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 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:

 

 

Spark Plug Cables

Something I have been pretty picky about is the routing/mounting of the ignition system. This process started a probably a year ago at this point but started finally coming together in December when I was finally able to securely fasten the coil packs in a position that was both secure and cleared the cowl. 

I have seen a lot of planes (or at least photos of planes) with people bundling the plug wires on their electronic ignitions. While I am not sure how important it still is in modern plug wires to separate cables by at least 1/4" I made the decision early on that I wanted to isolate individual plug wires. 


 

I did end up ordering a lot of spare hardware from Summit and Amazon that I ended up not using as I was trying different wire layouts. As a base, FlyEFII sends 2x Taylor 8mm Spiro-Pro cable kits along with their System 32. I stuck with those cables as they seemed to be pretty nice quality. I swapped out the coil pack ends from that kit with Taylor Cable 46051 90 degree low profile HEI boots. I ended up doing that for two reasons. First, FlyEFII sends enough hardware to do the 12 plug cables. I always like to have extras prior to starting so I was going to be ordering another set of plug boots anyways. Secondly, I centered the coil pack bracket on the engine mount cross bar. In doing this, the coil packs are a bit close to the baffle. While the standard locking boots still fit in this space, the low profiles make it just a little bit nicer to service the forward facing boots.

In order to secure the cables I used 2 packs of 42700 as well as 2 packs of 42502 cable separators. The 42502 have standoffs included with them.

  

FlyEfii Coil Bracket

If you remember when I got my System32, I struggled with how to mount the 3 coils forward of the firewall. A lot of people had just been using Adel clamps to secure the coil pack to the engine mount. The coils are surprisingly heavy though, and I think far too heavy for adel clamps. At the time, I had found some great bar mounts that I had milled and modified to fit my application. I was really happy with that however when I went to go install the cowl top, they coil pack was sitting too high and touching the cowl top.

With that, my new coil pack design had three goals. 1) securely mount the coil pack to the top bar of the engine mount with ubolts. 2) If possible, get some vibration dampening in the mount 3) Keep the coil packs as low as possible so they did not touch the show planes cowl.

To accomplish these goals, I ended up with a plate that allowed the coil pack to pass through the plate allowing me to put the coil pack at a minimum distance above the actual bar.

I drew this up in Fusion 360.


Then put it on my router table in the basement.



I did cheat and mill this out of plywood twice because I didn't want to destroy the $100 chunk of aluminum. The final product though is shown below.

I secure this to the top bar of the engine mount with three cushioned stainless u-bolts from mcmaster.

I could not get the fourth one because of the intersection of two bars right where I wanted to put a u-bolt.


The final product however was perfect. The coil packs are secured to the plate with 3 AN-4 16 bolts and 3 washers standing them off of the bar by 1/8".

Fly EFII ignition mount

I went with the FlyEFII System32 ignition (dual). They have a nice bracket for the coil pack, but this makes a pretty hefty assembly that needs to be mounted. There are various things people have done to mount this pack and most of them include standard adel clamps. I wanted something a little heavier duty, because this is a pretty heavy assembly. I ended up finding a light bar mounting bracket off of House Tuning that worked perfectly. This is the standard 7/8 tube rubber isolated light mount.

The coil pack holes accept AN-4s but the light bar mounts are 3/8s (or maybe even 5/16s). I placed a mcmaster order for some bushings (under bearings at mcmaster) to take the 3/8s holes and adapt them. The bushings didn't fit, so I reamed out the holes.

And then shortened up the bushings a bit.

This allowed me to install the front two mount points of the coil pack right behind the aft baffle on the main cross bar.

This looks like it is going to be perfect for the plug wire spacing (at least I hope so because anything other than this is going to be kind of a pain.

The last thing to do is make one hard mount point for the aft of the coil pack going down to the angled bar. I will do that another day. I am either going to come down the the angle bar, or I am going to install one of the bar mounts facing aft and flush mount a screw through the coil pack plate. For now though, it is pretty dang solid.