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5 Sep 09

I confirmed that the engine will quit with "Both" selected on the fuel selector and one tank empty.  It will then restart and run if you select the tank with fuel remaining.  So, should one have a leak on one side and not notice it (not hard to do with the Princeton capacitance probes since they don't work), the fuel will feed until one tank goes dry and then the engine will draw air from that tank.  Switching to the full tank restores power.

After running the tank dry, I drained the remaining unusable fuel - it was two ounces.

7 Sep  09        Today - 0.9        Total - 7.7

Finally got my EFIS One back and installed.  I won't go through the hassle with Blue Mountain, but it was aggravating.

I looked at the throttle linkage in detail since I'd had a momentary jam last time I flew.  I could find nothing that stood out as the problem - as the mechanics say "CND."  The problem probably occurred due to interference between cockpit levers, but they all have clearance and function properly.

I decided to fly today and check out the EFIS and build some time.

The goals for the flight were:

    Compare Airspeed and Altitude indications

    Short Field TO

    Take an offset after TO

    Climb at 87 KIAS to pattern altitude

    Check the heavy wing issue again

    Get more familiar with the EFIS

    Run WOT above 5000' to check IAS

    Practice 80 Kt, idle power, 45 degree bank, 180 degree turn

    Expand top speed envelope to Vne

    RTB for Full Flap Landing relying on AOA for approach

I had a small bit of engine surging during taxi out, but after the engine runup and after landing, the engine ran smooth.  The engine runup is becoming second nature now so I was quickly ready for takeoff.  The takeoff was as expected - powerful acceleration, quick liftoff, and rapid climbout.  The main EFIS indications were checked early in the roll and they appeared to be correct.  Later the altitude was within 40' and the airspeeds were within 2 knots.  I believe the airspeed difference can be adjusted out in the software - and I believe the EFIS Lite is the more correct one.  I'll have another pitot-static check on Thursday to find out for sure.

By holding best rate speed (87) I was at pattern altitude in about 17-18 seconds.  I took one trip around the pattern for safety and then off to higher altitude to do some work.  The heavy wing is still ... heavy.  I need to come up with a solution for it.  I guess I'll try squeezing the left aileron trailing edge some more.

At 6000' MSL with WOT (about 23") and 2400 RPM I could only get 168 KIAS, so it looks like that may be the best I can do.  Next time I'll climb to 8000' and check for max indicated speed and ground speed.

I have a theory about returning to land after an engine failure on takeoff so I did some simulated engine failures with idle, 45 degree bank and 180 degrees of turn.  My idea was to hold best glide (80 KIAS) during the turn.  With getting used to the EFIS, the AOA and the airplane, it took me 6 tries before I could come close to my target numbers.  But, my actual numbers come very close to my theoretical numbers.  With bank 45, airspeed about 87, AOA on optimum, I could allow a 3 second reaction time and still make a 180 degree turn in 18 seconds losing 450' of altitude.  I'll continue to build on my theory, but it appears an engine failure at 500' AGL can result in a safe landing on the departure runway.

During RTB, I pushed the speed to 200 KIAS (actually 203) so the airframe is safe to Vne.

I flew initial to the left break on RW 05.  Initial was at 184 KIAS so a lot of speed had to be lost in the break.  Idle was required and I still had 100 Kts beginning the final turn despite a departure end break.  With full flaps it settled into a comfortable 72 Kt final with optimum AOA (74 on EFIS Lite), so the 75 KIAS approaches I've been using were about right.  Kind of a clunkly landing and I failed to hold the nose wheel off very well.  Also, I didn't notice that I hadn't quite reached idle throttle position during landing roll.  It had nothing to do with the previous jammed throttle - I just didn't bring the power all the way back.  The engine purred like a kitten during taxi back.

Engine numbers for the flight follow:

There's obviously something I don't understand, but it seems odd that the highest CHTs occur at the lowest OAT.

Number 3 is still running high on CHT.  Maybe some work on the injector will solve the problem.  The Oil temp is not an issue, so my toilet drain air supply for the oil cooler is dead on.

And I'm beginning to think the FF numbers are not right.  I cannot get below 13 GPH at 24 square and leaned at 6000' MSL.  That just cannot be right.  So, next flight:

    Top the tanks and compare actual fuel used to engine monitor calculated burn

    Check the VOR operation

    Check the ILS operation

    Do another TAS check

    Check the heavy wing again

    Try the autopilot in heading hold

While installing the EFIS One, I found the GPS coax connection to be damaged, so I need to remove the antenna, take it to the Deland avionics shop and get them to crimp on a new end.  Maybe I can do that this week.

