flying instead of building

Well, didn't get out to the shop to do any building because I went flying instead.  I don't want to let my flying skills deteriorate due to spending all my free time building the new plane.  I was getting close to loosing my currency for IFR flights, so yesterday Ed & I took the Cirrus up for a good workout.

The weather was perfect for an IFR training flight.  There was a nice big low pressure system (29.69 inHg) sitting over Ohio yesterday and that gave us a cloud layer from about 1000' to 4000' above the ground.  I flew and Ed observed/coached/critiqued from the right seat.  I flew to Dayton, did a hold and shot the RNAV 24L approach there, all using the autopilot.  In other words, I programmed & observed while the plane flew itself.   That's the Standard Operating Procedure for an actual mission.   Then I disconnected the autopilot but left the flight director engaged and flew the same approach by hand.  The flight director essentially is a display driven by the autopilot that says, "if I still had control, this is what I would do."  Basically, it's a video game -- the A/P moves the cueing display and I fly the airplane to match the cue.  Then I turned off the flight director and flew using just the displayed location data.  I flew all the way back to Delaware by hand, went to the far side of the airport to get aligned with the wind and few the RNAV 28 approach back home.

Overall, 2 hours of a good workout and I feel better about being a competent pilot.

Back to building when I get home tomorrow.

§26 Left -- Rear Spar to Tank

Well, I took a deep breath yesterday and committed to joining the rear spar to the tank.  The section is a whopping 2 pages of actual instructions -- 1 page says to cleco everything together, the other says to rivet it.  All 33 rivets are 470AD4-4 that needed to be bucked since there was no way to get a squeezer anywhere near both sides.  

I am still quite leary of my skills in bucking rivets, hence the trepidation in this step.   Having said that, I'm actually quite pleased with how it turned out.   I am starting to get the feel of how much force to use with the bucking bar.  Counterintuitively, holding it with too much pressure simply causes a lot of noise and not much deformation of the rivet tail.  Obviously, not enough pressure and it simply bounces away.  If you use just the right amount of pressure, the tail of the rivet sets in only 8-10 impacts.

Some of the rivets were in a place that I could only see the shop head and had to hold the bucking bar blindly.   I'm quite surprised that it went well.  I did use the guage to ensure that the shop heads were within spec. 

Tomorrow, I'll finish riveting the spar, tank and inboard mixer box together.  Those use the famous Cherry rivets that are stronger than the regular LP3-4's but are harder to pull correctly.   The sealant should arrive tomorrow or Wednesday and I'll re-seal the Left tank.  They say 3rd time's the charm.  Stay tuned.

§28-14, -16 L&R Aileron bellcranks

 Two steps forward, one step back.    The right tank now holds pressure.  Sort of.   The left tank still has a definite leak at the fuel sender.  I used a cartridge of sealant from Aircraft Spruce, but the gun I bought (that morning) from Home Depot is much too large for the cartridge so I ended up just shoving the base with a spark plug socket as a make-shift plunger.  That made it barely possible to squeeze out the bead of sealant, with the resulting poor performance.   Since then, i've borrowed an appropriate sized gun and will give it another try when the next cartridge arrives from Aircraft Spruce.

I've been holding off attaching the spars to the tanks until they were sealed, but I'm going to go ahead and resume major construction since the leaks are at the other side and can be dealt with in parallel.

I built up the aileron bell cranks.  Took just a day and was a nice, straightforward project.

underexposed picture of the bellcranks

The aileron push rods have specific instructions to be primed.  I learned that just putting them on butcher paper and spraying them with primer, then leaving them overnight to get wet, results in paper that is well glued to the aluminum.  I sanded much of it off, but not all.   I stood the push rods using wooden dowels in the ground and sprayed them again while vertical.   I now have nice camo'ed push rods!

Aileron pushrods drying in the sun

 

§22-19 thru -26 Left

 Well, it's been a minute since I last posted anything here.  In addition to the usual 4-letter word ("work") that always is in the way, I had two very pleasant reasons to take a break from building.  

My eldest daughter came up from Louisiana with her family to visit for a few days.   Here are her 3 daughters and my middle daughter's son & daughter for a total of 5 grandkids.   It was a great, but short, visit.

One of the reasons it was a little short was that her visit overlapped with Thunder Over Michigan, an airshow held just west of Detroit.  My wife recently announced that she wanted to have a helicopter ride, preferably in a UH-1 "Huey", and of the attractions of the show was such a Huey.  Christie went to go stay w/ her sister and we drove up to Michigan and we got the ride she had hoped for!

