Maintenance: Fuel boost pump leak.

The first flight following my second annual was a ~200 NM roundttrip to have a "$100 salad" with a friend.  The plane was returned to the hangar following an issue-free flight.  Upon going to the hangar four days later, when I opened my canopy, I was greeted with a strong odor of avgas.  Clearly, there would be no flying that day.

Knowing that the only part of the fuel system that was touched during the annual was around the filter (to remove, inspect and replace the latter), I immediately removed the F-01452 Aft Tunnel Cover to inspect the area.  Fuel stains were located around the airframe's lower F-14108A Fuel Pump Bracket yet not the upper F-14108B Fuel Pump Bracket (see below diagram from Figure 31-11, brackets in red). 

Here is an image following removal of the pump and filter.  You can see the fuel staining on the lower Fuel Pump Bracket.

There was no staining near or on the boost pump's output side (thus the output fuel line remained sealed to the pump).  Additionally, no fuel staining was noted at the joint between the filter and pump or anywhere on the filter body, confirming that the leak was not due to the filter as that seal remained intact too.  Fuel stains were concentrated at the joint between the pump's segments at the lower-most, fuel input side (the pump is segmented, composed of three parts).

So what happened?  It is my hypothesis that when the fuel filter was reinstalled and joined to the pump (using standard NPT torquing guidance of "thread with fingers until resistance then 1.5 turns more" - see Section 5.27), the seal failed at the segment described above (drawn as a blue arc in the top-most plan-view image).

It appears that this same leak has happened to at least two other people.  I neglected to take a picture of the staining on my pump, but the pictures below indicate the same area of leakage.  Both images are from the thread referred to previously.

Upon contacting Andair, they requested that I send the pump back to them in England for complementary repair.  When received, they reported to me that they pressurized the pump and could not find the leak and requested more information about the location of the leak.  The following day they reported that the leak was found (no information given on what was done differently the second time around).  They said that they "replaced the pump body with the latest iteration (now machined as one part instead of three) and also replaced the pumps (sic) inner rotors to the latest spec and a new ESC."  So this new-ish pump should not be subject to the same leakage problem as the original.  I don't know what advantages the new rotors or an "ESC" (electronic speed control?) give me.

Here are images of the new pump with the single machined body.  It appears to me to be composed of two pieces with the fittings attached via hex screws.  The joint where it leaked before remains on the new pump body.

The new pump makes the same noise as the old one however its wires are now Tefzel.

Maintenance: Second annual condition inspection.

The second annual was completed at 165 hours.  My inspection checklist can be found below and on my page with my POH, flight checklist and flight test cards.  Be sure to customize the checklist to your own aircraft, should you choose to use it.

Here is the aircraft with everything removed prior to the start of the inspection.

There were no findings of particular concern.   Here are the findings of interest:

Modification: Increasing roll servo leverage.

At high speeds, the control force on the ailerons is significant.  My GRT high-torque roll servo just can't articulate the aileron pushrods without slipping its clutch when flying at speeds above around 140 KIAS.  I had already moved the servo control arm closest to the servo arm pivot point, as shown below from GRT's autopilot installation manual.

With that option exhausted, I needed to increase the mechanical advantage to the roll servo.  Below is what my install looks like now, when the motor is overwhelmed by the control forces at high speed.  You can see the servo pushrod is at the "min throw/max torque" position.  And it's connected to the bellcrank one inch below the aileron pushrod pivot point (as accommodated by the bellcrank design).

Below is what I planned to do.  I wanted to make a new bracket (grey) that moved the attachment point of the servo pushrod (yellow) further from the bellcrank pivot point.  This would give the servo greater mechanical advantage (since large movements of the roll servo would translate to smaller movements of the aileron).

So, I hopped into LibreCAD to fashion some brackets with varying lengths.

• My plan was to make these brackets out of 0.125" 4130 steel stock.  I suspect  that's thicker than it needs considering the bellcrank material is much thinner.  
• The spacing between the aileron pushod rod end bearing and the nutplate on the bellcrank for the servo pushrod's original position is exactly 1". 
• I wanted to use a nutplate to attach the distal rod end bearing of the servo pushrod so I didn't have to fuss accessing a nut on the backside of the bracket in the limited space afforded by the inspection panel.
• The bracket width of 1.2" was dictated by the mil-spec edge distance requirements associated with nutplate rivets (I later found out that this was too thick and would bind on the aileron pushrod).

This would also mean I would have to lengthen the servo pushrod from 3.25" to 4".  So I bought some tubing and used this method to drill holes in the center (since I don't have a lathe or mill) and threaded it.

Here's my collection of brackets ready to go.  In retrospect, I gave myself too many length options.

Here's a bracket (second from the left above) attached.  The geometry of the pushrod didn't work out as the servo arm's angle exceed 30° of travel (causing a potential over-center instance and thus jamming the roll control).  No adjustment of pushrod lengths, across the four pushrods I had, would yield an acceptable geometry. 

