Vy Calibration Runs (Sawtooth Climb Performance)

While this is not complete data by any means, this session allowed me to get used to the procedure while at the same time not getting bored just running around in cruise circles. I need to repeat this session with 0 degree flaps as soon as I get the wheel pants on. Also, yes, I do have an EFIS that is recording at 1Hz and the abbreviated method of this calculation would be faster. That said, I am in Phase I and I am taking into account that it benefits me to learn the plane while still close to the airport, so longer procedures are not an issue. Calculations were based on this method. OAT was 6C at altitude and the airplane starting conditions had me weighing in at 2230lbs.

I ended up doing x8 valid 60 second climbs dropping the indicated air speed 5 knots per run. I started with 120 KIAS and ended at 85 KIAS. I still need to take this down to 75 but I want to run the power on stall tests before going lower. The figure below shows the 8 runs (the first one I am removing from the data set because I forgot to set a timer). The top sawtooth graph is Autopilot IAS versus Indicated Altitude. The bottom graph is KIAS versus Vertical Speed. A reminder on Vx and Vy. Vx is the slowest (IAS), and is the Maximum ANGLE of climb.  It allows one to climb to altitude within the shortest horizontal distance. Vy is slightly faster, and is the Maximum RATE of climb. It allows one to climb to altitude in the shortest time.

<todo: get the excel diagram output here>

Below are the calculated angles as defined by Google Earth Pro:

Test Flight 4: Auto-pilot, Vx, Vy, Engine Leaning in cruise

Test Flight: 4

Date: Saturday January 30th 2021

Hobbs Start: 5.0 Hobbs End: 6.7

Description: A very busy airspace, but overall productive flight. With extended time on the ground I worked on ground leaning procedures a bit and that turned out well with a very clean ignition check. Each ignition was a drop of 50 or so. Audio recording finally worked, but a couple of notes on that. My helmet ANR was set for mono, 3D audio on the GMA245 was on. I changed those two settings as well as unplugged and plugged my phone in after the audio panel was booted and everything finally started working. CHTs came down a good 50 degrees from the previous flights. My max CHT was in the 345 range on a WOT 85 knot climb. I ran a slow injector data gathering leaning run. My injector spread is .8 GPH. I will run that again before I start swapping out restrictors. Climbs were awesome being able to hold stable at +2000 FPM without hitting CHT overtemp. (it was 46F though)

Objectives: Fuel topoff, preflight and run-up of the aircraft, normal take off with 0 degree flaps, depart the pattern for engine break in, auto pilot deployment, verification of squawk resolutions (max RPM, Autopilot servo configuration), engine leaning data gathering, race track Vx and Vy runs (1 minute pulls), return to base, normal full flap landing.

Airplane Start Condition: 60 gallons of fuel, 10 qts of oil as read on the dip stick (fresh after oil change) , 50lbs of ballast in the baggage compartment, single pilot (150lbs)

Airplane End Condition: 38.4 gallons of fuel, 9 qts of oil as read on the dip stick (A lot of this went to the oil filter), 50lbs of ballast in the baggage compartment, single pilot (150lbs)

Test Flight Track Log:

Pilot Notes:

1) Max RPM on takeoff was 2700. The governor appears to be perfect now. Also adjusted the cable itself and got rid of the play at the full forward end.

2) Autopilot HDG, ALT, YD modes function well. Used the following settings:

Roll Servo
Servo Direction = Normal
Max Torque = 75%
Servo Gain = 0.80
Fine Adjust Time = 0.20
Fine Adjust Amount = 0 (disabled)

Pitch Servo
Servo Direction = Reversed
Max Torque = 100%
Servo Gain = 2.50
Fine Adjust Time = 0.20
Fine Adjust Amount = 1

Pitch Gain
Min Airspeed Limit = 70 kt
Max Airspeed Limit = 180 kt
Vertical Speed Gain = 1.40
Vertical Accel Gain = 1.00
Airspeed Gain = 1.35
Airspeed Accel Gain = 1.00

Yaw Servo
Servo Direction = Normal
Max Torque = 100%
Servo Gain = 1.50

Manual Electric Trim
Airspeed Threshold = 80 kt / 140 kt
Roll Trim Motor Speed = 100% / 50%
Pitch Trim Motor Speed = 100% / 50%

3) CHTs really came down. Pushed the engine hard for VX VY testing and only saw 379 as a max CHT on a 85 KIAS climb.

4) Worked on engine leaning at cruise. Got some good data on EGT/CHTs on leaning again. My Fuel Flow spread is .8, but I think I need to take a look at cylinder 2 and see if perhaps that injector needs a cleaning before I start messing with restrictor sizes.

