Flight testing

First flight, 4/22/07, 0.8hrs : Over KHEF with the assistance of the tower.  Cleared to 2,400ft in between class D and B airspace, but did not get there.  On climbout at 95KIAS, CHT rose to around 435 degrees for #3 and 4 cylinders.  I throttled back at 1,700ft to around 2,100rpm (prop full fwd) and things cooled down right away.  Oil temperature, however, kept on climbing.  By the time I had gone around twice and landed, oil temp was up to around 235 degrees.  Apart from those two issues, the airplane flies very nicely, no tendency to roll, pitch, or yaw.  Soundproofind and interior paneling made it very acceptably quiet.  Knowing ahead of time that I would be too excited to take notes, I tried recording the audio through the passenger plug, but the recorder picked up too much ambient noise to be able to make out what I was saying.  Time to use the data logging feature of the GRT EFIS.

Measured the temps on the outside of lower cowling after the flight.  The spot under the left exhaust coupling was around 150 degrees, while the corresponding area on the other side was 120.  I'll have to monitor this to see if the fiberglass suffers from the slightly higher heat.

Second flight, 4/25/07, 2.2hrs: HEF-W66-CJR-dir OMH-OKV (2 landings)-HEF.  Takeoff climb at 110kts, rpm did not exceed redline at full throttle (Vans propeller evaluation, p15-19), CHT/oil temp within norms, at 1,700ft went to 24/24.  Out to W66, CJR, towards OMH at 24/24.  At 23.8hg/2,390rpm, #3CHT was 381degrees, oil temp 188degrees, 140KIAS.  Climbed at 1,000fpm at 24/24 over CSN to 3,500, #3CHT only went up to 394degrees.  16 minutes into the flight at 4,500ft, leaned the mixture a bit, 152KTAS, 138KIAS, getting 1,225degrees for #2, oil temp seemed to rise as a result of leaning (?) to 208degrees and #3CHT was 388degrees.  Enriched a little and oil temp dropped to 205degrees, #3CHT to 380degrees.  43 minutes into the flight at 24/24, oil temp was 200degrees and #3CHT was 371degrees.  In the pattern at OKV, prop fwd (2,360rpm), 13hg, 85kts.  Had to go to 10hg to slow down for full flap extension, then back to 15hg in order to stay at 75KIAS.  Both landings were too fast, with bounces/ballooning.  Got a low oil pressure alert during taxi when it reached 70psi.  Used the AP a lot, with success.

Findings: gotta figure out how to make the AP track the GPS flight plan.  Otherwise, AP worked perfectly.  Traffic alert seems to work fine, but it's hard to read on the 430 moving map screen and the traffic screen doesn't give any map information.  Need to get the pattern system down better, as dumping 40degrees of flaps is too much.  Rod Linde suggests 100~110KIAS downwind, 20degrees of flaps and prop in (prop is at stops when throttle controls RPM) on base, 30degrees of flaps on final max.  Oil temps and CHT were high around the pattern, so I only landed twice and then did another 24/24 run.

Third flight, 4/30/07, 1.5hrs: Phase I area.  Purpose of the flight was just simple 24/24 running in.  All went well, with a high CHT of 429degrees during climbout, but around 380 during cruise.  High of 201degrees on the oil temp was outstanding news, especially considering the OAT was 80degrees.  Afterwards, dumped the oil while it was hot, therefore passing up the chance to check the post-flight oil level, but the first 3.5 hours used a half quart, which is great news.  The only issue during the flight was the crash of DU2, around the time I was switching localizer freqs on the SL30.  Will have to try to replicate the problem on the ground.  Learned how to reboot the DU afterwards.  Data logging seems to have worked fine.  Did not lean the engine at all in order to minimize heating, which hopefully accounts for pretty high consumption.

Fourth flight, 5/1/07, 2.0hrs: Phase I area.  More 24/24 flight.  Oil and CHT normal, rising slightly as I leaned out to around 1,400degrees.  Conducted the VSGV autopilot tests (pp7-9) of installation manual.  Reviewed the GRT airspeed calibration on p36 but did not do it.  Played with setting up for an ILS approach.  It seems that the SL30 is more sensitive than the GNS430 and when automatically selected it overrides a NAV 1 (GNS430) selection.  Prop seems to hunt on occasion, about 10~20rpm.  Slowed down way too early and maintained altitude at 14HG and prop forward.  Very good landing in 9kt winds variable.  Fuel tank readings are very unreliable -- almost useless.  When fuel flow option is set up I will get rid of the fuel tank readout on the engine 

Fifth flight, 5/1/07, 1.9hrs: Phase I area.  More 24/24 flight.  Governor started hunting at 2,400rpm, dropping to 2,370rpm and then back to 2,400.  Accomplished  GPS approach over OMH and tried to get to learn the ins and outs of the EFIS.  Too stressful working on it while flying in a pretty busy environment.  After flight, noticed a few streaks of grease at the base of the prop blades.  Also, noticed that the fuel level in flight is really off - having started with 21 gallons in each tank and getting a 16/16 reading on the gauges.  Did not fill up after the flight (dammit!), but gauges read 10/15 post-flight.  Does not square with 1.1/0.8hrs used, so will have to look into adjustments.

