Sunday, March 27, 2016

Continuing work on the fuselage

Received a shipment of a few replacement parts so I finished off a few items that had been sitting partially complete for a while.  Next step was to rivet on the floor of the front fuselage.  It took a little while to sort out what holes in the side channels should and should not be riveted - once I figured out that one line of rivets was for the floor and one line of the rivets was for the interior side panel, it all made sense.  I also just about forgot the junction stiffeners, but managed to get them installed without issue. Also riveted on the lower firewall channels and the rudder pedals at this time - though I held off on installing the rudder cables for now.

Riveting the rear seat base
 
Riveted parachute box.  This is the updated box that is designed to sit about
 a foot forward of the initial location -  the move is to improve the
center of gravity when the rear seat was being  used.

Riveting the forward fuselage floor, rudder pedal base and lower firewall bracket

Rudder pedal bushings and clamps riveted in place
Not really clear, but the photo shows two lines of rivets in the floor of the front fuselage.
 The red line (with the installed rivets) is for attaching the floor to the floor channels.
The blue line, without any rivets, is for attaching the interior skin at a later stage.
After that, it was a deep dive into the fuselage center console and all the associated  forward and center fuselage covers.  Installation of many, many rivnuts was required for all the cover panels.  The rivnuts are used so that the covers can be removed during annual inspections, maintenance, etc. It became clear quite quickly that high quality hex keys will be very helpful.  I also riveted the slider on the front seat rail.  My sliders were a couple mm too long, so the ends were trimmed so they would lie flat on the aluminum angle.  The slider uses flush rivets to enable the seat to slide smoothly over its surface - it was easy to countersink the slider with a deburring tool. Since I had the seats complete, and since I was test-fitting the seat rails anyway, I figured I might as well go ahead and throw the seats on to see how it looked.  Was tempted to hop up on the bench into the seats and make airplane sounds!

Forward fuselage with center console and floor panels attached using buttonhole screws.

Rear seat foot well, with some panels  attached using buttonhole screws,
and some panels clecoed for future riveting.

Back panel of rear foot well riveted in place.  The floor panel will be riveted at a later time.
Components of the rear control cover riveted together.
These panels will be secured in place using buttonhole screws and rivnuts.

Support channels for the rear foot well still need to be riveted in place (on the underside of the floor).
Note that the location of these channels is not called out in the instructions, but it is a pretty obvious fit.

Front seat rails - remaining rivets will attach the rails in the final location.

Trying out the seat fit - pilot and co-pilot up front, and a bench seat in the rear for 2 more passengers.
The seats will eventually have leather upholstery (and perhaps an electric seat warmer as well).

The rear and front/center fuselage had been sitting a couple feet away form each other for some time so I decided to push them together and try out a test fit.  It became clear quite quickly that the longerons and rear seat ribs were not going to line up.  After scratching my head about it for a while, I emailed TAF and we determined that the orientation of the rear fuselage short longerons (RF-LGN-902) in the instructions (2014/02/19 revision) was incorrect and they needed to have their locations swapped.  So  the rivets holding the longerons were drilled out and the longerons were swapped and re-riveted.  This fixed the alignment issue and enabled the fuselage halves to be pushed together.  I also took the opportunity to add the forward skins and clecoed all the forward skin channels and the firewall to ensure everything else fit properly.

Oh-Oh!  No way these longerons are going to fit between the rear seat ribs. Turns out the
image in the instructions (2014/02/19 revision) is incorrect and the short longerons need
 to be drilled out and swapped.
Drilling out the rivets holding the short rear fuselage longerons, swapping their location,
and re-riveting them in place.

Rear and center fuselage easily match up when the longerons are in the correct position. 

Forward fuselage skins and side channels clecoed in place
Another view of the side channels and gussets.

Complete fuselage clecoed together 

Side reinforcing ribs - the wing will be installed in this location.
Firewall and top skin clecoed in location as well