5) There is something weird with recording the audio if the phone is connected before the plane is powered. Reset the connection after the avionics were powered and everything was fine. Also though I turned off 3d audio and flipped my helmet to stereo opposed to mono mode.

6) Flew some initial Vx and Vy tests. Used 4500ft as my floor, would stage at 4000, set the auto pilot for an IAS climb, mixture forward, prop forward, power forward. Upon crossing 4500 when stable, start a 1 minute timer. After 1 minute drop back down to 4000ft while turning to the reciprocal heading and starting over again.

7) I realized after doing this that I did these runs in Reflex mode. Re-run this test again with 0 flaps.

Open Squawks:

1) COM2 breaking squelch on COM1 TX. COM2 sensitivity weaker than COM1. COM2 could use a ground plane.

2) Need to set "Flight" vs "Ground" calibration on the fuel levels. 

5) While the charging system is stable, I would still like to see if I can get the 0.2v differential out of the x-feed contactor. That is, my AUX bus when the alternator is on runs at a voltage 0.2v lower than MAIN. It is not that surprising given the number of connectors between the two busses. In order for the AUX battery to get alternator voltage it has to get through terminals on the MAIN contactor, X-FEED contactor, and then the AUX contactor. One or more of those terminal to terminal connections needs to be cleaned. 

Verified Closed Squawks:

1) CHT1 is no longer the hottest cylinder. Cut back the Right air dam and now Cylinder 2 is the hottest but the spread is much smaller. Going to run it like this for a while.

2) Max RPM on takeoff was 2700. Proper Governor Max RPM is good.

3) Flaps are now configured for position based deployment. Confirm working well

4) Autopilot servo settings are holding heading and altitude well

5) Changed oil at 5 hours to 65

6) Added Tanis pre-heater system.

Test Flight 3: Rough Pitot check, Autopilot squawk correction, engine break-in

 

Test Flight: 3

Date: Thursday January 21st

Hobbs Start: 3.3 Hobbs End: 5.0

Description: Third flight of the aircraft. Straight up the most chaotic flight I have had as a pilot and even the first real (non-practice) go-around I have done. The flight was a bit adhoc because I was needing to change my oil based on winter finally arriving, but then we ended up getting a 60 degree day and I decided to run over and get a flight in. (I couldn't find 65 Mineral Oil this week and the temps at night dropped down to the twenties). The pre-flight started with an iPad update taking my device off of the cell network. Following that was in the 30 minute window I tried to depart, the tower (where we get our DC SFRA codes from) had shut down due to an unplanned COVID19 screening. 2 of my cylinders were acting up on the run-up (but cleaned up after burning off some carbon). My transponder did not go into ALT mode automatically (probably because I switched it to 'ON' while on the ground), so I almost got turned around until we reset it. I was attempting to conduct some tests of the pitot system in various flight configurations, but due to traffic like I have not seen before could not make a straight line for more than 30 seconds at a time (look at the track log). It took about 6 calls to get a SFRA clearance to come back in, and then when I got a squawk I had to orbit only for them to release me from my code thinking that I was outbound not inbound after they lost track of me. Then finally on landing I bounced it and chose to make a go-around. (I came in full flaps, but 80 is definitely too fast over the numbers with full flaps). I was fighting cross wind gusting but then in the go around I realized why everything felt so weird. I turned off autopilot right before base to final and given the wind conditions I ended up with heavy left aileron trim. I probably flew too short of a final to figure out what was wind, where some of the control forces were coming from, etc. Anyways, no harm, go around went just fine to a nice greaser landing. 

Objectives: Fuel topoff, preflight and run-up of the aircraft, normal take off with 0 degree flaps, depart the pattern for engine break in, auto pilot deployment, verification of squawk resolutions (autopilot pitch trim direction reversal, fuel level readings), clover patterns comparing Air speed to Ground speed and recording that with measured wind, initial engine leaning data gathering, return to base, normal full flap landing.

Airplane Condition: 60 gallons of fuel, 8.5 qts of oil as read on the dip stick, 50lbs of ballast in the baggage compartment, single pilot (150lbs)

Test Flight Track Log:

Pilot Notes:

1) Max RPM on takeoff was 2720. 

2) Autopilot HDG, ALT, YD modes function. Altitude wanders 100ft in turns and heading hunts 5 degrees or so in a direct cross wind. Heading holds well in head and tail winds. Need to fine tune the servo settings at some point.

3) Fuel gauges were more functional than last time. Need to re-calibrate again for proper flight attitude. I believe that my initial calibration of the 20 gallons and below was at the wrong attitude.