Spoke to MT about the hunting issue and was told by Douglas Turner to send the governor in for adjustment.  They are aware of the problem and will turn it around in 2 days, allegedly.  Will return to me as a -E model.  Says it's not a critical issue, and that it only happens around 2,400rpm.  Suggested running at 2,500 until I send it in.  Regarding the grease on the prop, Hartzell says it's normal and should go away after the first 15~20hrs.  Updated EFIS and AHRS software to 29d.

Sixth flight, 5/14/07, 1.6hrs: Phase I area.  More 24/24 flight.  Governor seemed to work properly.  Using Casey's EFIS instructions, I used the AP to fly a heading and altitude.  His altitude instructions were wrong, but I eventually got the usage right by setting VertAP to VS, not VNAV.  Use the DU left knob to select heading; for altitude, press the right knob once, twist to select desired altitude, press the knob again, set the climb or descent rate, and press the knob again to enter.  If the AP is on GPSS/GPSV, it responds as requested.  Performed two other of the experiments described in section 3 "autopilot coupling" and discovered that a localizer tuned on the GNS430 does not display a CDI on the DUs.  Something else to figure out with GRT.  Performed some steep turns that were very easy.  Discovered, however, that nowhere in the references does it say what the bank angle marks on the EFIS represent: 10, 20, 30 degrees, of course, but I need to confirm they are 45 and 60degrees.  Under calm winds, performed a flawless landing.

Seventh flight, 5/22/07, 2.0hrs: Phase I area.  After takeoff and during climb to 2,000ft at full power, the prop started hunting around plus or minus 30rpm.  Started Vy and best glide testing.  First attempt at 120KIAS using the autopilot went well; however the second attempt at 115KIAS did not.  First, the autopilot seemed to want to climb at 90KIAS, although I set it up for 115KIAS, and then the prop started hunting.  Aborted that test.  Both best glide tests at 84 and 81KIAS went well, but it takes about 1,000ft to get the airspeed pegged.  So, timing shouldn't start until 4,500ft.  I do hear some popping when I reduce power, even with the engine full rich.  With the ceiling coming down and a desire to see what is happening with the governor, I ran at 24/24, 25/25, and 26/26; rpm was steady at all these settings.  I used the time to do some performance tests.  Landed in a slight tailwind, bounced a little, and then defaulted to the nosewheel pilot mode and let the airplane drift to the right.  Caught it ok, but that was a totally unnecessary excursion due to proper lack of attention.

Eighth flight, 5/22/07, 0.7hrs: Phase I area, barely.  Propeller hunted again during climbout, and then in level flight at 2,400rpm, so I aborted.  MT's Juergen expressed great frustration at the trouble his company is having making a governor that works with a Lycoming/Hartzell combination and will get back to me in 2-3 weeks when parts for a new modification arrive from Germany.  Meanwhile, I am going to ground the plane and explore alternative companies' governors.

Ninth flight, 5/25/07, 2.2hrs: played around with the EFIS to settle on how to go direct to a VOR.  Uncovered some questions since I don't get a CDI with 430 VOR freqs, and with SL30 I get a CDI as well as a bearing pointer.  Did some pattern work at CJR and W66, making 3 good 3-point landings.  Landing at HEF went well too.

Tenth flight, 5/25/07, 1.7hrs: shot the GPS 14 approach into OKV using the autopilot.  Everything went well.  Returned to HEF and had a bad landing in a light right crosswind.  After a couple of bounces where I lost sight of the end of the runway and drifted progressively closer to the left edge of 16R, I went around.  The next landing was also a bouncer, but I was able to ride it out near the centerline.  The USB sticks did not record the data, as I exceeded the approximately 40 minutes of time each DU can hold the data.

