight 3. I found some glitches with the scripts I wrote to record and analyze the data, so it has taken some time to decode it. The process should get faster as I fix the bugs in the scripts.

The aircraft performance appears to be fairly good, especially considering that the wheel pants and landing gear leg fairings are not installed. The rate of climb at 80 KIAS 1000 ft MSL at 30 deg C (density altitude of about 2950 ft) at 1620 lb weight was about 1730 ft/mn. The air was a bit bumpy right after take-off, so this is only an approximate value. This rate of climb is perhaps 120 ft/mn lower than that predicted by a hypothetical performance model I created. It will be interesting to see how the actual performance changes as the engine gets broken in, the excess oil gets sucked out of the air filter, and I put the gear leg fairings and wheel pants on. Maybe my hypothetical performance model is not too far off the mark.

At 4500 ft, 75% power gave about 165 kt TAS (calculated from the IAS value, so this assumes zero error in the airspeed system - that testing is yet to come). Builders generally report an increase of about 15 kt when the wheel pants and gear leg fairings are installed. And, the speed for a given percent power will increase with altitude. So, it looks promising that the aircraft should at least come close to Van's performance figure of 182 kt TAS at 75% power at 8000 ft. Also note that the mixture was full rich for these two conditions - the engine would make more power if the mixture was leaned a bit, and the speed would be a knot or two faster. I think the engine is quite rich at full rich, possibly because I put too much oil on the K&N air filter - I found quite a bit of red filter oil had been sucked into the air induction snorkel after the first flight.

While doing the one hour with power varying between 65% and 75% at 4500 ft, I decided to do one airspeed calibration test point. I did a four leg box pattern at 145 KIAS on the analog ASI, using the event marker to indicate the times of interest in the recorded data (if I am recording data, the trigger on the Infinity stick grip will send an event marker to the recorded data). I analyzed the data later, and really wasn't happy with the quality of two of the legs, as the speed varied more than I would want. But, I averaged the data on each leg, then put the averages into the NTPS spreadsheet - it calculated a TAS of 151.5 kt, with a standard deviation of 0.09 kt, which is extremely low. Maybe too low to be true, considering the apparent poor quality of some of the input data. If I take the TAS of 151.5 kt, and assume a reasonable ram temperature recovery factor on my OAT (the actual recovery factor will be determined on a future test flight), I calculate a CAS of 139.5 kt, which means the airspeed system appears to read about 5 kt too fast at 145 KIAS. This is only one data point, based on somewhat questionable data, so it will be interesting to see how the full set of airspeed calibration tests turn out.

I did two quick tests to see the rise in EGT at 65% power when leaning from full rich - I wanted to ensure that the engine was not running too lean at full rich. I found that the EGT would increase as below (EGTs are in deg C):

 FF      EGT1    EGT2    EGT3     EGT4
12.9      633     648     631      655  # full rich
  -        -       -       -        -
 9.3      752     766     748      777
 9.2      753     767     749      777
 9.1      761     775     755      782
 9.0      765     780     757      783
 8.9      765     780     757      783 # cylinder 3 peaks
 8.8      767     782     757      783
 8.7      770     787     752      783 # cylinder 4 peaks
 8.6      770     785     757      783
 8.5      770     786     757      783
 8.4      770     787     755      782 # cylinder 1 peaks
 8.3      770     787     754      781
 8.2      770     787     752      780 # cylinder 2 peaks
 8.1      770     787     752      779
 8.0      770     787     749      777
 7.9      769     786     746      775
 7.8      767     785     745      773

Note that each cylinder had a rise of between 126 to 139 deg C (227 to 250 deg F) which means that full rich mixture was very rich. The cylinders hit peak EGT in a range of 0.7 USG/h fuel flow, which is a bit more than desired for optimum lean of peak EGT operations. Down the road I may work with Airflow Performance to get some injector with different orifice sizes to try to tighten up that spread a bit. Also, when I review the data recorded from the engine monitor, it looks like I need to pull the mixture back a lot more slowly, pausing at each fuel flow to let the EGT values stabilize. I'll repeat this test at various power settings on a future flight.

I was supposed to fly a check ride in one of the Transport Canada aircraft yesterday afternoon, but it was broken. So, I took a half day of comp time, and went to Smiths Falls to fly the RV-8 instead.

First, I studied the upper cowling attachment to determine why I was having problems installing the long horizontal hinge pins that join it to the lower cowl. First, I put a tiny bit of BoeLube in the leading edge of each hinge eye on the lower cowl, and I put some on the hinge pin. Next, I took a good look at the way the hinge eyes stick past the edge of the upper cowl. I realized that my installation technique was not compatible with the design. I had been starting to align the hinge eyes at the front, and working aft. But, the way that Van says to install the hinge, doing it that way will lead to a condition where you need to give a hard rap of the hand to force the eyes past the edge of the lower cowl a few inches aft of the front. I managed to bend one of the hinge eyes by doing that. I carefully straightened the hinge eye, and from now on I will start the hinge eye alignment at the rear - it makes a big difference. The combination of these two things made a huge difference in the amount of effort to install the lower cowl.

