Flying the Sling 4!

Wanted to give a quick update.  Visited with Matt and Jean at TAF on December 6th.  I planned to take a lot more pictures and videos...but:

Once we got in the airplane, Matt  pulled up the electronic checklist, and let me do everything from engine start, to taxi, run up, takeoff, and we flew for a good 45 mins. 

I did three landings - two were touch and goes, one was to a full stop on the short runway (29L).  

With two of us aboard, OAT was around 60F, at 115% power and the electronic prop control on T/O we climbed initially at 80 knots around 1200 FPM.  The sight picture isn't good at that pitch, so we nosed over for better sight over the front, at 90-95 knots, and we reached the pattern altitude before even turning to the downwind leg after takeoff for the departure to the west.  

We went out over the edge of the Pacific Ocean and flew down to Long Beach harbor - I did a few steep turns.  Then we slowed back down, hung out full flaps and did a power off stall.  It buffeted a little and dropped the left wing at 50 knots...The recovery was easy, it didn't have any adverse Yaw or reaction to stall recovery.  Simply drop the nose and it starts flying. Add power and start climbing again.  

Full power (100%) without the engine in the extra boost phase used for takeoff, we leveled out at 4000' and cruised at 126 knots IAS.  TAS was 135Knots.  You change the prop control to climb after you leave the pattern and it reduced RPM to 5500.  We dialed the control back to cruise and the RPM came back to 5200 +/- and the fuel burn reduced to around 5 gph.  

It's a very quiet engine/ airframe, reminded me of a turbo prop, or a video game. Very little engine vibration, climbs very well with just two aboard, and has distinct handling (no slop).  

Landing was Similar to the Sonex, but it's hard to slow the airframe down.  Flap extension speed is 85 knots.  It takes full flaps to get it dirty enough to descend without gaining airspeed.   I greased 2 of the 3 landings.  The first one Matt had me come in pretty high over an oil refinery that's on final, and then I slipped it down about 800', on short final.  The rudder has a lot of authority and reacts quickly when you bring it back around.  The toe brakes that they have as an option worked very well in conjunction with the direct nose wheel steering.

Did get a few pics after we landed!

Elevator Tips

1.5 hrs - this post is about completing the ends of the elevator- not about hints (tips) for building the elevator!  The directions are fairly simple and clear for this step.  Wrap the tip rib (with attached counterweight) with the forward elevator tip skin.  Cleco and rivet.  Then insert the fiberglass composite tip, position inside the aluminum skin, then drill and cleco the tip in place.  Once it's fitted then clean up the holes as needed, insert the rivets and complete the assembly (pull the rivets).  The fit was pretty good, looks like the trailing edge of each tip will need to be faired/filled to match the profile of the elevator aluminum skin better.

Elevator Skin (Left side)

2.5 hrs. - Today Liam and I worked on the left elevator Skin, which is more complex than the right.  Made sure we inserted all of the doublers for the rear channel that supports the trim tab.  Everything fit together pretty well.  The last items to do on the elevator is the outer forward skin and the composite tips.

Elevator Skin (right side)

2 hrs. - Removed the right skin fm the shipping crate, pealed off the inside film and cut away the rivet hole lines...and primed the inside.  Carefully attached the skin to the right elevator structure and only had to open up a few holes on the top of the #1 ri to avoid the trailing edge deformation as shown in the plans.  Once both sides were clecoed - I began riveting!

After finishing both sides - I then clecoed and riveted the leading edge where it wraps over the top and bottom skin.  I had contemplated dimpling this rivet line and using CCC-42 (flush rivets)...but decided to just do as the plans call for.  Once finished I trail fit the elevator to the horizontal Stabilizer...and it fits!

Happy Thanksgiving! Elevator assembly continues...

2 hrs.  Continued installing and riveting the ribs #2 and #3.  Unfortunately I mixed up the location of the Left and Right sides since I was building this upside down (to allow for the elevator control horn to face up).  Had to drill out about 12 of the larger alum. rivets...move the ribs to the opposite side, and re-rivet.

Moving on to the outer Ribs, now it gets a little more fun.  Had to cleco and then updrill the counterweight to allow for the extra large 4.8mm rivet to fit.  These are rivets on and I'm going to only do one side at a time for the outer rib, and skin since my work table is only 6' long.  I'm finding the counterweight is torquing the last rib and entire elevator structure if it's not supported.

Elevator parts prep and begin riveting spar

3 hrs. - I've consolidated a few separate sessions into this post.  Began by prepping the elevator spar, ribs, attach angles, doubler channels, etc. by removing the plastic film, and deburring edges and holes as needed.  Primed all of the parts with self etching primer.

After the primer set it was onto following the steps in the book for item #1 and #2.

And a detailed picture of the elevator control horn and center hinge bracket with the inner ribs (rib 1 -  left and right) now attached with rivets and the AN-bolts/nuts.

Elevator Trim Tab

1 hr. - Assembled the elevator trim tab per the plans.  The instructions are a bit confusing as they indicate the need to modify the rivets (for the whole assembly?) due to them being too long.  We only found the first to rivets on the control horn tab needed shortening.  All of the others were fine.