Finally, back to building!  During the week, I received the extra parts from Van's that I had lost somewhere in the garage.  I finished building up the L outboard aileron attach bracket and got it riveted to the rear spar.  This completes the Left Rear Spar subassembly.   Recall that I had already built up the R outboard aileron attach bracket because of the mislabelled KAI. I thought I might as well build up the R inboard bracket since the workflow was already set up.  I then found the missing ouboard bracket cleverly imitating one of hte pieces needed for the inboard bracket.  This means that I'm missing that piece instead of the one that I just purchased from Van's.   "One step forward, one step back."   Sigh.

Next project:  Clean, scuff and re-seal the tanks.  I bought a larger batch (3 oz) of Fuel Tank Sealant than I typically use, but it's a 2 hr cure time instead of 0.5 hr, and it was actually cheaper than the 1 oz stuff from Van's.   I'll let you know how it worked in the next posting.

Left outboard aileron attach bracket assembly

Removed Fuel Senders

 I can't sleep and it's too late to do anything else, so I'm updating the blog.

My daughter & her family are visiting, plus I'm still working, plus we're going to try to go the Thunder over Michigan airshow tomorrow so I haven't had much time to work on the plane.   I happened to have 30 min to myself before going to work yesterday so I pulled off the leaking fuel level senders from both tanks.

Mounting location of removed R fuel level sender

As you can see, this doesn't look very uniform.   From 10:00 to 14:30, the darker and somewhat smooth color is fuel tank sealant that never even touched the base of the sender.   No wonder it leaked!  The lighter area is where there was some adhesion to the two pieces of metal and I had cut through it. Next session, I will clean that all off down to bare metal before trying again.

Curiously, there was no adhesion to the brass colored metal of either fuel sender.   I will really scuff up those surfaces, too.

Of course, to clean the inside of the tank and remove the debris from this process meant that I had to remove the inboard fuel tank access panels, too.  Those had been sealed with fresh fuel tank sealant and the showed proper, evenly 'wetted' distribution of the sealant after I got them cut off.  That made me feel better that I can apply things evenly if I'm using fresh sealant.

Both tanks, with senders and access plates removed. 

Good night.

§25 -- inboard mixer boxes

Section 25 is the inboard mixer boxes.  These were almost as easy as the outboard ones, but there are a few differences; mostly just a few more parts.  That made it a bit more complicated to ensure that I had the correct orientation when I built the other side, as I have a somewhat difficult time with L/R spatial orientations.

One trick published in VAF was to mirror the PDF images from the KAI in software.  Several VAF members have gone so far as to print mirrored pages of the whole book, but that's overkill.  I did something that was fast & cheap and just took quick pictures w/ my phone of the relevant pages.   10 seconds of editing on each page to mirror each one and I was in business.  Having just built the left version, I didn't need to refer to the printed notes very much and I concentrated on the object I was holding and comparing it to the image on my phone.  In the future, I'll use my iPad instead because of the larger screen and its attached stand.

Remember the NAS1097 rivets I talked about the other day?  I said that there were only 4 in the whole kit.   Wrong.  There were only four of the AD3-4 and I totally overlooked the bin that held 36 of the AD3-3.5's.  Those were the size I was supposed to use earlier.  As a result, when today's kit called out for the 3-4's I had none.  I elected to use AN426AD3-4's to achieve the proper length and deal with the larger head by accepting the larger countersink needed to flush the larger head than the called out AN1097.  The primary advantage to the 1097 is the ability to be used in very thin material, but the piece that accepted the rivets in question is quiet thick-- 0.063", so I ended up with something stronger (not needed) and the correct length.

Inboard Mixer Boxes

BTW, I'm determined to provide my grandson an early introduction to the project.  He just turned 8 and has a very short attention span, but I did manage to show him 5 different rivet setting techniques before he timed out.  Baby steps! :)     I have 3 granddaughters visiting later this week.  One or two of them may be interested, too!

Layne, learning about squeezing rivets

§24 Left

Like building the outboard mixer box itself, installing it into the rear spar was relatively straightforward.  It involved being very careful about which rivets were installed into which holes, since the structures had multiple pieces of varying thicknesses.  There were a lot of rivets that had to be driven, including some where it is really difficult to get your hand in place with the bucking bar!  I'm very glad I spent the money on the tungsten bar -- its small size came in handy for just this occasion.   I suspect I will never need another bar that doesn't have a unique shape/size.  (There are bucking bars for sale specifically for doing some hard to reach rivets in the tail cone of the RV-14.)

I took a picture, but it's not worth publishing because it looks just like the last one of the rear spar & ribs.