Wednesday 30 December 2015

A bit of Chrismas cheer.

Welcome to my last post of 2015.  Although it's the Christmas holidays and I didn't foresee much progress, I got in a few hours before Christmas Day and a few more since then, so I have been able to get the tail cone completed and my next stage inspection passed by Jerry.  As I don't have a target for completion (it's meant to be a fun hobby after all), I'm pretty pleased with progress so far.

First task since the least visit was competing preparation and painting of the remaining skins and top rib.  

Fitting anchor nuts to the fin attachment rib which will go on the top tail cone skin

After the upper side skins were pinned in place, it's time to start out-fitting the tail cone. There's not a great deal in the rear - control cables for rudder and elevator, wiring for the electric trim, nav antenna cables and static pipework.

Strings fitted to pull-through the elevator and rudder cables (in about a year!).  Also installed the pitch trim electric cable loom and the static port pipes to the ADAHRS. 

You can just make out the inside of the left static port.

This is the right static port from the outside - it's a pop rivet with an over-sized head and the mandrel pushed out. 

Now the final top skin is pinned in place, all holes match-drilled and then the skin removed again to deburr the holes.  Finally, it's back on again and ready for riveting.

Top skin clecoed in place and ready to rivet. 

You can see the remaining pins securing the skins to the fuselage frames.

The completed tail cone ready for inspection.

A top view of the fin attachment rib.  The skin below the rib has been primed to prevent corrosion.  The antenna connector is for the nav antenna in the fin cap, and allows for easy installation or removal of the fin.

Inside the completed tail cone.

My next job is to skin the horizontal stabiliser (HS).  The skins are already prepped and painted.  Moving on, it'll be a trial-fit of the fin/rudder and HS to the tail cone.  At this stage, it will look like the complete rear-end to an aircraft!  Once this is done, I have to deal with the trim motor mountings and then make the tail cone fibreglass fairings fit (apparently a bit long-winded to get good alignment with all of the securing brackets) .  I reckon this will take me to the end of January, and then it'll be time to start on the wings.

To all readers - thanks for visiting and my best wishes for a Happy New Year.

Monday 14 December 2015

Back underway

Unfortunately I've had an unscheduled delay due to hand and knee pains.  
After a bit of medical investigation, it transpires that I've got arthritis in the hands and right knee, and other problems with my left knee!  However, after a large steroid jab in the backside and a couple of additional weeks waiting, my hands at least are improving, so it's back to work.  Fingers crossed the jab will work long-term - only time will tell.  
These problems all started before the kit arrived, so I can't blame the aircraft.  The physio looking after my knees reckons it's because I've stopped flying a desk and got active after many years being sedentary.  

First job on re-start was to complete the trial fit of the horizontal stabiliser skins and match-drill all final holes prior to painting.


This is 8 feet wide.  I think we might have a problem getting the aircraft assemble in the garage!

Next job was to assemble the rear bulkhead which has the hinge bearings for the horizontal stabiliser, plus the rear tie-down bracket, hinges for the trim-tab motor and the main attachment for the fin.  It's a double-skinned assembly with loads of rivets of different types and sizes, so great care needed to get the right ones in the right holes.





So moving on and it's time to deal with the biggest part so far - the rear fuselage cone.  This is about 9 feet long (it goes from the back of the cabin to the tail) and has nine individual skins and three frames plus the bulkhead.

First step is to assemble the previously painted frames.

The finished frames.  The V-shaped bracket at the top of the smaller frame is where the front of the fin attaches to the fuselage.

In preparing the skins, I came across an issue which turned out to be a factory error - a first in what has been incredibly accurate production.

We have to fit some J-section stringer extensions to the bottom skins.  As you can see, the holes don't line up.  I thought it must be my mistake as the holes are fine with the stringer outside the skin, but the pictures suggest otherwise.  A review of the builders' forum showed this to be a known issue and my assembly was correct.  It then became a simple re-bending exercise with a couple of blocks of wood and a rubber mallet and all is now good!




Next is to trial-fit the bottom skins.


Then after final match-drilling and deburring, it's time to assemble and rivet together:



The finished product with all lower skin panel rivets installed.  The ones marked with tape and kept for joining this section to the main fuselage.

Now we get to turn it the right way up and start building up the sides.


 Looking inside at the rear bulkhead.  A large counter-balance will protrude through the bulkhead when the horizontal stabiliser is finally installed.

The rear view showing the horizontal stabiliser bearings.

The next job is to add the wiring and plumbing for electric trim and static system, plus the nav antenna cable, before the final skins are fitted.  The next few weeks probably won't see much too progress as the day job beckons with deadlines and of course it's only 11 days to Christmas!