Modifications to Tail Wheel

August 3, 2023

Note: My tail wheel, spring, and attachment to the tail cone are of my own specification and are NOT as per the manual.  Design parameters are intended to make field repair or replacement easier if away from home base.  My drawings will be attached for clarity.

 As result of my taxi testing and test flight I have decided to change my tailwheel configuration.   There are a few things that I want to improve, 1- the tail sits to low causing poor forward visibility and I would like to raise it,  2- My original spring (single trailer leaf) was too short, 3- I didn't like the alignment of the tailwheel  steering link and chains to the rudder pivot, 4- I can  afford to add a bit of weight to the tail as my test flight indicated a bit nose heavy and would not allow hands off trim for level flight (single pilot and 3/4 fuel).  I will experiment with carrying some weight in the baggage compartment on next flight.

Overview:  A rectangular steel tube was made in a bent leg shape to attach to the bottom of tail, a flox bed was formed to mate the metal leg to the tail.  A trailer leaf spring (new) 1.75x5/16 thick is disassembled so one, two or three leafs can be used as the spring.  A Matco tailwheel  is bolted to the trailing end of the leaf spring.  The new tail spring leaf is 9.25 inches longer than the original I built.

Second test flight attempt cut short

 June 26 2023

I attempted a second test flight but on climb out I was getting a popping and occasional backfiring from the engine.  My flight with one other Vans RV9 was cut short and I only completed one large circuit before landing as soon as possible.  My landing this time was much better but because I took my eye off of the centerline to look at my airspeed I began to turn and ended up doing a ground loop on the runway surface, thankfully no damage was incurred.  I have learned I need to make centerline and the flare the only things I do until slowed right down.

The popping noise was eventually identified as two of my lower spark plugs had lead balls on each which shorted them out and were not firing.  The excess fuel then exploded at times in the exhaust pipe.  I have bought a second set of plugs so I can have a clean set ready to begin any further test flights.  Being a newly overhauled engine it is also letting oil past the rings and into the spark plugs.  This is a real pain because I need to fly the engine hard for awhile to get the rings to seat properly.  Working on these small problems require more ground running to confirm problems have been rectified.  Oh well such is flight testing.

Rebuilt magnetos installed

 May 30 2023

What a lousy spring we had here,  I did not get out to begin working on the plane this year until the middle of May.

I removed my magnetos and via a local shop had them sent out to be professionally rebuilt.  As I get into flight testing there are a number of concerns that I have with engine equipment.  The engine was rebuilt but I never had any documentation on the magnetos so decided it was best to have them looked at.  A very good thing as both needed seals, bearings, condensers and one needed a new internal nylon gear.  Very happy that I did this , I am trying to reduce some of the sources of potential engine performance problems before they happen.

Install of a backup Airspeed Indicator and Installation of One way Fuel tank Air vent valves at wing tips.

 March 22 2023

Addition of the backup airspeed indicator is  installed in the panel.  Reasoning for this is in case of the very rare possibility of the main screen going dark.  The glass panel screen has a backup battery which will keep the screen on for 1 hour should ship power be lost.  The backup airspeed indicator would give me airspeed should my main screen be lost during flight.  Landing approach speeds would be readable for a safe landing.

Addition of the One Way fuel tank air vent photo into the wing tips(left side is the same). Below is the right wing tip with the fiberglass  tip sitting on top of the wing.  The blue colored one way air vent is to allow the air to pass freely into the fuel tank but if fuel were to slosh out as far as the vent tube the one way valve will stop it going overboard.  The fuel tank interior has many ribs and anti slosh hinges installed inside the tank minimizing the sloshing of fuel.  The blue foam on the one way valve is now wrapped completely around the valve so there cannot be any metal contact to electrical connections in the wing tip.

Modification to Elevator - Adding additional counterbalance lead -

 January 11, 2023

My elevator was static balanced during construction along the hinge line.  Once installed I found them to be tail heavy when all drive tubes were connected.  I  left the lead weight space accesible (removable foam + rib) in case I needed to add additional lead, just behind the original forward lead installed.  A additional 2 pound of formed lead was added to each elevator tip and elevators are balanced up perfectly.  The lead was floxed into place and a 1/4" rib was installed (floxed) along the aft edge of the new lead.

Two layer of bid fiberglass is to be installed to cover the foam.

First Flight (Initial Test Results)

 August 31 2022

Some findings after my first flight.  

The airplane flew well and the engine performed very well.  There were some minor issues that presented and will have to be addressed prior to a subsequent flight.

