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.

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