Chapter 27 - Section 5

Phase 1 Testing Experience

After going through the DAR inspection and First Flight (by my test pilot), we all naturally assume Phase 1 testing shall commence. I have gathered (and read) many Phase 1 test plans and started my customized Phase 1 test plan as well. The day of reckoning arrives when you start thinking about climbing into your plane that was flown only once by a VERY experienced pilot. I am going to take it up next...???

First of all, I am a low-time pilot, and I have not kept up with flying for the past 12 years (i.e. throughout my building years). Technically, I am not even legal to fly because I allowed my biannual to lapse. I did, however, plan ahead to get my medical certificate. Then I signed up with a local flight school to brush up on my ground school knowledge and flying. It took me close to 15 hours, flying a Cherokee, to get my biannual signed off as well as familiarize myself with various procedures here at the Chino Airport. After many more hours of flying accompanied by a competent canard flyer, I learned to transition from a Cherokee to a Cozy... A Cozy is certainly a very different flying machine! I have to shed a few 'bad' habits accustomed to flying a Cherokee in this transition period.

Phase 1 Sand Box

Once my Cozy was considered 'air worthy' by the DAR inspector, I was assigned a 12-mile square Phase 1 test area. Since my home base airport (Chino Airport KCNO) is in the midst of the Los Angeles basin, my assigned Phase 1 Test Area (sand box) has to be clear from congested areas. In my case, my sand box is 50 miles from the Chino Airport. It sounds a bit illogical that I have to fly 50 miles to play in a 12 mile square sand box. Regardless, I followed the assigned rules and performed almost all my climb, descend, stalls etc. inside my sand box.   

The second unexpected diversion, as I soon found out during Phase 1 testing is that - fixes and refinements need to be done to the plane, and re-test before moving forward. Subsequently, my Phase 1 test phase is more like a stop and go process. Here's a few of my work in process fixes...

Roll Right Tendency

After several flights, I noticed my plane has a tendency to roll to the right. Since I have Bill (my test pilot) with me (he is ~60lbs heavier than I am), it was suggested to me that I should wait before making any changes / refinement to the plane. Since I have a positional feedback trim actuator, I can see my trim position on my EFIS. I was surprised to see that my trim correction was quite large. After much checking, I learned that I should set the mid-point of my actuator at aileron neutral position INSTEAD of mid-point of up-most and bottom-most travel. That seemed to make it look much better on screen.

After flying many more hours solo, my plane continue to have roll right tendency. I decided to add 1/2 thickness washer to the top two right wing bolts and 1/2 thickness washer to the bottom left wing bolt. Since then (half way into my Phase 1 testing), my plane can be easily trimmed straight & level (hands off) with ease. As expected, addition of the two washers leaves a noticeable seam mismatch between the leading edge of both wings and the main spars. I flew with that configuration till I reached 150 flight hours - just to be sure of the leveling characteristics. This mismatch affects both the top and the bottom seams of the wings and the strakes.

Battery Running Down Frequently

Early on my Test Phase 1, I experienced low battery level that keeps me from starting the plane. My first thought was that I had this battery (Odyssey 680) for several years while it sat throughout my electrical and electronic installation process. The battery was never 'topped off' periodically as I should have. Therefore, it lost its holding power.

My second guess was that I have not figured out the best 'setting' for starting my plane at that time, thus the extra cranking just sucked up all the juice out of the 'already weak' battery. I finally went and bought a new Odyssey 680 and an appropriate charger (from Odyssey). It was better, but the battery level still seems low if I do not 'top it off' every week or so. In parallel, I charged up the old battery and monitored its discharging rate. To my surprise, the old battery was holding its juice for an extended period with nothing hooked up to it. I concluded that something in the plane is draining my battery...

I finally realized that my remote control for my canopy lock & push up actuators are connected to the un-switched side of the battery. The remote control (key fob) has to be powered on (ready mode) at all times, thus slowly draining my battery. I added a push button switch (accessible but hidden from outside the plane) to disable the remote. Problem solved! My battery is healthy again.

[Hindsight] Once I figured out a procedure to start my engine (Ref Chapter 27, Section 06), it generally starts within a couple prop rotations. That eliminated much of the battery drain as experienced in the past. In addition, the "hidden" remote disconnect to the remote control proved to be correct. My battery hardly needs any recharging between flights throughout the rest of my Phase 1 period and beyond.  

Stuck Mic

On my third or fourth flight, I was experiencing a stuck mic phenomenon. When I released my PTT button, the mic stayed on the transmit mode for another 20 seconds before it released. Obviously, the control tower did not appreciate it, besides, it was embarrassing. So, I have to ground the plane until it is fixed.  It only occurs on the pilot side and not the co-pilot side. That sounds like an easy fix, so I thought... Since it only occurs on my side, that could only be caused by the grounding on my mic plug or stuck PTT button on my control stick. Turned out to be none of the above. Took a lot of effort to narrow it down to my PS Engineering radio control panel unit. Borrowed Clark Canedy's PS8000 unit and made a swap - problem disappeared. Returned my unit to PS Engineering and was repaired (they replaced 4 components) and shipped it back out after 2 hours from arriving at their shop. My guess is that they were aware of the problem. Regardless, this problem stopped my Phase 1 for an extended period.       