1. After 2 hours of flight slowly decreasing oil pressure presented but cylinder temperatures remained in the green as did the oil temperature.

 Details:  The belly of the airplane was covered in oil which had escaped from the oil separator can overboard exit point.  Three and a half quarts of oil was lost in 2 hours of flight.  This appears to have been because I have the exit tube hanging below the lower engine cowling by 3 inches.  This resulted in  sucking oil out of the low drain back return tube from the engine case.  I have changed the oil exit tube to be only 3/4 inch below the belly skin which is still 2 inches above the lower engine cowling rear lip.    This might have compounded the negative pressure in the tube because it was hanging to low.  I have taken the oil separator completely out of the vent line circuit for now in case it was causing some sort of venturi effect within it's interior.  Now the vent line rises 2" as it exits the engine and drops down to the exit point 3/4 inch below the belly skin. 

2. Bad landing with low left wing caused bending of the pitot tube as it touched the pavement on exiting runway.

 Details:  The pitot tube was bent back into shape and it tested working fine.  A bit of liquid metal was used to cover up the scrape marks and was then filed smooth and surface painted.  The under side of the wing was damaged at this location and the pitot tube mounting nuts had to be lined up and re-bonded.  The skin was punched in a bit and was repaired and resurfaced smooth.

3. Rudder pedal vertical tubes need reinforcing with gussets.

Details:  During my landing and exiting of the runway into the grass my tail wheel went into full swivel turning me left.  I hammered on the right rudder pedal trying to arrest the left turn and partially broke the right rudder pedal.  This again was my mistake as my only steering option at this point would have been to use right brake to arrest the turning.  I have since seen a Service Letter that VANS aircraft had issued to it's owners to re-enforce the rudder pedal vertical tubes with a gusset.  This I have done, as I believe it is a good safety upgrade.

4. Aircraft is flying in a slightly nose heavy attitude with full nose up trim set.  During the test flight I had to hold very slight back pressure on the stick throughout the flight. 

Details:  I am going to add more weight to the elevator counterweight because I found it to be under balanced after installation.  I am also modifying my tailspring by making it longer and with a little more bend.  This will add a bit of weight to the tail and raise the tail for a bit better forward visibility.  If more weight should be needed I have designed it so I can can bolt a piece of lead directly onto the tailspring.

First Test Flight

 August 10 2022

Today was the big day for getting the first flight completed.  The object of the flight today is to break in the Lycoming engine as per the Lycoming recommendation for a totally rebuilt engine which was not run in at a shop after rebuild.  The run in of the engine is supposed to be 2 hours of flight at 2450 rpm and leaned properly for the conditions.  During the second hour the rpm's can be varied from 2350 through to 2550 for seating of the rings to the cylinder walls.  Of course this was only if the airframe would fly as expected.  Weather conditions were just perfect with clear skies and no wind.  At 10:00 in the morning I was airborne and completed racetrack pattern flights 1.0 miles (minimum) from the active runway at my local airport.  Temperature was 20 C and flight altitude was at 6500 feet.  

Here is some additional information for those that are building this "Vision" experimental aircraft.  My engine is very similar to the Lycoming O-320 but is a 1960's variant, Lycoming O-340 build by Lycoming specifically for the Navion twin aircraft. (They only manufactured this engine for about 8 years and was replaced by the O-360).   My engine is a totally rebuilt engine with zero time on it.   It has slightly higher compression and cylinder size than the 0-320 and is rated 140 HP.  The engine performed very well and was showing an indicated airspeed of 158 knots.  Compensating for temperature and altitude on this day the true airspeed was 180 knots.  This is right where I was hoping to see  my speeds.

One of my friends agreed to be my safety person to watch over me in case of issues where my wife might have to be notified, thankfully there was no need.  The flight lasted 2.2 hours and was recorded by my Mode S Dynon transponder to FlightAware.  During the complete time of my test flight I was under the surveillance of Calgary Class C airspace radar persons.  The flight went quite well but my landings were very bad, the first a 2 bounce go around the second a 2 bounce go around and the third a 1 bounce that  sent me 45 degrees off runway stopping in the grass.  After 6 years flying my Quickie Q2 I had some ingrained landing habits I needed to get rid of.  In short this was the tendency to keep pulling back on the stick in landing to pin the tailwheel of the Quickie.  This aircraft requires a flatter approach in ground effect to lessen any tendency to cause the airframe to balloon me back up after touchdown.  More details will be given in a upcoming post.