4) Worked on engine leaning at cruise. Got some good data on EGT/CHTs on leaning. I need to cut down the air dam on the right side before I continue this further as the CHT1 still warms up a bit more than everything else. Will work injector balancing later in the program.

5) Screwed up audio recording again. I am using the bump in the wire from NFlight which has always worked on other aircraft, but it does not seem to be picking up audio as soon as the TX button is depressed. Stereo vs mono? Something with 3d audio? Bad connector somewhere?

6) 80 knots over the numbers with full flaps is still fast. I will feel better about reducing this number after in air stall tests. The stick was back pretty far in the flare and while fighting the cross wind gusts I ended up with a light bounce. I ended up going around just because why not.

7) Need to parse the data on the airspeed calibration runs, but from my counting with finger math during flight the air speed at least at the tested speeds was spot on.

8) Left tank vent may need to be moved up a bit. May have just been the ramp angle, but after the fuel truck topped me off the left vent vented more fuel than I like to see on the ground. (a) warn the fuel truck guy next time to stop a little lower (b) check where the vent is relative to the right tank vent

Open Squawks:

1) COM2 breaking squelch on COM1 TX. COM2 sensitivity weaker than COM1. COM2 could use a ground plane.

2) Max RPM on takeoff was 2720. Proper Governor Max RPM needs adjustment

3) CHT1 is still the hottest cylinder. The spread is only 40 degrees from hottest to coldest, but CHT1 could probably benefit from some additional right side air dam reduction

4) Fuel tank level curve is much better, but need to set "Flight" vs "Ground" calibration. 

5) While the charging system is stable, I would still like to see if I can get the 0.2v differential out of the x-feed contactor. That is, my AUX bus when the alternator is on runs at a voltage 0.2v lower than MAIN. It is not that surprising given the number of connectors between the two busses. In order for the AUX battery to get alternator voltage it has to get through terminals on the MAIN contactor, X-FEED contactor, and then the AUX contactor. One or more of those terminal to terminal connections needs to be cleaned. 

6) Move the flap deployment from momentary to position based now that I am comfortable with full flaps.

7) Probably our last 60 degree day. Swap the oil out for some 65.

Test Flight 2: Engine break-in, initial full flap deployment, initial autopilot powering

 

Test Flight: 2
Date: Monday January 18th
Description: Second flight of the aircraft
Objectives: Extensive preflight and run-up of the aircraft, normal take off with 0 degree flaps, verification of squawk resolutions (oil door, alternator belt, prop governor max RPM), depart the pattern for engine break in, initial auto pilot deployment, initial flaps to 100% deployment, return to base, normal full flap landing.

Airplane Condition: 60 gallons of fuel, 9 qts of oil as read on the dip stick, 50lbs of ballast in the baggage compartment, single pilot (150lbs)

Test Flight Track Log:

Pilot Notes:

1) Max RPM on takeoff was 2720. One more rotation of the max rpm set screw should be sufficient

2) CHT1 started getting warm on a 105KIAS climb. Probably would help to cut the air dam back more, but also the climb was a bit steep. Maybe more around a 120KIAS climb would be sufficient.

3) Autopilot initial deployment indicates that the pitch trim direction needs to be reversed, autopilot twice in a row ended up in a pretty steep nose down pitch trim attitude about 10 seconds after enabling. Yaw damper and Heading modes seemed to work perfectly, but it was a bit hard to tell when the pitch trim was trying to kill me.

4) I had the tanks topped off for this flight. Configuration of fuel levels with full tanks was pilot error. I set calibration points on both the left and right tanks at 60 gallons per side by accident. That threw off the curve to the point where fuel gauges were not accurate.

5) Screwed up audio recording again. The new sony recorder was not picking up the mic input. Audio in video was from liveATC

6) 80 knots over the numbers with full flaps seems a little fast, had a long time over the runway and was fighting the float. I will lower this speed down after I get good stall speed numbers.

7) During runup, left ignition had a drop of 200 RPM, two cylinders looked to have fouled plugs. Ran for 10 seconds at 55% power while leaning for max RPM. That cleaned up the EGTs and mag check was back to matching the right side after that. I have been been running too rich, no doubt there. I have been focused on CHT numbers, but will start testing leaning on the next test flight. Also need to lean for ground ops.

8) Used Left tank for takeoff. The first flight I used Right. I have been making some steeper banks, but I should test right turns next flight.