Erratic Fuel Pressure

After approximately ~25 Tach hours on my engine, I noticed my fuel pressure (with mechanical fuel pump on only) dropped from 27 psi to 21/22 psi from time to time. After a while, the fuel pressure will climb back up to 26/27 psi. This phenomenon is a bit unsettling especially in-flight. Turning on my electric fuel pump will push the fuel pressure back up to acceptable level (25-31 psi range). I know some Cozy fliers leave their electric fuel pumps on throughout their flights. I prefer to leave my electric fuel pump as a backup and use it for take off and landing only. That way, I'll know my mechanical fuel pump is functioning accordingly at all times.

I was puzzled as to what may be the cause? Failing mechanical fuel pump? Vapor lock as suggested by someone in the Vans Aircraft Forum? Or is it just normal? Should our fuel pressure number be solid throughout? The general consensus is that if my fuel pressure stays above 20 psi, I should be ok. However, a drop in fuel pressure in flight is rather unsettling (for me anyway). I know some will say – just replace it. However, inquisitive minds would like to learn if otherwise… 

Just for reference, I have an IO-320 Lycoming with 10:1 compression ratio, one Lightspeed Plasma 3 CDI electronic ignition and one Slick magneto (P/N 4371). My mechanical fuel pump is an overhauled LW-5473. My electrical fuel pump is Airflow Performance Boost Pump (P/N 3090050) with fuel filter (P/N 1090079).  My fuel pressure sensor is VDO 360-003 (80 psi) connected to GRT EIS 4000. Settings at the EIS are AuxSF = 91 and AuxOFF = 15 per their installation instructions.

The first thing I checked was my fuel filter inside my electric pump – it was clean. Then I checked the insert orifice in the fuel pressure sensor line, it was clean and not clogged. I checked my electrical wiring – they were secured and the body of the VDO is well grounded. I also checked the torque values (30 in-lbs) on the spring lock ring at the bottom of the mechanical fuel pump per Textron/Lycoming’s SB#525A. I reviewed my flight data (recorded via my GRT EFIS) and cannot find any correlation between the FP declining trend to the RPM, altitude, MP and CHT.  

Out of ideas, I finally decided to replace the VDO unit with a Grand Rapids Stainless Pressure Probe Part # 11-09545. So far, my fuel pressure on the ground and in flight has been more stable. Its reporting consistently between 24 to 25 psi. I consider the problem solved... time will tell.

[Hind Sight] It was a good decision to change out to the new Fuel Pressure Probe. Evidently, Grand Rapids received many complaints and returns on the original fuel pressure probes they sent out as part of their EIS kits..

Learning to Use EFIS

I installed a dual GRT Hx EFIS in my instrument panel. It has lots of display functions. It took me many hours just to figure out how it communicate with the rest of the instruments with the appropriate baud rates etc. Once connected, I have to set what, how and when these information are displayed. When it was all working - I got information overload. While learning to fly the plane, all the information displayed on the EFIS became a distraction. I decided to turn off all the 'goodies' except the basic essentials. I flew my Cozy for a good 15 hours before turning some of the 'eye candies' back on.   

Wheel Pants Caught by Wheel?

You can find many discussions on wheel pants getting caught by the wheel on landing in the Cozy Forum. On one of my landings - probably in the 30's, I heard weird noises as I applied my brakes on landing. No yaw or drag on the plane as I taxi back to the hanger. Initially, I thought a bolt may have gotten loose - bouncing inside the wheel pants.

The next day, I decided to remove my wheel pants to check out my brakes. It looks like the my right main caught the rear edge of my wheel pant opening (Pic #1). and ripped a piece of the glass backwards (Pic #2).  In that few seconds of contact between the glass and the wheel, it melted some of the surface rubber on the wheel, splattered the 'tar' like material all over the inside of the wheel pants (Pic #3). I used Simple Green cleaner to remove the 'tar' like substance, all is well. Then I trimmed off the ripped fiberglass and patched it back up with 6 layers of criss-cross UNI (because I ran out of BID), (Pic #4). Floxed in the edges and peel plied (Pic #3). After cure, I brushed on my primer (Pic #5) and all is well again. I also cut back the opening by ~1/4" (towards the back).  I have made approximately 10 landings since the repair, so far so good.

[After Thought] I showed my wheel pant destruction to a few experienced Cozy/Long EZ flyers. We are all surprised why it occurs after so many landings - it was not a bad landing. Some suggested that the wheel may have picked up a rock on landing and flung the rock up, hitting the bottom of the wheel pant. The ripped glass strip in turn swung upwards, making contact with the tire. All in all, it was a new experience for me.   

