Saturday, January 6, 2018

Left fuel tank back on wing and stall warning.

After testing the left fuel tank, it was time to put it back on the wing.  But before this, I wrestled with the decision of whether to install the stall warning horn.  I had previously put rivets in the holes that define the stall warning vane opening.   I'm going to have a heated pitot tube with AOA but I decided to install it anyway for the following reasons:

  • I have always flown airplanes with standard stall horn - it's "wired in"
  • I like redundancy
  • It will work correctly on first flight, unlike AOA which needs calibration
  • I can wire it to a light or an audio tone as opposed to a "Horn" which may not be easily heard with ANR headsets
  • I can always disconnect it, but it would be hard to add after finishing the build 
  • I already had the parts
I had to remove and replace because the initial position didn't allow the microswitch to trip properly - easy fix.

Tank is back on wing, easy peasy.

Friday, January 5, 2018

Fuel tank tested (left wing), and the power of VAF

I'm trying to do more frequent updates as I have in the past.  Not much happened since last post but I did test the fuel tank - 3 times.  After installing the fuel sender, pickup/strainer, and fuel strainer (bottom of tank) - I removed the fuel strainer, put an air valve (Schrader valve) in place, put a balloon on the vent opening, and filled the balloon with air.   Each time I went over every seam, rivet, etc with soapy water in a spray bottle, looking for leaks.  None found.  I was worried because the balloon didn't hold air indefinitely.   So I called Vans and spoke with Gus who said this shouldn't be a concern - it's hard to seal the balloon completely, and if the soapy water test finds nothing it's unlikely that there will be any leaks.  I may repeat the test after replacing the tank on the wing.

I got a fantastic message on Vans Air Force 2 days ago - someone who follows this blog noticed that I had made a mistake installing two (symmetrical but different) parts on my fuselage.  These parts (F-141119 root fairing attach angles) were installed "backward" - actually on opposite sides of where they should be.  So I ordered parts to replace/fix this error.  Here's what's great about this:

  • Folks are following my blog (great as long as no one thinks of me as a source of "correct" knowledge about building an airplane)
  • They care enough to point out mistakes when they see them (please let me know if you see a mistake!)
  • I can easily fix this now - it would be hard if I discovered the error when trying to put root fairings on when wings have been mounted
  • VAF continues to be a community where folks help each other out.
Another point:  I sometimes get a bit sloppy in keeping track of which part is "left" and which is "right" - sometimes (like in this case) this matters.  Frequently I use a Sharpie to mark parts but the problem is that when I clean the part with MEK/alcohol to prep for priming, the markings get removed.   I've found in past cases that I can usually look at plans, or use rivet pattern or other distinguishing features to figure it out - in this case that all failed.    I recently used my spring-loaded center punch to put unique patterns of "dots" on parts to match up after priming.  This may be a good method going forward (1 dot right, 2 left or something like that).   Here's an example on an aileron pushrod ("two dots" match up both part and hole pattern)

Wednesday, January 3, 2018

Left wing - aileron and flap gap seals riveted.

Quick update - see photos.   Also will start testing fuel tank today - received balloons from Amazon and sealant on the fuel sender has cured.

Monday, January 1, 2018

End of 2017 Update - starting on QB wings

Since the last update I received QB wings and have started work on the left wing.

Before starting wings I wrapped up the vents.  Not a big job but I made one decision (after checking with Van's) to make a small change - I decided to rivet the vent brackets in addition to using silicone adhesive.  I match drilled two holes in each bracket and then dimpled them: easy on the brackets but on the fuse side skin I had to use special dimple dies that pull a nail through to set the dimple.  

On to QB Wings:  First, I've inspected as much of the wing as possible, comparing the plans to what I see and checking work.  For the most part, work is very good.  I've found some rivets on the left fuel tank at the inboard rib to skin joint that I'm not impressed with, but I'm worried about replacing those since this area is sealed.  Will discuss with Vic Syracuse - if he says to replace these I will, using sealant obviously.

One of the first actual construction things I did was pages 17-04 and 17-05.  I installed the access hatch doubler (after the obligatory deburr, scuff, prime, dimple, using nutplates etc.   Looks very nice.   I also installed the landing light brackets - before doing this I primed inside the rib bay where the landing lights will be with black primer.   I countersunk and placed rivets in the two holes that are normally used to install the stall warning horn: I will be using AOA as part of my pitot tube setup so won't need the duplicate stall warning.

Next I fabricated the landing light lens and backing plates.  Fit is good but with a small gap at the leading edge - despite lots of effort to pull this flush during match-drilling.  I'll live with it and seal later after permanent installation of the landing lights.

I removed the left fuel tank after fabricating plywood forms and installing these on bench - will stay off wing until work is complete.

Last few days I worked on aileron actuation - fabricated the pushrods, installed aileron bellcrank, and fabricated the torque tube assemblies for both wings.  I'll hold off a bit on installing all this until fuel tank is back on wing and after installing the wiring/tubing in wing.

Today I bent the wire for the fuel sender float - after quite a bit of tweaking I'm happy with the fit and I went ahead and installed the sender, after testing resistance range. I used an "endoscopic" camera that connects via wifi to my ipad to inspect the positioning of the float and assure no interference with rib or vent line.  I verified electrical connection to airframe after installation - one of the screws that is used on the sender has a lock washer to ensure electrical connection.  Also installed plug in upper hole, fuel strainer/drain, and fuel pickup/strainer.

Saturday, November 25, 2017

November 2017 Update - Section 35 complete

Not as much done since last update as I would like, but I've completed section 35.  One source of delay was self-induced:  I didn't like the way match-drilled holes on the upper forward skin turned out so I replaced the skin, with all the expected issues that come with that - shipping time, skin edge prep, deburring, dimpling, priming, etc.

It turned out great and I finally have completed all riveting of the upper forward skin, attachment of the canopy hinge mechanism and mechanism for canopy release.

Next I'll wrap up end of section 29 (vents) and move on to QB wings which are sitting in the garage ready to go...

Monday, October 16, 2017

October 16th Update - Upper FWD Fuselage

Since the last update I have made substantial progress in section 35 - upper forward fuselage.  Much of this time was spent doing the usual prep of parts.   In the last few days I have completed the subpanel and am now working on preparation for riveting the upper forward skin.   I've also fabricated the pushrods for the canopy eject mechanism.  I don't plan to install the full mechanism but I will have the structure in place should I (or a future owner) decide to install the final part in the panel.  I also think having the structure there will make it easier in the future to remove the canopy for maintenance.

Monday, September 18, 2017

September 16th update - brakes and rudder pedals

Completed installation of brakes/rudders with Berenger master cylinders and TS Flightlines brake lines in fuselage, including installation of the brake fluid reservoir.

Looks really nice!