10 Sep 09        Today 0.7        Total - 8.4

11 Sep 09

12 Sep 09        Today - 0.4        Total - 8.8

Started and taxied out several times today but couldn't get a good engine runup when I got to the runway each time.  Taxied back in each time, pulled the cowlings, cleaned the fouled plugs, and taxied back out for the same result.

While back at the hangar, I broke my self-imposed rule of not changing more than one thing at a time and decided to adjust the prop governor to get higher RPM.  I've only been getting 2550 RPM on takeoff and I should be getting 2700.  I wish I had focused on only one thing - the ignition - until I got it solved.

Finally got a good engine runup and took off intending to climb above 8000' and do some speed checks.  But. the airplane seemed a bit sluggish after takeoff so I decided to make several trips around the pattern.  After the third pattern I started to depart the pattern and heard and saw the engine drag down.  I could add throttle and keep speed okay, but it took more throttle than normal.  I landed immediately.  The EGTs went higher than normal after the engine bogged down.

So, back to the hangar for more study.

The prop governor adjustment did work and I'm getting 2640 on takeoff, so only a small adjustment now to get 2700.  Odd though, I didn't think about how the higher RPM would affect pattern airspeeds.  With the prop pitch so flat, the airplane really slows down quickly and I have to carry much higher throttle on final.

20 Sep 09        Today - 0.5        Total - 9.3

No recent flying due to a cold.  But, today I checked the P Mag timing and found the two mags to be timed slightly different.  So I decided to retime them and as I was about to remove the mags manifold pressure line, I found that it was already mostly disconnected.  That was probably what caused the engine to act up on the 12th.

I retimed the mags three times and each time I got a solid green LED on the left mag but a flickering one on the right.  I'll contact E Mag Air about it tomorrow.  Secured the MP line and decided to go flying around the pattern to see how it would run.

Engine Readings

First numbers are at Takeoff

21 Sep 09        Today - 0.9        Total - 10.2

I talked to the E Mag guys and the mags are set okay.  They said my mags are more accurately set than standard mags could have ever been set.

I have a theory, supported by the E Mag guys, that the engine mixture is set far too rich.  The lower plugs are fouling too rapidly, the fuel flow is much higher than it should be, the EGTs are too low, and the engine will not quit running when the mixture is pulled to cutoff during engine shutdown.  So, today I decided to lean at all times except takeoff even though the flight was to be only at low altitude.  I'm just getting over a cold so I didn't want to climb to higher altitude because of the ear discomfort during descent.  Leaning proved to be a good thing and provided good data.  I also reread a Lycoming article about running high power during breakin to seat the rings and avoid cylinder glazing.

So, today's flight was at high power with primary focus on engine indications.  I had a caution warning today (that I've had several times in the past), but the red font on the AF-3400 is so tiny that, with a bit of turbulance, it can't be read in the cockpit without a magnifying glass.  It turns out the warning was AMPS, so I think it was detecting a low amp reading on the aft battery (actually reverse flow through the shunt) and gave me occasional "warnings," which is bothersome in flight.  I'll adjust it to stop that annoyance.

I noted on this flight, as well as the last one, that my bus voltage drops significantly as I increase amperage load on the bus.  Discussions with the internet electrical experts indicates that my fat wire from the alternator B lead to the battery isn't fat enough.  The best voltage I get at the bus is 13.6v with most everything turned off and it drops to 13.2v with a 32 amp full load (except pitot heat).  So, I may have to change the wire to a heavier gauge.  That's for later.

Engine Readings for Today

Today's flight was at 1000' and 25-2600 RPM with 25-26.5" MP and "leaned" to about normal mixture setting.  The fuel flow was down significantly from 19 GPH earlier.  The Oil Pressure and Temp are holding steady in good ranges.  The EGTs were a little higher - which actually look better than the cooler temps before.  And the CHTs are right where they've always been - with #3 still the highest, although well within limits.  The max CHT for the engine is 450.

So, I obviously need to adjust the mixture - now I have to figure out how to do it.

22 Sep 09

The problem with the plug fouling is definitely the excessively rich mixture.  After leaning during yesterday's flight, I pulled the plugs today and they were clean and dry.  I decided to swap the plug top to bottom and as I was cleaning and regapping (.035) them I noticed in the E Mag Air manual that the auto plugs with adapters aren't supposed to be used on engines which require the long reach (13/16") aircraft plugs.  I called Allan Barrett and sure enough, the IO-390 requires the long reach plugs (as indicated by the yellow paint on the cylinder tops).  So, I've been flying with auto plugs when I shouldn't have.  But, the E Mag guys said others have been flying with the auto plugs when the engine is supposed to have the long reach plugs.  And mine's been running okay.  And it will take two day's work to reconvert to the aircraft plugs.  And I have to order new wires.  So, for now, I'm going to keep flying the auto plugs.  I'll order the wiring and begin the conversion next month.

