Last Modified October 31st 1999

October 1999, Half a Month!

October 1st - 2nd I recall spending a large part of the weekend wishing that humans had a third arm joint strategically located between the wrist and elbow. I now have the fuel system aft of the main wheel fitted though there were a few locations where I could either see what I was doing or attach the fittings! It is amazing how many scratches you can get on your arms when trying to work deep inside the tunnel. I soon got used to working blind and was very pleased that I had the inspection plates in the underside to help me.

Instead of using the cable ties and mounts that Europa supplied I have used recycled P clips. These, when fitted on the standoffs that I made, mount the fuel lines clear of the fuselage to prevent abrasion. There are a few places that using P clips is impractical as access is restricted and at these locations I used cable ties with bases reduxed to the fuselage. At these points I wrapped the fuel pipe with self amalgamating tape and then wrapped aluminium foil around the tape to prevent erosion.

The final fuel system layout

Once I had cleaned up the work area I bonded the leading edge of the baggage bay bulkhead into place with redux/flox. To keep the piece in place I used clecos and aluminium tape.

While the redux was setting I masked off the cockpit tunnel area and then speckle painted the top of the tunnel.

I finally got around to finishing off my proof of concept landing light. By pure chance I managed to get the leverage correct first time round and the lamp very neatly extends and retracts upon demand. The actuator is a Mac S6 servo which provides a nice slow extension and retraction of the lamp. The lamp itself is a 55W quartz halogen car accessory lamp and is mounted to a D shaped piece of aluminium which forms the cover when retracted. The mounting board in the proof of concept is a piece of body sandwich and is the same shape as the available free space in the starboard inner thigh support. The final item will be mounted on aluminium sheet which will then be bolted to the aircraft skin. The inside of the thigh support base will require 4 more layers of bid cloth to be laid onto the base and lapping up the sides before the hole is opened up. As this can only be done though the access hole at the front of the thigh support I suspect that I am in for another entertaining hour or so's work.

Nathan's reaction of 'coool' when he saw it working for the first time sums up how I feel about my handiwork. My only concern was that the servo motor wouldn't be strong enough to pull the lamp up against the airflow but testing showed that this wasn't an issue as I was unable to stall the servo even when applying a lot of force on the lamp support. Only thing left is to make a support for a micro switch so that the light turns on and off automatically as the lamp moves and to come up with shorter clevis pins as the ones supplied with the servo are too long for the job.

If I get really enthusiastic I may make the angle of the lamp variable to the fuselage with a couple of preset locations to allow the lamp to be set to landing or taxi positions.

October 4th Top coated the speckle coat on the tunnel. The picture really doesn't do the finish justice as it does look very good. There needs to be another little area painted to the front of the tunnel where there is a gap in the instrument panel. Forgot about that bit!

October 5th My FloScan 200 fuel flow sensors arrived from the US today - great timing!

I checked out how and where I was going to mount these units and decided to place one on the base of the tunnel and on on the starboard side. The one on the base measures the fuel flow going to the engine while the one on the side measures the anti vapour lock return feed from the engine. The Audio Flight Avionics AV10 very nicely subtracts the return flow from the input flow to give me an actual fuel burn rate. The positioning of the sensors as I have them meets the requirement that the inlet hose should have a 'reasonable' length of straight line on the inlet hose in order to eliminate false readings due to induced turbulence in the line.

Once I had fitted the 1/4" NPT fittings to the sensors I made two aluminium brackets to support the units. The simple right angled bracket is for the side mounted sensor while the bridge shaped bracket is for the base mounted sensor. The sensors are attached to the brackets with AN4 bolts and stiff nuts out of my collection.

Next exciting task was to fit the base sensor to the existing fuel line. Tip - cut the braided fuel line to length before fitting it into the plane. My right hand now looks like I have been attacked by a wild cat. Having cut the hose to length I then fitted the sensor to the hose.

October 6th In a discussion I was having with Andy Draper I mentioned the use of clips to retain the inspection panels on the aircraft. The manual states that you can use clips, screws or sealant to attach the plates. Andy recommended that the rear panels be attached with screws for structural reasons while the underside panels can use a non structural attachment. I took the three rear panels, marked and drilled out three mounting holes in each and fitted nutplates to the fuselage to mount them.

October 7th My master contactor arrived from the UK. I first saw this on Dave Simpson's Europa and he very kindly acquired one for me. This is a 300 Amp contactor that works by rotating the rather obvious red handle. In its off state the handle can be removed and is show here in its on state. A quick flip to the left disconnects the battery positive feed from the aircraft and, in this position, it can be easily reached by the pilot simply by reaching over to the right.