For the flight, I concentrated on engine break-in, following the instructions in Lycoming Service Instruction SI-1427B. It is a long document, but in a nutshell it calls for one hour at 75% power, followed by one hour alternating between 75% and 65%, and then 30 minutes at the manufacturer’s maximum recommended power (whatever that is for an RV). I decided that the two previous flights had effectively been a total of a half hour at a bit more than 75% power, so yesterday I did a two hour flight - a half hour at 4500 ft and 2500 rpm and 24” MP (75% power), followed by an hour alternating between 75% and 2300 rpm and 23” MP (65% power), followed by 30 minutes at 2500 ft at 2700 rpm and full throttle. The engine seemed happy at all conditions, with the CHTs staying below 375 deg F, and the oil temperature hanging around 180 deg F, except at max power, when it got up to about 195 deg F. The OAT at 2500 ft was about 25 deg C (77 deg F).

While I was droning around, I tested the Microair 760 COM reception. It uses an Archer antenna, inside the left wing tip. It was able to clearly pick up ATIS from an airport 50 nm away. The reception was slighty weaker if the station was off the right wing tip, but it was still readable. I didn’t try any long range transmission yet. I also confirmed the NAVs on the GNS430 and Narco 122D were working. And, I spent some time becoming familiar with the pages and menus of the GNS430.

I discovered that my round dial Van’s MP gauge intermittently seems to have died. Hopefully it is just a loose connection. Fortunately I also have MP on the Grand Rapids EIS 4000, and it works well. The Dynon EFIS heading seemed to be reading strangely sometimes. I may need to do another compass calibration - the original one was done with the engine OFF to avoid low power running. After the engine is broken in I’ll do another one with the engine running.

Terry videotaped the first flight from the ground. Last night I edited it, and pushed it out to YouTube overnight. It took forever to show up, but here it is.

I'm quite amazed at the large number of congratulatory e-mails and web postings I have received. I wish I could respond to each individually, but I have no time. I'll be on the road for four weeks starting Wednesday, and I have a lot of stuff to do before I go. But, understand that I do appreciate everyone's good wishes.

I arrived at the hangar this morning at 0730, and got right at removing the prop. I couldn’t borrow the engine hoist I had used for this task in the past, so instead I supported the sling from one of the rafters in the hangar. Once the prop was off, I found that the 7355 V-belt was a very, very tight fit to get over the pulleys. I cheated and removed the flywheel, which allowed me to get the belt over both pulleys, and then I slipped the flywheel back in place.

I also secured a second belt over the crankshaft, using two Adel clamps to ensure that it could not touch the flywheel. This will allow me to replace a broken belt in the future without removing the prop, but I will almost certainly have to remove the alternator pivot bolt to allow enough alternator movement to get the belt over the pulley, as I won’t be able to remove the flywheel if I haven’t removed the prop.

I put a heat shield between the exhaust system and the throttle cable.

All that took until lunch time. After lunch I put the plenum chamber cover back on, then attacked the cowling. I put some UMHW rub strips on the areas where the cowling showed signs of rubbing on the plenum chamber screws or oil cooler mount.

I had a very tough time getting the cowl hinge pins in place. Somehow I had bent one of the hinge eyes, and it took a lot of work to get it properly straightened. I am going to have to focus some attention on this aspect of the cowling, as I can’t afford to spend over an hour each time I want to put the cowling back on.

I then flew a 25 minute flight, pretty much a carbon copy of the first flight. After landing I pulled the cowlings again, and confirmed that the alternator pulley had not touched it, and the throttle cable seemed no more damaged than before. I will order a new throttle cable, and replace it at the first convenient opportunity, to avoid the risk of a problem in the future.

I recorded data from the engine monitor, EFIS and GNS430 (I tried to do that on the first flight, but I screwed it up). I confirmed the data is good, but for some reason the program I wrote to automatically create plots of the data isn’t working. Something has changed since I last tested this program two years ago, and I need to spend some time figuring it out. I’ll look at this in my spare time when I am on the road over the next month.

Well, today didn't turn out as I had hoped.

I went to the hangar mid-day, to pull the cowlings and do a good inspection ahead of the firewall before going flying to do some more engine break-in. But, I discovered two significant issues that needed dealing with ASAP, and another issue that will need correcting eventually.

1. The alternator pulley had been touching the lower cowling, and put a pretty good gouge into it.

2. The throttle cable showed signs of heat stress where it passed close to the exhaust system. I had thought that there was enough clearance, but obviously not.

