31st August 2011 - Fuel tank installation

The fuel tank is now permanently installed in the aircraft. First job was to locate and attach neoprene rubber protection strips everywhere on the fuel tank where it could conceivably touch the fuselage structure as the aircraft vibrates in operation and also where the cables run between it and the firewall. Then the fuel tank was slotted into position and the support straps positioned and bolted to the tabs on the cross member at the top rear of the tank bay. The controls were inserted through the tunnels in the tank and through the firewall and the nuts which secure them to the panel tightened. The 1/8" tubing for the primer were also passed through the firewall. The inlet to the primer pump was terminated and attached. The outlet will wait until the engine is attached as the far end has a brazed on nipple which must be screwed into the primer lines to get the length correct. A length of 1/4" aluminium tube was connected to the tank breather inlet in the filler neck and routed behind the firewall to the breather inlet under the floor on the right hand side of the front bay. Next the fuel system was connected using 3/8" aluminium tubing from the tank to the electric boost pump and then on to the gascolator. I think all the preparation work on the aircraft wiring and plumbing has worked well - the installation looks neat and tidy - not normally my strong point!  Next job is to plumb up the vacuum instruments and I think I'll also insert some plastic tubing round the control cables through the fuel tank to avoid any risk of chaffing.

30th August 2011 - Painting some of the interior

I want to final install the fuel tank and run the rudder cables before covering the fuselage so I needed to get the tank painted together with one section of the floor which the rudder cables run through. Today was dull but dry so it was an opportunity to get these done together with some other bits and pieces. The paint is a catalysed polyurethane which dries to a hard finish. As usual painting outside a selection of the local flies decided to embed themselves in the wet paint but hopefully these will polish out once the paint is fully dry.

29th August 2011 - Left flap and aileron - all welding complete!

I think I have just completed the last welded joint on the airframe. This was the attachment of the small plate round the aileron hinge top surface to provide a flat surface to attach the fabric. This completed the left aileron and flap assembly which was constructed in a similar fashion to the right flap and aileron. This is another of those jobs that I have been putting off. The construction is not particularly difficult but does require a lot of cutting, fitting, melting and pouring lead, brazing and welding. The trailing edge which is folded stainless steel is brazed on and brazing always needs significant clean-up to remove any residual flux - another job I dislike. Now that the metalwork is complete I can take the last few pieces to be sandblasted ready for priming.

7th June 2011 - Autopilot servo and aileron stops

The Trio autopilot servo was final installed with the linkage to the control column. This will provide wing levelling, course setting and GPS following. It is critical for servos that the linkage cannot go "over-centre" and get jammed so the wings were temporarily rigged to set the aileron travel and stops set up using Delrin rod mounted on 3/8" tubing stubs and secured using cotter pins and washers. With the correct aileron travel set the servo arm moves through an angle of about 45 degrees either side of the middle which should be adequate travel to provide plenty of control whilst being absolutely within safe limits. The top picture provides a good view of the way the cable routing works and keeps the cables out of the way of the controls. The bottom picture shows the Delrin bush within which the flap torque tube rotates.

31st May 2011 - Finishing the lift struts

The lift struts had been cut to length and the top tack welded when the wings were first fitted to the aircraft Fitting the lift struts
However, the top end needed to be final welded and a supporting rap of 0.071" steel sheet cut and bent to fit to provide additional strength. This was a fairly long and tricky bit of work that I had been putting off for some time. However, a satisfactory result was achieved and the struts were test fit to the wings to ensure that the shoulders of the struts fitted properly into the brackets bolted to the wingspar.
Then the hinges for the left aileron and flap were cut and welded. As with the right wing a fillet of braze metal was run into the acute angle of the hinge to ensure that the joint was robust. You can see in the hinges holes drilled in what will be the top of the hinge - these will be used for lubricating the hinge.

12th March 2011 - Installing the stringers

The stringers provide support for the fabric covering of the fuselage and help create a curved shape. They are made from 1/2" aluminium tubing and are pop rivetted to the semicircular support tabs welded to the frame. This means that the outside of the tube that will support the fabric is completely smooth. There are three stringers along the top of the fuselage and two on the sides and bottom

28th August 2011 - English Summer

I've had little chance to work on the Tailwind recently but hopefully will now be able to get going again. I have managed to get a bit done over the last few months so will post a few updates to catch up on progress. The weather forecast for today said sunny periods in the morning with light drizzle from 16:00 onwards. This was the scene at 11:00 in the morning! I had installed the left wing to start rigging the flap and aileron when the "light drizzle" started. With the help of my wife and next door neighbour we got the aircraft covered and 20 minutes later the rain had stopped so no damage done but having to work outside is a bit limiting