EGT Temperature Probe Jitters

After multiple flights (approximately 35 hours), my #1 EGT temperature probes started to report erratic temperatures in flight. It jumps between 200 to 1200^oF every other second. From past flight experience, I know my #1 EGT is always the lowest - thus NO panic! My suspicion is that a crimp connection has come loose. After landing, I removed my cowlings and traced through my #1 EGT electrical connections (I am glad I labeled all my wires...) - sure enough, my crimp wire came right out. I am certain that I performed a pull test on every crimp connection, how it ever got loose is a mystery to me. Lesson learned - never underestimate what vibration can do to your joining materials (such as bolts, nuts, electrical connections etc.). Re-crimp and re-test fixed the problem...for now.      

Excessive RPM drop with Electronic Ignition

As a standard procedure, we all perform an engine run up before each flight by switching and turning off the electronic ignition and the magneto (for my installation) alternatively and observe their respective RPM drop. On one occasion, my electronic ignition dropped 230 RPM during my Mag check (both with mixture full or leaned). I decided to abort the flight and return to the hangar for further investigation. Unfortunately, this phenomena was not repeatable.

Since then, this occurs once in a while during run up and I have aborted several flights due to this phenomena. What if this occurs in flight? I decided to ground the plane and spent months going through the troubleshooting guidelines per Light Speed manual. I replaced the spark plugs, spark plug wires, re-made a new set of primary ignition wires, replaced ignition coils, replaced manifold tygon tubing etc. - all with no success. I finally gave up and gathered all my documentation/test data and sent them to Light Speed (Mr. Klaus) in a long e-mail. Then I removed my Light Speed unit and paid Klaus a visit at his home base (Santa Paula). I was greeted with a warm welcome. He opened up my unit at his shop right away and performed a series of functional tests on my unit at his work bench. Did not take long for him to find the problem - the female BNC connector receptacle (for Channel A) was wedged open/loose, thus making intermittent contact with the male pin (mating BNC connector) from the primary ignition wire. He quickly replaced the female BNC connector in the unit and I was good to go again! Simple fix but extremely difficult to find for sure. This set me back 3-4 months of Phase 1 effort.   

High Manifold Pressure at Idle

With my engine running reasonably consistent again, I returned to my Phase 1 testing effort. Some point in time, it was pointed out to me that my manifold pressure at idle is running a bit high. My manifold pressure normally runs around 13-14 psi. Normally, it supposed to be around 10-12 psi. Several A&P agreed and all pointed out to me that I must have a manifold leak somewhere in my system. It also translates to poorer engine performance because Light Speed firing timing depends mostly on MP and lesser degree on RPM etc.

Subsequently, I spent months again to chase down my "manifold leak". I tried the soap & bubble method (multiple times), starter fluid method, smoke methods, re-tightened all clamps with no success. Looked up the Cozy archives and Vans Aircraft forums. Found a few builders faced the same problem, yet no one was able to find their leak. I finally decided to continue with my Phase 1 testing and worry about my performance later on...

[Hind Sight] After I completed my Phase 1 testing program and collected many performance data (100 hours of flight time), I am not sure my low manifold pressure (at idle) is really that significant after all. Maybe some day I'll learn about it!

Oil Temperature Jitters        

Some time during my Phase 1 Test, my oil temperature reports jumps around a lot. My past experience has shown that my oil temperature has always been a bit low. Normally under 180^oF. Therefore, I was not too worried. Regardless, I have to spend some $ and effort to replace the oil temperature sensor. It was a pain to remove and safety wire it back again, especially after the engine is already mounted on the plane.

Fuel Pressure Drops

I believe I have sensor component fails more than any Cozy builders. Again, during my Phase 1 Testing (when the electric fuel pump is off) I get fuel pressure alerts (below 20 psi) from time to time. Flip on the electric fuel pump and all is well again. However, since my electric fuel pump is my backup system, it would be unwise to rely on it all the time. Time to replace the mechanical fuel pump. It was a pricey component, but the replacement effort was relatively simple (if you follow the directions carefully).

[Hind Sight] The new mechanical fuel pump worked well - above 25 psi consistently (100 hours so far).

Push Rod Replacement

I have no idea what a push rod looks like, let alone the functions of a push rod. During my months-long pursuit of manifold pressure leaks, it was suggested that an excessive long push rod MAY cause the exhaust and/or intake valves not close completely - resulting in high manifold pressure. Since I was replacing the gasket on my #3 intake pipes, Bill Ortel decided to inspect the length of my #3 push rods. Since I was going to replace the seals of my cylinder covers at the same time, it would be a good time to do so.

Upon removing the #3 push rod, it was found to be a bit too long. So I decided to check all push rod lengths. Fortunately, only #3 push rod was too long. The rest were OK. If you are ever in the unfortunate position to remove your push rod, I suggest you use a (squeezed tip) syringe to squirt some oil around the push rod shroud o-ring. That will make the removal of the shroud a much simpler task!

[Hind Sight] I am sure having all the push rods within Lycoming specifications is a good thing. Unfortunately, it did not change my slightly higher than normal manifold pressure issue.