I then made this temporary, not flight-worthy, bracket next.  The pushrod geometry with this bracket also did not yield something workable.

Next, I fashioned a new servo arm that has a hole slightly lower than the one on the stock arm.  Below is two of those exploratory, not flight-worthy, servo arms.  The large hole bolted to the servo.  The next hole goes to the shear screw.  The next hole(s) are locations for the pushrod.

As the pair of pictures below show, the servo arm with even "more torque, less throw" also did not have a workable geometry.

So at this point, I have no solution to the issue.  GRT has already checked out the servo.  They are checking with their software group to see what else they can do, yet I don't expect to hear back from them.  I remain of the sentiment that the servo lacks sufficient torque for the aircraft and that's the way it shall be.

Interior: Poor man's seat warmers

It's winter time.  It's cold.  And so are my buns.  So, I snagged some "cheap" heated seat pads that plug in to a USB port.

Of course, that won't work in an airplane with narrow seats and a crotch strap.  So I removed the heating pads and placed them on my plane's seat.  I only need them on for a few minutes, then I'm good to go.  I will probably make a fabric pocket to place them in.  The pads plug in to my console USB socket.

Update 21-Jul-20:  When I got my interior rounded out, I had little covers made for these heating elements.

Pitot-Static: Steam gauge altimeter calibration

I have a Winter 7 FMS 523 altimeter as a steam gauge backup on my panel.

The altimeter is consistently off by 200'.  It turns out that adjusting an altimeter is relatively easy:  There is a small screw near the main adjusting knob.  One simply backs this out and then you can pull the main knob out to change the altitude without changing the value in the Kollsman window.

Below shows that small screw on my altimeter.  It was packed in grease (probably to mitigate it from falling out) but easily accessed with a jeweler's screwdriver.

Avionics: New GRT and Garmin flight data logging analysis tool.

This page is deprecated.  Go here for the latest version:   

 

The most up-to-date version will always be found here

 

Do you have a GRT or Garmin EFIS?  I have a GRT and friends with Garmin.  These EFISs record a lot of data but we don't have good tools available to view those data, especially for GRT.  To that end, I have created a comprehensive and very simple to use Microsoft Excel-based flight data log display tool.  The most up-to-date version will always be found here (use the download icon in the upper right after clicking on the link).

• Version 3.1 released 3-May-20.
• Version 3.0 released 2-May-20.
• Version 2.1 released 3-Jan-20
• Fixed incorrect array index causing inflight and ground distance calculation errors. 
• Version 2.0 released 17-Dec-19.
• GRT "standard inputs" defined dynamically and identified on "Options" sheet. 
• Faster code.
• Added support for Garmin data logging.
• Automatically selects/deselects data for for GRT/Garmin.
• Added stack of GRT Aux and analog graphs to "Graphs" sheet.
• Version 1.1, released 17-Sep-19.
• Added option to extrude flight path to ground for better visibility. 
• Added option for to display full path to KMZ file after generation.
• Added EFIS bus voltage displays to Route data in KMZ file.
• Generalized CSV parsing to support future changes in GRT file format.
•  Version 1.0, released 15-Sep-19.

Please contact me if you find mistakes or if you have suggestions.

• More than 30 engine and flight parameters plotted.
• Each graph is one-click zoomable with user-defined zoom scales.
• Extrema of all parameters shown.
• Times on ground and in air calculated.
• Integrated UTC offset to set displayed times to local.
• Nearly all parameters have user-defined names and units.
• Complete instructions provided on spreadsheet, including how to setup your GRT EFIS to record flight data. 
• Plots all data or, to focus on a particular portion of a flight, only a specific time period.

• KMZ file, for integration into Google Earth, automatically generated.
• 53 selectable engine parameters and flight data shown at each point on the 3D map, including distance and time to next plotted point.
• All points can be plotted or
• Four optional user-selectable thresholds to control which points to plot.
• Plotting at user-defined epochs (e.g., every 30 seconds)
• Lines colored according to user-defined flight status parameters (ground, climb or descend)
• Aircraft registration, flight time and date integrated into route names to manage multiple saved flights in Google Earth.
• Airplane icon points in direction of magnetic heading.
• Click on any location to get selected flight and engine data.
• Each point labeled with the time using user's UTC offset.
• Google Earth lets you:
• Plot multiple flights.
• Animate your flight path.
• View flight paths in 3 dimensions from any angle.
• View engine and flight data specific to aircraft position. 
• Have far greater positional resolution than FR24 and FlightAware KML files, and includes flight and engine data.
• Plot against geo-referenced charts such as sectionals and TACs.
• These may not have current charts (original files from Chartgeek):
• Sectional kml file downloadable here (deprecated, see newest version).
• TAC kml file downloadable here (deprecated, see newest version).
• Instructions for manually importing charts into Google Earth are here (deprecated, see newest version).