The switch is lighter that a master breaker and has the big advantage that it doesn't consume 1/15 of the available Rotax electrical output like a master breaker does. For the secondary 8 Amp power system which will not be involved in engine starting I am simply going to use a 20 Amp switch located on the panel as the master.

Satisfied with the master contactor installation I laid in the fuel piping for the fuel sight gauge. This feeds off the Tee pointing into the port baggage bay, reduces to a short length of 1/4" internal hose with the fuel flow restrictor embedded in it and then meets another Tee. The horizontal portion of this goes off to a 3/16" reducer for attachment to the fuel head pressure sensor while the vertical connects to the sight gauge. At the top of the sight gauge, rather than simply bend the tube to the side I have fitted a 90 degree 1/4" hose fitting. This allowed the sight gauge pipe to be vertical throughout the height of the tank and looks a lot better. The sight gauge will be attached to the baggage bay forward face with P clips connected to hard points.

I will probably source some light weight 1/4" fuel hose for the run aft to the vent as I can't see and reason why this has to be continued in clear plastic tube and will do the same with the tube from the starboard filler vent.

October 9th & 10th

Only a bit of work on the 9th but I did manage to do the four layups bonding the bulkhead supports to the base of the fuselage. On the 10th I tidied up the layups then measure out the positions of the screw holes for the gascolator and pump supports before drilling the holes. One of the gascolator support bracket holes also holds a P clip that supports a small length of tubing to keep the rudder cable clear of the flap actuating arm. I used 1/4" bolts through the pump support plate with the heads redux/floxed in place to act as studs. The plate itself has two small ridges at the outside and these were reduxed to the fuselage base. While I had some redux mixed I bonded the support plates for the fuel flow senders into place and also bonded studs in place to support the fuel sight gauge. To ensure that I had a permanent record of the sender coefficient I engraved the coefficient into the support plate supporting each of the senders.

Once the redux had set I fitted the fuel pumps into place and then fitted two sets of metal tape to the bulkhead. The first set is an area of aluminium tape on the starboard side which acts as an electromagnetic shield from the transponder aerial. I probably don't need this but the idea is to create an electronic shadow across the passenger area from the transponder aerial. I am not concerned about the area below the back of the bulkhead as there is going to be a large lump of lead in the form of the battery located here.

The second metal tapes are two 21.2" strips of 1cm wide copper which run across the front of the bulkhead base. Admittedly the last 2cm of each piece are lapped up the side of the fuselage which reduces the optimised length of the tape but they will still work well for their intended purpose - as the ELT aerial. Why 21.2"? To optimise the length of a split dipole aerial for a particular frequency divide 2578 by the frequency in MHz to obtain the length in inches. For 121.5 Mhz this works out at 21.2". The gap between the poles is less than 1cm and will have the coaxial cable central core connected to one side and the shield to the other. Three inductors will be fitted around the coaxial cable at the aerial end to damp down return RF signals when transmitting.

I spent a few hours working on the design of my instrument panel. The design has changed quite a bit since the early days and now incorporates more automated monitoring of systems and fewer indicators.

October 11th - 15th No building

October 16th Repeated the rudder cable setup procedure to ensure that the cables were correctly tensioned following their repositioning in the undercarriage bay. Repeated the setup procedure for the stabilators and discovered that I had an interference problem when the stabilators were at their full up and trim was at full down. To fix this I repositioned the trim motor slightly higher and then rechecked the setup. I have the stabilators set to give maximum up of 12.3 degrees and 4.1 degrees down, the trim tabs work on a ratio of 1.46 and have 6.1 degrees of range upwards and 6.5 degrees of range downwards. All of these are within specification.

October 17th Clecoed to top onto the aircraft and dragged it outside. First job was to trim the port flap extension. I shaved enough off the edge to allow the flap to be raised and then marked a line 5mm from the edge of the fuselage all round the flap edge before trimming back to the line. With the starboard wing rigged I shaped the foam for that flap's extension. I dived under the aircraft to fit the return fuel flow sensor to its bracket and plumbed the fuel hose into it.

With the easy jobs done I spent a bit of time sanding back some of the filled areas on the fuselage down to 240 grit level. Next on the list was to temporarily cleco the wing fairings to the wings. I covered the edges of the fairings with tape wherever the fairings didn't fit hard against the fuselage and then filled the fuselage out to the fairing. These gaps are only a millimetre or so wide over minor areas of the fuselage and, other than on the port underside, match areas that I have already filled. Once the filler was set I de rigged the wings and will shape the filler next time I rig them.

Once the wings were back in the garage I fixed up the starboard flap foam extension where we had broken a bit off while derigging and then covered the foam with peel ply.

October 18th Did the first layup on the starboard flap.

October 19th Trimmed the foam back and did the second layup on the starboard flap.

October 20th - 23rd No building - too busy before I go away.

October 24th - 31st No building, working in Thailand