Adjusting the mixture is not as easy as I thought.  I assumed it would be a simple adjustment on the injector body.  Actually I have to order a new fuel jet from Airflow Performance.  But, I'm not sure what size I have or what to order.  I need to get them on the phone.  For now I'll lean everywhere except on takeoff and go arounds.

I may need to adjust the idle mixture also, but that can be done by twisting screws and connections.

I modified the #3 cylinder air dam and left the air deflector in place.  I'm anxious to fly it again and see how the #3 CHT does.  If the CHT drops, then I'll try removing the air deflector and check temps again.

I also made another small adjustment to the prop governor which should give me 2700 RPM on takeoff.

Then I closed up some more holes in the baffle with red RTV.  Eventually I'll get the plenum and baffle nice and tight and then I can start working on reducing the size of the cooling air intakes.

I was looking at the EAA experimenter web site and there is a guy (Paul Lipps) who has some unique ideas about cooling air flow.  He's working with a composite airframe, but his concepts could be applied to a RV.

I still need to hop over to Deland and get my GPS antenna coax repaired.  Maybe tomorrow.

23 Sep 09        Today - 0.8        Total - 11.0

I was anxious to see the #3 CHT readings again - don't know why - they didn't change appreciably.  Got in a flight today all at 1000' and about 25 square.  I leaned all but takeoff and landings.

The takeoff was short and quick and I climbed at 87 to pattern altitude.  I stayed close to home as I watched engine readings and then left for a while before returning to the pattern for 2 T&Gs and a full stop.  I am not happy with the airspeed and altitude indications.  They are different and vary by different amounts at different altitudes and airspeeds.  I just am not happy with the indications I'm seeing.  At 1500' I was indicating 150 KIAS and ground speed was 180.  A 180 degree turn and 150 KIAS gave a GS of 176.  The winds were basically calm.  At that altitude the TAS should only be about 154 and, no wind, the GS should be about the same.  It seems to me the AS indications are wrong.  At slow speed they seem to be reasonably close, but I still do not have confidence in them.  The AOA is helping a lot in the pattern.  So, I really need to fly with another airplane to check all indications.

Engine Readings follow:

I called Airflow Performance today and left a message and they called back after I'd flown.  I felt sure the main jet in the fuel injector was too large because the FF was too high.  But, they said if it's too large, it's only a tiny bit too large.  He asked my fuel flow on takeoff and induction type.  Fortunately I had the detailed numbers from the engine monitor and told him Bowers ram air and a FF between 20.3 and 21 GPH on TO.  He seems to think the FF numbers are about right - or maybe slightly rich.  I suppose he has standard charts based on BSFR (about .50 for the IO-390) that tell him what it should be.  Anyway, he was very helpful and gave me some tests to try before we make a decision to change the main jet.

He said to check the idle mixture by:

Rpm 1800 to clear out engine

RPM 750 (idle)

Lean rapidly to half and then slowly lean

If there is a Manifold Pressure drop, then it's too rich

If there is no drop in MP, then it's about right.

And next time I fly, he said climb to 3000' and:

RPM 2400

MP 23"

Lean to peak and record the EGT and cylinder

Push the mixture back to full rich and record the EGT on that same cylinder.

If the difference is 200 to 225 degrees, then it is okay.

Additionally:

He said to shutdown the engine using the purge valve.  I told him the engine would not shutdown using the mixture cutoff and he said it's better to use the purge valve to shutdown because the mixture cutoff doesn't stop all fuel whereas the purge valve does.

So, I'll plan to do those tests tomorrow and update my checklist.  I'll fly to Deland tomorrow and get the GPS coax repaired and do the tests during those flights.

24 Sep 09        Today - 1.0        Total - 12.0

What a difference a day makes.  I flew to Deland to get the GPS antenna repaired.  Before departing I did the idle mixture check and found the MP dropped from 13.8 to 12.5 as I leaned.  Apparently that indicates the main jet is too rich.

