Sunday, 27 January 2008

A new interior - Floorboards

I've been sidetracked so far this year with three other projects, a new car, an AD on Taylorcraft lift struts and the small matter of someone trying to build a new town on our airfield but I have at last managed to make time to start work on the aircrafts interior. The old interior was not unattractive or particularly tatty, but I feel that it could be better in a number of ways. The floor was the original aluminium which had been modified over the years and then covered with carpet. This will be replaced with a 6mm birch plywood flooring and aluminium kick plates.

Working on the principal that everything will have to be done at least twice before it works I set about creating a template floor in cheap 5.5 mm plywood first. This will then be used as the template for the final floor. First the shape of the current floorboards was transferred onto the onto the plywood.

I used a hole cutter and fly cutter to get the shape around the heel brakes. The rest of the cutting required is just straight lines at various angles.

I used a jigsaw to cut the straight lines which meant setting up a straight edge to help guide the saw. The calipers have been set to the distance between the edge of the jigsaw footplate and the saw blade. Once set this is used for all cutting.

Once cut, the floorboards (which are in two halves so that they can be removed) are laid out. I will have to make some fine adjustments before I am happy with the fit, mainly because the old aluminium boards overlapped and the new plywood boards have to but up to each other. This photograph shows the two floorboards in situ with work still required.

The bulkhead will slot into a grove formed by two quarter round strips of wood that will be glued in place. A battery box holding two sealed dry cell batteries will be fixed in the center of the bulkhead where it shouldn't take up too much space and will be easily accessible. It will also help fix the floor and bulkhead in place.

I still have to manufacture the kick plates and battery box before I'm confident that I can finally make the floorboards.

Tuesday, 1 January 2008

A new year and the first sign of trouble

January 1st begins pretty much as 2007 ended - foggy - so I'm back in the workshop to finish off removing fabric. All that remains are the rudder, horizontal stabilizers, elevators and undercarriage legs which shouldn't take too long.

The undercarriage legs had been recovered a few years ago when I discovered some corrosion and had to have sleeves welded over the corrosion so I don't expect any serious issues here.

Unfortunately as I began to strip the various components it soon became clear that there is serious corrosion in all the tail feathers and that these will all require time and effort to sort out.

The rudder was the only area where there was a visible hole in the tubing although I have not carried out a punch test on any of the other sections of corroded tubing yet. It appears that moisture must have been getting through the fabric for some considerable time but because of the thickness of the Razorback fabric it was not obvious during any of the previous 9 annual inspections.

Horizontal Stabilizers
The horizontal stabilizers are mainly corroded around the fuselage attachments which means they cannot have an internal sleeve welded inside. Note that in the second photograph the repair is to a curved tube which will be more difficult to achieve.

Similarly, there is a lot of corrosion around the weld clusters which will be much more difficult to repair and will probably require new U channel pieces and tube.

With so much work to do, I will have to get approval from Carl, my inspector, for each repair method. The repairs must also conform to AC43.13-1B to ensure that structural integrity is maintained. For the moment I will try to reduce the opportunity for the corrosion to get worse while I try to figure out how to repair the damage.

Strangely, this has not depressed me but has confirmed the need to renovate the aircraft in the first place as I now know that in places it did need it after all.