Eleventh flight, 5/29/07, 2.6hrs: performed airspeed calibration runs using the GPS at 4,500ft.  See Excel spreadsheet "airspeed calibration May 29, 2007.xls.  EFIS- indicated true airspeed is 1 to 4 knots lower than that calculated during the calibration runs.  The steam airspeed indicator indicates 2 knots faster than the EFIS indicated airspeed.  After this test, practiced wheel landings at CJR with an 80KIAS final speed, 75KIAS over the numbers, slight down trim resulting in a need for a light back pressure on the stick (trim indicator at upper middle tick mark).  Got the first one right, bounced the next and went around, got the third one right, and the last one at HEF went well.  Speed is a little too high, evidenced by tendency to balloon in ground effect, so I will try 75KIAS on final and 70KIAS over the numbers.  Key is to release the back pressure when the wheels kiss the runway and address a small bounce by maintaining forward stick - back pressure increases AOA and the bounce.  Downside of the wheel landing is a long, long run; I exited 34L at A1.  Hopefully, slower approach speed and better technique will result in a shorter ground roll, but generally, the results are better than with my 3-pointers.  The principal reason, for me, is that I can see the whole runway when the airplane bounces and drifts off the centerline.

Twelfth flight, 5/30/07, 1.9hrs: did a direct-to CSN and then shot the VOR approach into Culpeper.  Confirmed a 2~3 degree lean on both PFDs while on a steady, autopilot-controlled, heading.  Also, got an EGT 4 alert for about 3 seconds without a corresponding high EGT readout -- confirmed by reviewing the data.  Performed slow flight 65, 60, and 55KIAS with 10 and 20 degrees of flaps, around 13/2,400.  At 30 degrees of flaps, immediately started to lose altitude and needed 15.5HG to maintain.  Obviously, 30 degrees is a big anchor; don't even want to see what 40 degrees does.  Performed stall test, finding it stalls clean at around 46~47KIAS, 46KIAS at 10 degrees, 46KIAS at 20 degrees, and 44KIAS at 30 degrees.  Stall break with no flaps occurred without warning, while with flaps there was a slight flutter through the stick.  Stall was pretty much forward, recovery very easy with releasing back pressure and adding a little power.

Worked on wheel landings with flare at 70KIAS.  Buildup was 10 degrees of flaps past numbers, pitch for 85KIAS, 20 degrees and 80KIAS on base, 30 degrees and 75KIAS on final.  11 to 10.5HG is sufficient until 30 degrees of flaps, and then at least 13HG and pitch adjustment is necessary.  Decent landing distance -- much better than flaring at 75KIAS.

When trying to select a VOR freq on the 430 to drive the EHSI.  Can't get a bearing pointer.  If select NAV1 as nav source on EHSI, toggle "CDI" switch to get "VLOC", twist OBS to get rid of annunciation, but no bearing pointer or CDI dots.

Thirteenth flight from W66 to HEF after refueling.

Fourteenth flight, 6/19/07, 2.4hrs: 6 wheel landings, last one best.  Was flaring too high and dropping it in.  Key to how much runway I use is precise flare; if I flare too high, time/distance is wasted inching down to the runway.  75KIAS on short final seems to work for now.  This was first flight with gear and wheel fairings.  Ball is half deflected to the left, whereas without the fairings it was touching the left bracket; this makes the PFD horizon lean a little.  Left rudder centers the ball and seems to eliminate the lean.  Got 164kts TAS at 25/25, which is pretty sweet.  Continued weird behavior of NAV1; I get a cross hair for ILS and CDI for VOR on the PFD, but on the EHSI I only get an OBS line and bearing pointer.  NAV2 is normal all around.  Shot coupled ILS approach into OKV per manual instructions (p20), and it tracked the localizer dead on but did not capture the glideslope -- I may have been too high.

15th flight, 6/21/07, 1.6 hrs: 2 wheel landings, last 20 degree crosswind at 5kts.  Performance tests.  Collected fuel flow data for the first time, but the numbers are way off.  Totalizer says I used 6.6 gallons, but I put 15.1 gallons back in the tanks.  GRT suggests reversing the flow to the flowmeter to make sure it's clean, and then trying it again.  I plan to perform a fuel flow test on the ground, as is, to see whether I get the 31 gph I got before the flowmeter was installed.  I'll then backflush it and see what flow I get.

16th flight, 7/7/07, 2.2 hrs: Vy and Vglide tests.  Also used the EIS lean page for a test run at 5,000ft at 25/25.  Heard a weird burbling sound once when throttling back for glide, and the usual smell which I assume is oil coming out of the vent tube and getting burned.  Also, hear popping when I go to idle for glide, and can even feel it through the floor.  GNS430 ceased to produce a sidetone when I press transmit at the end of the flight and Potomac approach/Manassas ground reported weak and unreadable.  Also, got intermittent RPM reading, especially after landing; determined that the mag P-lead shielding pulls out of the ring terminal, so I need to solder it in.  Rudder is centered pretty much throughout the flight, so the intersection fairings had a beneficial effect.

