Fuselage Skin Repairs
As previously mentioned, in the airframe survey documentation, corrosion is mostly limited to surface oxidation on the outer skin. Magnesium castings are generally degraded in most areas, though the majority can be treated and re-used (those mainly limited to the gear bays). Only 3 major corrosion areas have been identified on the aircraft.
1) Spine panels. Badly corroded and require replacement (magnesium Alloy)
2) Starboard top wing skin.
3) Cable loom covers port and starboard (magnesium Alloy)
Areas 1 and 3 are relatively simple to repair, just requiring re-skinning of existing structural frames. Area 2 is more problematic and will require approximately 200 flush rivets to be removed from the top wing surface, and removal of the under wing strengthening plate to gain access to corrosion. Though no corrosion is evident in this area on the port wing, it will be de-skinned anyway to inspect internally as a precautionary measure. (See the following plates)
1) SPINE SKINNING:-
53-671 (ZF579) shortly after re-assembly. Above plate shows heavily corroded spine panels, worst being the largest, the engine starting equipment compartment.
Existing frames re-skinned using non magnesium based aluminum panels. Yellow paste is anti-corrosive jointing compound.
Above: Shows flush riveting being used on new panels
Permanent Skins were de-riveted and removed from aircraft, leaving frames behind
Engine starting compartment, spare hatch being prepared for final painting.
Above: Newly prepared, Engine Starting compartment hatch fitted.
New spine section skins, fitted
Finally the spine sections are to be liberally sprayed, internally, with Castrol Rustillo anti corrosion agent, the spine section will also be covered during the winter period to further help against any onset of deterioration due to weathering.
07/03 Spine sections sprayed internally with Castrol corrosion agent.
(2) S/B WING
Below plates show lifting of top wing skin caused by trapped corrosion between outer skin and inner strengthening skin, in the Starboard wheel bay, and subsequent removal for restoration. Corrosion treated with de-oxidine200.
Top wing skin damage. Caused by tensional stress from advancing corrosion below, resulting in the ‘popping’ of rivets, as the next plate shows.
Corrosion trapped between inner and outer skins, forcing top wing skin upwards. Below plate shows trapped corrosion, with spar bracket removed for clarity.
Removal of top skin flush rivets (approx 200) to separate structural inner plate from the top skin.
Above: Bay before removal of equipment and bottom skin
Above: With lower strengthening skin removed, the trapped corrosion along the rivet lines is clear to see. Corrosion will be removed and the skin treated. Rivet lines will receive a generous coat of anti corrosive jointing compound before the upper and lower skins are re-joined. The cause of the corrosion is most likely due to moisture ingress and perhaps too little jointing compound during manufacture.
08/07/03
Top wing skin cleaned and treated with deoxidine 200 aluminum corrosion treatment.
Top skin examined for previous strain buckling. Removal of tensional stress has now allowed the top skin to settle back into its natural shape and is once again flat.
09/2003
Below, shows gear bay corrosion being treated with deoxidine 202 and celenious acid, ready for painting.
Below plates show etching and top coating of repaired gear bay skins.
10/11/05 Above: Gear bay begins to take shape with fresh coat of paint.
Structural inner skins re installed into starboard gear bay. Ancillary subsystems now follow.
Above: Refurbished inner skins re-installed with original rivets sourced from battle damage repair pares.
Above. First of the two inner ribs skins refitted and riveted.
Below. Both inner and outer rib skins now fitted (yellow colour is JC5 jointing paste)
With skins fitted and riveting completed, gear bay ancillaries are fitted next.
Above: skin repairs complete.
06/2004
Upper and lower radius rods re-installed. Main leg stripped and re-painted.
Leg fairing undergoes refurbishment and re-fitting to airframe
Above. Main leg stripped, corrosion treated and re-painted. Radius rods installed
Main fairing restored and refitted with new magnesium castings and new taxi lamp assembly. See below plates
Above. Door fairing undergoing strip and refurbishment
Below. Magnesium castings being replaced with serviceable items.
Below. Newly refurbished door fairing installed on airframe, with new taxi lamp assembly