3. There were signs of a bit of rubbing on the upper cowl from part of the oil cooler mount. Also, four of the screw heads that hold the plenum chamber cover on showed signs of rubbing on the cowling - three of these were very minor rubs, but one was more significant.

When I first saw the gouge in the cowling from the alternator pulley I was pretty bummed out. But, I quickly recognized that I had expected there to be some issues that needed fixing, and moping around wasn't going to help me get them fixed. All the issues are resolvable - it will just take a bit of time and effort. Once I snapped out of my funk, I put together a plan of action, and started to implement it.

I did a lot of running around this afternoon, but eventually found two Gates 7355 alternator belts 7/8" shorter than the Gates 7365 I have, which will move the pulley 7/16" closer to the engine. It'll be a bit of a bear to get the shorter belt onto the pulleys, but I found one posting from a builder with the same alternator who said he was able to do it.

Tomorrow, I'll pull the prop and change the alternator belt. I'll put a piece of tape over the gouge in the cowl to act as a witness for future clearance issues. If I still have a clearance problem with the 7355 belt, I'll have to fabricate some sort of pad on an arm to prevent the lower cowl from being pushed closer to the engine by the ram air pressure. Once I am sure the clearance problem is resolved, I'll fill in the gouge.

I'll put a heat shield on the exhaust where the throttle cable passes by. That'll be a quick, easy fix.

As for the oil cooler mount, today I removed a bit of metal from the mount in the affected area. I'll put a piece of UHMW tape on the cowling, and see how it does. I can remove more metal if needed. As for the screws that touched, eventually I'll replace those four with flush head screws. For now, I'll remove those screws, as there should be enough other ones to hold the cover in place. I'll put some UHMW tape on the cowling to act as a rub guard. In the end, it may be necessary to rework the contours of the plenum chamber cover to move the outer edges closer to the engine. This would be a big job, so I am hoping to avoid it, if possible.

I'll do another 20 minute flight to see how things are doing. Maybe late tomorrow, or maybe some other day if the work takes too long.

Originally, I had planned to fly for an hour on the first flight, in order to minimize the low power running time. But, Ron MacEwen, the local Aircraft Maintenance Engineer and EAA Flight Advisor suggested that it would be better to only fly for 20 minutes or so, and then do a big firewall forward inspection before flying again. I am very glad I took his advice - I believe that the alternator pulley would have completely worn through the lower cowling if I had flown for an hour, which would have necessitated a lot of fibreglas work to fix. As it is, I only need to mix some resin and fibre to fill the gouge - that'll be a quick fix, and it can wait for a few flights.

Moral of the story - keep those first flights short, to minimize the risk of undetected small problems quickly becoming big problems. A lot can happen in the course of an hour.

Well, its been ten years, 10 months, and a few days. But at 1600 this afternoon RV-8 #80427 finally got airborne. I circled overhead CYSH at 2500 ft at high power for about 15 minutes, being sure to keep well within gliding distance, just in case. I then pulled up to 5000 ft to do a simulated approach and flare. Then I brought the power back up and pulled some g to descend on the north side, crossed over to a very tight downwind and final and landed. It wasn't the best landing I ever did (I had a small bounce), but it was the most satisfying.

The aircraft has no major snags. There is a bit of left wing heaviness, and the front cockpit heat seemed to be pumping out hot air even though the control was OFF. I'll pull the cowlings tomorrow to give a good look at everything ahead of the firewall, sort out the cockpit heat, then if everything is OK, and the weather is suitable, do another hour circling overhead doing engine break-in.

My Special C of A finally arrived, so the first flight will happen as soon as I am in town with free time and good weather. I'm on the road now, but hope to arrive home Thursday evening. I go back on the road again on Wednesday, September 3rd, and will be traveling continuously until October. I hope to get airborne in the window between this trip and the next one.

I had a very busy week - went to Toronto early Monday morning for two days of meetings. Tuesday night I flew to Brazil, arriving Wednesday morning, and went straight to Embraer for meetings. Thursday I did an ERJ175 autoland flight test, more meetings on Friday, then flew home Friday night, arriving Saturday morning. Tired. Very tired.

This afternoon I went to the hangar, and installed the forward and aft baggage compartment floors, the spinner and cowling. All I need to do before I fly is put some more fuel in the tanks. I have no idea when the paperwork will arrive. If it comes on Monday, maybe I’ll get the first flight off Monday evening. Otherwise I’ll be heading on the road again Tuesday morning, coming home late in the week.

This next week is going to be brutal. Early Monday morning I will head to Toronto for two days of meetings. Tuesday evening, I’ll catch an overnight flight to Brazil, arriving mid-day on Wednesday. I’ll head straight from the airport to Embraer’s factory, to have meetings. Thursday will be ERJ-175 autoland flight testing. More meetings on Friday, then an overnight flight back to Canada, arriving in Ottawa sometime Saturday morning. Ugh.