17th flight, 7/16/07, 1.8 hrs: pre flight, I replaced the 430 com 10A fuse and during the flight the radio worked completely normally.  Climbed out at 95 KIAS (Vy) and did not hit the CHT max of 450 degrees.  Performed solo stability tests per Van's instructions.  I had to keep my hand on the manual roll trim control to keep wings level during the test, as the left wing is slightly heavy.  At 23.6/25 at 6,500 ft, I raised the nose and let the stick go.  It took 4 full oscillations over the course of 4 minutes for the plane to stabilize in pitch.  At 80 KIAS it took 3 full oscillations over 2.5 minutes to stabilize.  The rudder is centered at cruise.  Applying hard left and right rudder, the plane made about 5 very quick oscillations before returning to center.  Later in the flight, after burning off about one hour's worth of fuel from the left tank, I performed the roll stability test.  In a 20 degree right bank, the plane returned to level when I let go of the stick (added a little up trim to compensate for the nose dropping).  On the left side, however, the plane stayed at 20 degrees, which I attribute to the "heavy wing" issue referred to earlier.  I will need to perform the aileron adjustment Van's refers to in the flight testing pages.  Lastly, I performed a flaps up stall.  The plane broke quick briskly and to the right at 49 KIAS with no buffet or warning.  I will have to repeat all the stall tests with a simulated passenger, but my sense is that the flaps up stall was somewhat more abrup than the ones performed with flaps down.

I did witness two false EGT alerts on the EFIS, both times "EGT 1", while the EGT readings were nowhere near the max of 1,450 degrees.  These events occurred at 0:47 and 1:18 flight time.  Looking at the recorded data, I found no anomalous EGT readings during these periods.  Both times they occurred there was no specific electrical event going on, like a radio transmission.  There appears to be no reason for these spurious alerts.

Finally, I leaned during most of the flight using the EIS lean page, resulting in apparently improved overall fuel efficiency. 

18th flight, 7/17/07, 1.4 hrs: conducted the same stability test as yesterday, but with two 80 lb sacks of cement in the passenger seat.  The takeoff roll was slightly slower and longer, and the "heavy left wing" issue was somewhat less than usual.  I thought it was because of my finger crimping of the right aileron, but a friend pointed out that it was likely due to the weight on the right side of the longitudinal axis.  Pitch stability was the same as solo, but at 80 KIAS it took 5 oscillations over 5 minutes to stabilize and the plane had climbed 500 feet.  Rudder test was same as solo.  Rolling to the left, both at 20 and 30 degrees, the airplane exhibited negative stability -- slow, but negative.  On the right, it was positive, although it took 2 minutes from 20 degrees and 20 seconds from 30 degrees.  These results agree generally with the Van's flight testing chapter.  Finally, I did stalls, but not wanting to crap myself, I aborted the flaps-up stall when the controls got mushy.  There is no stick shake in any stalls, but the flaps-up stall is very abrupt.  Leaned during cruise phases.

19th flight, 7/24/07, 2.1 hrs: conducted climb tests at 80, 75, 70, and 65KIAS.  It was hard to stabilize the speed by 2,000ft with a start at 1,000ft, so I had to start the timer at 2,500ft.  Next, conducted performance and fuel flow tests at 3,000 and 5,000ft.  Excellent stabilized approach and wheel landing in close to calm winds by coming in at 23/2,300, going to 15HG at 4 miles, 10.5HG at 2.5 miles, and 75KIAS short final.  Still did not make the A2 turnout on 34L; need to try short final at 70KIAS to shorten the rollout.

20th flight, 7/25/07, 1.9hrs: did some oversquare performance testing at 3 and 5,000ft, then full testing at 7 and 9,000ft.  Will need to redo the oversquare tests at 3 and 5,000ft because I inadvertently was LOP and the engine was not performing correctly.  Bounced the wheel landing, goddamit!  More training needed in pushing the stick on a bounce; just sitting there, or worse, pulling on the stick just doesn't work.

Note 1: Indications are with tail down, unless marked "level" which means aircraft is placed in flight attitude.

Note 2: Left tank's 1.1hrs was for takeoff, climbout, and cruise; so, 13gals for 1.1hrs of that kind of flight is 11.8gph.  Right tank was used for taxi, cruise, approach, and landing; so, 5..25gals for 0.8hrs is 6.6gph.  Need to find a way to check that there is no cross feeding happening.