9) COM1 audio is great. The COM2 antenna needs a ground plane. COM2 RX/TX is fine when the other side is in range. Everyone reads my 5/5, however two things. COM2 will break squelch from COM1 TX depending on selected frequencies. Also COM2 has just a touch less sensitivity when trying to get things like ATIS from the air from afar.

Squawks:

1) COM2 breaking squelch on COM1 TX. COM2 sensitivity weaker than COM1. COM2 could use a ground plane.

2) Max RPM on takeoff was 2720. Proper Governor Max RPM needs further adjustment

3) CHT1 is still the hottest cylinder. The spread is only 40 degrees from hottest to coldest, but CHT1 could probably benefit from some additional right side air dam reduction

4) Fuel level curve is out of sync with reality. Delete the 60 gallon erroneous calibration points and re-calibrate 30 gallons on each tank before next startup.

5) Autopilot pitch trim running away. Reverse autopilot pitch trim direction.

6) While the charging system is stable, I would still like to see if I can get the 0.2v differential out of the x-feed contactor. That is, my AUX bus when the alternator is on runs at a voltage 0.2v lower than MAIN. It is not that surprising given the number of connectors between the two busses. In order for the AUX battery to get alternator voltage it has to get through terminals on the MAIN contactor, X-FEED contactor, and then the AUX contactor. One or more of those terminal to terminal connections needs to be cleaned. 

Garmin Aviation Log Parser

Two flights in and I already got really annoyed at building excel charts for my Garmin engine/air logs. I started a new git repository for anyone that wants to work with me here, but it is pretty easy to get from Garmin CSV logs to interactive standardized charts using a little python and the plotly library. 

Here is the repository link if you are interested: GitHub

Test Flight 1: First Flight!

 

Test Flight: 1
Date: Sunday January 10th
Description: First flight of the aircraft
Objectives: Extensive preflight and run-up of the aircraft, high speed taxi / aborted takeoff, normal take off, initial systems checkout while in the pattern, depart the pattern for engine break in, return to base, normal landing.

Airplane Condition: 40 gallons of fuel, 9.5qts of oil as read on the dip stick, 50lbs of ballast in the baggage compartment, single pilot (150lbs)

Test Flight Track Log:

Test Flight Report:

 

 

DAR Inspection

After a lot of back and forth with the FAA/FSDO(s) (months) I was able to finally get an appointment to get N5412K inspected. Yes, it was a lot of paperwork, no doubt about that, but the process was more or less straight forward on my side of it. I think all of the DARs are struggling with the new AWC application system, but that is a different story.  I felt fairly well prepared and didn't run into anything that I completely missed. The short of it, N5412K now has an airworthiness certificate. 

The one thing to really watch for in this process is the actual text in the Phase II kinds of operation. We had to go back and forth a couple of times with the DAR (the new AWC process) in order to ensure that all of the language was correct in order to get VFR, Night VFR, and Instruments defined in Phase 2 Kinds of Operation. Thanks to the RV10 community for helping me with the exact language to look for.

The process itself was more or less how all of the other blog posts read. Once I was able to find someone that was able to come out, we started the conversation about 30 days prior to the actual inspection. The DAR sent me a checklist of things that he was going to go through and I reciprocated with sending this blog URL with the caveat of "this blog is not actually my build log, I have a real build log." 

The process itself was fairly quick. It was more or less a very comprehensive pre-flight (with the inspection covers off) with in-depth inspection into some key areas that I am assuming that either are personal importance to the DAR or pushed down from the FAA. I had two tables with my build logs, the paperwork, the photos, the invoices, etc. We didn't really dig much into each individual entry, but when I scrolled through my photos and electronic build logs the DAR was satisfied that I met those requirements probably purely on the size of the folders. The plane itself had its main root fairings, inspection covers, cowl, baggage bulkhead panel off. For the items of the plane that where not immediately visible I did have photos of every mechanical connection for the things that I did not have access to. For instance I did not have any of the tunnel open or the seats out, but I had photos of every linkage, fuel system fitting, brake system fitting, and electrical connector for anything that was not immediately visible. As a backup I did have an endoscope camera ready to go just incase there was something we wanted to see that I did not have a photo for.

When the DAR sent over the checklist, I did ask a couple of questions and had photos in those questions to make sure things like my ELT antenna placement were going to be acceptable to him. The other common things that everyone else has said/argued I made sure were a non-issue. i.e. Control stick contact with anything, the availability of a Whiskey Compass, etc. The only unexpected thing that happened was the night before the inspection the FSDO asked for the Kit Built checklist. The DAR felt bad about this because everyone knows the RV10 is already on the approved kit list, but we made the decision that fighting it was not worth it, it was easy enough to complete and submit rather than argue.