On TO at 7FL6, I tried a technique I've used for years to get little planes airborne at the lowest possible speed.  It works best with manual flaps and has saved my bacon more than once.  With manual flaps, I rapidly pull in full flaps about 5 KIAS/MPH before normal liftoff.  The airplane will elevate vertically and then you bring the flaps up slowly as the airplane accelerates in ground effect.  On a soft field or grass strip with tall grass it get you up out of the stuff that is hindering your acceleration and you can accel in ground effect.  So, I tried it today with my electric flaps.  Since I have the Show Planes flap setting device, it requires 3 activations during TO roll.  I started the flaps down as I hit full power and the plane flew off very smoothly.  I like the technique even with electric flaps.  Good climb rate to pattern altitude and off to Deland.  The tech there was very helpful and discovered that the GPS antenna problem was not with the antenna wire but with the EFIS connector.  BMA should have repaired that while they had it in TN.  Anyway, we got it repaired and as I was removing and reinstalling the EFIS, I noticed the pitot tube was cracked at the fitting into the EFIS.  No wonder the airspeed indications haven't made sense!!  The pitot lines were leaking!!  We cut off the cracked portion, added on some higher quality tubing and tie wrapped them.  Airspeed on the way back indicated as it had a week ago.  I guess the cracked tubing was causing low airspeed indications.  My confidence in the airspeed indications is regained.  I got readings from the EFIS of 173 KIAS, 181 TAS and 162 GS at 2000' MSL.  At 1200" I had 171 Kts, 180 TAS and 165 GS.  Those make sense to me.  Also, the GPS now works as advertised.  So, several important improvements during that short trip.

On the return trip I climbed to 3100', set the power to 2400 and 23" and leaned to peak.  The #2 cylinder peaked first at 1433 with a FF of about 10.5 GPH.  IAS was 150-155, so pretty good numbers.  Then I went to full rich and the #2 EGT read 1155.  That is a difference of 278 degrees which is outside the acceptable range as described by the Airflow guys.

So, I called them back and during my conversation with Don at Airflow Performance we decided that it's too rich and to switch the main jet from a 49.0 to a 49.5.  That should arrive next week.  He also thinks the idle mixture needs to be adjusted very slightly by "one flat," so I'll do that at the same time I install the new jet.

The engine ran much smoother today when it was properly leaned.  It was obviously running far too rich.  And I got good numbers for leaning to LOP for use later.  And I discovered how the engine monitor peak detection works.  So, all good things.

Engine readings

1000' MSL

Readings before leaning to LOP - 3100' MSL

First EGT Peak was on cylinder #2

Here is the 50 LOP on #2.  All cylinders reached their individual peak before #2 reached 50 LOP

Then I went to full rich and got these readings

Back at 1000' MSL and partial leaning

25 Sep 09        Today - 0.5        Total - 12.5

Stayed in the pattern for five landings and one low approach.  Using 1/2 flaps when solo works very nice and 8.5 to 9.5 MP is perfect around the final turn.  82 KIAS in the run works nice and is just slightly fast on the AOA.  75 KIAS is good on final (AOA has two orange LEDs) and 72 KIAS over the threshold.  Touch and goes are a no brainer - flip the flaps up and add power.  It's easy to not bring the power all the way to idle during full stop landing which causes the landing roll to be too long and causes more brake use than should be needed.  I'm still getting a little nose wheel shimmy during landing roll, so I may have to tighten up the nose wheel breakout force again.

I topped the tanks before flying and the engine monitor said I had burned 32.5 Gal since the last fillup, but I only pumped in 29.5, so there is a slight difference between actual and the measurement.  I'll check it several more times before trying to make any adjustments.

26 Sep 09        Today - 1.2        Total - 13.7

The plan was to check out the transponder with ATC, learn more about using the EFIS by tuning and getting a radial on a VOR, check for a LOC signal, expand the altitude envelope to 10K' to check engine operation, lean to see how the engine operates, monitor CHTs, do 3 landings.

Good RPM now at max prop setting.  RPM hits about 2670 on TO, so one more tweak of the governor and I'll have it at 2700 RPM.  I'm going to remove the air deflector in the plenum and see what happens with the #3 CHT.  I had to watch the #3 CHT during climb to avoid getting too hot.  Still I was able to climb at 800 FPM at 9000' and 145 KIAS.

I climbed to 9800' and got a transponder check with DAB approach during the climb.  I tried tuning the VOR and ILS but couldn't figure out how to set the OBS on the EFIS.  Shouldn't be too hard to set the OBS, but so far I'm not getting it.  Same with the EFIS day/night selection.  Somehow I managed to set the EFIS to night mode and it's tough to see in the daylight.  I'll have to figure out how to switch back.  There's a lot to learn about the EFIS operation.

The CHTs dropped with proper leaning at altitude, but were too hot with a richer setting.  The CHTs settled into consistent readings once leaned and cruising at 9500' MSL.

During RTB, with 3-500 FPM descent it was indicating 185-190 all the way back.  Overall performance is coming along very nicely.  Three landings with 1/2 flaps.  The half flap setting is just about perfect solo.

Engine Readings from today

After TO at 1000'

Easy Climb at about 7500'

7500' Level

9500' and increasing CHT

9500' Leaned to 10.5 GPH - all CHTs dropped

Back at 1000'