Note 3: Reading varies between 16 and 17 for each tank in both tail and level attitudes

Climb test raw data: for 85KIAS thru 100KIAS, start at 1,000 ft, prop fwd, near climb airspeed, start timer at 2,000ft.  For 65KIAS thru 80KIAS, start at 1,000ft, prop fwd, near climb airspeed, start timer at 2,500ft because could not stabilize airspeed at 2,000ft.

Data adjusted to account for the timer for 65KIAS to 80KIAS tests starting at 2,500ft rather than 2,000ft.  

Best glide test: At 4,500 ft, prop at 2,500 rpm setting, throttle to slow to near descent speed, start timer at 4,000 ft.  70 KIAS provides the overall best result.  Using the V_{max endurance} = Vglide/1.316 formula, this means my best endurance speed is 53 KIAS, which is uncomfortably close to stall speed.  Also this means optimum cruise speed is 92 KIAS.

Oxygen use data

Governor replacement issue

- Gus at Van's: the problem I am reporting is, in his experience, specific to Lycoming-type engines that are modified for more power (such as with my 9:1 pistons).  He claims the problem does not exist with stock Lycomings or Hartzell propellers.  He states that the governor made by a Jihostroj and modified by Aero Technologies, called the PCU5000, has been reported by Van'sAF users with my problem as being suitable.

- Later, confirmed this on the Van'sAF site.

- Mahlon conversation 5/23: suggests some tests:

    - my description of the takeoff roll event (high rpm, then prop "bites") is somewhat anomalous.  

    - blade sticking test: on ground, run up to 2,200rpm and set throttle rpm is steady.  Cycle the prop 300rpm repeatedly, checking to see whether rpm return to 2,200 each time.  If not, may indicate a sticking prop

    - static rpm test: engine should run up to 2,650rpm during max power static test.  If not, adjust the governor arm stop screw (1 turn = 25rpm) until it does (see Hartzell manual p6-1).  After that, perform the low pitch stop adjustment described in the Hartzell manual on p4-4.  Hartzell manual has you do these test in the opposite order advocated by Mahlon.

    - during takeoff roll, note initial rpm at full power, then what happens to it when prop "bites".

    - during climbout, if rpm surges, nose over to level flight and see what happens.  During other surge events, change the attitude of the airplane and see what happens.  Also, to address issue of whether the higher power engine is causing the problem, reduce throttle setting (such as to 23HG when surge happens at 24/24) and see what happens.

    - check that max rpm in flight is 2,700rpm

    - try to note oil temperature during surge events, although temp of 208degrees is not noteworthy.  MT governor may not be producing sufficient pressure when the oil is hot.

- Received call from tech at Aero Technologies who says the PCU5000 will solve the problem, and who says there's a group buy in progress.

- Found the thread to the PCU5000X group buy, and ordered one from Bob Honig.  Removed the MT governor in preparation for the PCU5000X which is inbound the next day.

- Installed the PCU5000X.  Had to install the nuts on the studs first, then set the studs.  No leaks, and the governor holds RPM at all times after 6.5 hours of flying.  Later, finding tendency that makes it hard to set rpm to 2,500 and 2,600 rpm.  Typically, turning the prop control seems to have no effect, and then rpm overshoots the intended setting.

Questions

what happens to rpm, sounds, etc... when turn off E-ignition in various conditions?

incorporate E-ignition fails, turn off mag, engine quits, go to idle cutoff, wait 10 seconds, mag on, slowly enrich till engine start

General parameters

oil temp 110-180 degrees. CHT, 220-350 degrees.; idle at RPM as low as possible; cycle prop to max 300 rpm drop

full power takeoff, flat climb, reduce to 85% in climb, reduce to 75% at pattern altitude

no more than 15% above temp restrictions (so, 400 degrees CHT, 205 degrees oil temp)

no less than 150 degrees rich-of-peak at 75% power

cool down at 1,000rpm for 5 minutes

change oil after 5 hours, 25-30 hours, 35 hours, then every 50. Ignore oil sample testing first 2 or 3 times

- at 13.4 hrs, seem to be using around 6 qph, which is looking good.  Mahlon says to run at 75% for another 10 hours.  Says pattern work is not a problem, just watch the temperature.

- at 30.4 hrs, holding at 6 qph.

Suggested solutions to high CHT

- seal space between baffles and engine better

- make adjustments to cowling inlet deflectors: make deflectors, seal the sides

- rejet carb for richer mixture

- adjust advance of electronic ignition

- cleaning out the flashings in the fins between the spark plugs

- louvers (Avery) on lower cowl

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