Here is an example of overflying the field and executing a right 270 to join the downwind.  This is from an oblique angle.  In this plot, the user specified that the flight path should be marked red when the VSI is less than or equal to -500 ft/min.  White indicates ground operations.

This is an example of a flight where the user chose to have points plotted only when certain flight data have exceeded specified thresholds.  Furthermore, each point can be clicked on to show user-specified flight data.  Airplane icons point in the direction of magnetic heading.

This is an example of an entire flight with the icons turned off.  Green indicates the portions of the flight path where the VSI was specified by the user to be 500 ft/min or greater.   Red was specified by the user to be -500 ft/min or less.  White tracks indicate ground operations.

You can even plot your flight path and data against FAA charts in Google Earth.  See above to learn how to do this.

An example of a zoomed-in CHT graph.

The tool is completely automated:  One button to import data, one button to create a Google Earth KMZ map file.  It's generally fast to import (about 5 seconds on a modern computer) and speedy to create the KMZ file (2 seconds), though older computers will need more time.

It has been tested on a PC with Windows 7 and 10 with Excel 2007, 2010 and 365.  It assumes your EFIS provides GRT's version 2 flight data logging.  It also assumes you have a single engine.

Maintenance: Starter failure #2. Replaced with different model: 149-NL.

My factory original SkyTec 149-12LS starter failed at 43 hours.  It suffered from the well-known sticking of the solenoid.  The replacement starter failed with the same issue at 103.9 hours.  Not wanting to see a third instance of this issue, I asked SkyTec (now Hartzell) if they would replace my 149-12LS with a 149-NL, which they did.

The 149-12LS has an adjacent solenoid, is 8.25 pounds and uses a permanent magnet motor with a 3.7:1 reduction gear.  It has a strontium-fortified 356 T6 aluminum alloy mount, needle bearing in nose, brass bushing in rear.  160-180 RPM at 11 V, 185-285 A.

The 149-NL has an inline solenoid, is 9.3 pounds with a series wound coil and 6.5:1 reduction gear.  It has a field-replaceable shear pin for kickback protection, die cast A-380 aluminum mount and 3X steel ball bearing races.  ~120 RPM at 11 V with 85-125 A. 

 

 

Here are the two original, failed 149-12LS starters.  When they were both removed they each had ejection of packing grease which the Hartzell technician assured me was normal.  Original 43 hour 149-12LS starter on left (from 20-May-18) and replacement 103.9 hour 149-12LS starter on right.

Now on to the third starter...There are four bosses on the 149-NL starter.  Boss A is for the V-1002 alternator-to-starter link (see plans page 43-12).  For the IO-390, bosses B, C and D can be removed, per Hartzell's instructions, to within 1/8" of the casing (see ST25001 Rev. J).  I did that with a cutting wheel on a Dremel then smoothed things down with a light grinding wheel (bottom left and right images).  Boss D doesn't have to be removed for use in the RV-14A, but might as well trim off the ounce of weight.

The 149-NL starter fits fine on the IO-390.  However, in the RV-14, the mixture bracket assembly (see page 50-03 and OP-22) has a F3414M Rod End Bearing that binds against the starter casing.

To alleviate this issue, I moved the Rod End Bearing to the outboard side of the Mixture Arm (it was easier than changing the clocking of the arm then making gross changes in the cable length).  Some changes in the washer stack and readjustment of the mixture cable travel was necessary to ensure full Mixture Arm travel and compliance with the "vital criteria" on page 50-02 (stoppage is achieved by the control stop, leaving a 1/16" cushion gap).

The next unknown was if the cable going to the starter would be long enough for the 149-NL (the 149-12LS has its terminal about an inch further aft).   

Turns out that the original WH-P16 Starter Relay to Starter Wire has its spade connector bent in page 43-11, Step 2 (visible above).  Upon bending this back and taking up some of the slack in the cable, it reaches the new starter just fine.

 
The next issue was the Van's wiring approach.  Van's has the "I" terminal of the starter contactor on the firewall connected to the 149-12LS starter with the K910 Starter Disengage wire (see page 43-04), shown as the little hanging wire above.  They do that to eliminate "hesitation in disengaging from the ring gear" (the LS has an internal contactor).  There is no provision on the 149-NL starter for that approach since the starter's "S" terminal has been "repurposed" for use as selecting either 12 or 24 Volt operation through the use of a jumper.  Thus, one can remove the Starter Disengage wire with the 149-NL.  But, this would leave the "I" terminal on the firewall starter contactor exposed (ES 24021 on page 43-04).  So I just cut the wire at the spade lug and used a wire-tie to affix the nipple in place.  Below are views of the starter contactor showing that nipple on the "I" terminal from above (left) and below (right).

The 149-NL starter gear sits in the same place as the 149-12LS' when retracted.

The next unknown was if the VA-132-2 Snorkel fitment would be impeded by the new starter.  Thankfully, there was more than enough clearance.

The 149-NL starter has more torque than the 149-12LS and it sounds more stout.  Hopefully the 149-NL is of higher quality too.