Last Modified February 28th 1999

Hopping Along!

February 1st Spent a bit of time trying to work out how (and where) I was going to fit the ELT unit into the aircraft. I have a 24Ah battery, an ELT and a Whelan strobe unit that all need to be fitted under the bulkhead area along with the fuel filters and pumps. I very much suspect that the strobe unit is going to end up sitting in the base of the starboard baggage bay due to the lack of space elsewhere. The other challenge is finding a home for the ELT aerial!

February 2nd Undid the cables from the tailwheel springs and cut the ends off. Remade the cables to position the turnbuckles at the tailwheel. Carved a foam block to form the base for the ELT support. I am positioning this on the port side underneath the lip of the bulkhead floor. There is just enough space to tuck this underneath and still be able to undo the securing clip. I won't bond the block in place until I have completed the flap setup just in case I end up with a conflict between the ELT and the flap arm. Trimmed up the mudflap that I am fitting to my undercarriage arm. This is another GFLight product from Graham Singleton.

February 3rd Cut out the ply for the bulkhead mod support brackets and for the panels in the bulkhead.

February 4th Took delivery of my battery. I am using a 24Ah Panasonic Recombinant Gas battery for this job. Europa recommend a minimum of 17Ah but it appears that most people are putting in a 24Ah battery for the 914. This adds another 61b to the empty weight but does give greater range in an alternator out situation - essential for the 914 which only has electric fuel pumps. The RG battery has a better power to weight ratio than normal lead acid batteries, much better cranking current, and due to the fact that it is sealed, can be mounted on its side. The only real disadvantage is that bench charging must be done with a constant voltage charger but I can make one of those quite easily.

Finished work on my remote RPM gauge that I am slaving off my AV10 engine management system. I wanted a large RPM gauge right in front of my nose and, while the AV10 does have a remote display, I wanted something a little larger. I developed a Basic Stamp based unit that intercepts the data stream out of the AV10 and puts the RPM value up on a remote serial display. While I was at it I developed code that will automatically set the pitch of the Airmaster constant speed prop based on the speed band that the engine is operating in. This can be overridden if required but what I have ended up with is a system that effectively gives me a fully automatic CS prop.

Note: 142psi is not a real Oil Pressure reading!

February 5th Trimmed the plywood for the bulkhead hole covers. Cut the plywood and aluminium for the battery housing. I am copying Dave Simpson's PFA approved design (Project Number 247-12622) which uses a ply base bonded into the fuselage to which an aluminium tray is bolted. The battery then sits inside this tray and is retained with polyester webbing straps.

February 6th No building. At Ashburton for the SAANZ Great Planes Fly-In for the day.

February 7th Riveted the aluminium together to make the tray for the battery. I user 2 x 1 aluminium angle for this with the 1" piece vertical. I set the fore/aft pieces as the base and riveted the two side pieces on top of these. Six nut plates were attached to the fore/aft pieces in the area between the side pieces. A strap will go underneath the side pieces to secure the battery into the box. I am mounting the battery on its side as it is too tall to sit in its base under the baggage bay bulkhead and be easily extracted. One thing I discovered (in time) was that the battery wasn't square so I adjusted the sides of the tray to suit.

I checked the position of the battery in the aircraft and the clecoed the baggage bulkhead back in place to check the height of the centre supports. I have decided that it will be easier to bond these into place on the bulkhead and then use this stable setup to determine the shape of the outer supports rather than trying to fit all four supports at the same time

While I was playing around with the baggage bay bulkhead I had a flash (very bad pun) of inspiration as to where I can place the strobe unit. The Whelan unit fits very nicely within the plywood hole cover so I am going to mount this upside down underneath the port cover. I used the strobe unit as a template and drilled four holes in the ply and then fitted nutplates to the existing 3/16" holes in the flanges of the strobe unit. Having had some feedback from other builders I am going to use a tape dipole aerial fitted immediately aft of the baggage bay bulkhead for my ELT. To finish the day I cut and bent the two stainless steel vent pipes that will be fitted to the top fuselage.

February 8th Set up the undercarriage retract arm. First thing I did was to open up the 3/16" hole in the undercarriage end of the arm to 1/4". This has to be done in a bench drill as all of the holes in this assembly must be drilled square. I bolted the lever arm to the port gear retract arm and adjusted the position of the lever arm so that I could just get my fingers underneath. Setting this in place with a wooden block I then marked off the position when the two arms met. I clamped them together then removed (not without some difficulty) the whole assembly. I drilled out the two remaining holes, adding the nuts and bolts to each one before going on to the next to ensure that nothing moved in the process. Europa issued a tech tip in the December newsletter which added a cross brace between the arms and I went ahead and made up this brace. I used 50 thou 2024-T3 aluminium for the arm with each side of the angle being 1" wide. 50 thou was the thickest aluminium that I could use with the clevis pins provided. The brace had to be bend slightly at each end as there is a 10mm or so offset in horizontal placement between the two ends. The undercarriage end is kept in place by the clevis pin that supports the damper mechanism while the upper end is retained by an AN3-4A bolt positioned 12mm up from the lower edge. Once I had finished making the brace I alodyned it and then fitted it to the arms.

The next challenge was to fit the undercarriage arm back on to the undercarriage frame. I am still trying to work out how to do this without having to take the undercarriage frame out of the aircraft!

February 9th Spent some time "trying" to persuade the reaction arm to go back on to the shaft. As these two are almost an interference fit they have to be perfectly aligned before they will mate. Once they were aligned the two slid together very easily. I fitted the roll pin that locks the arm to the shaft. I drilled the holes in the lock plate that goes on the top of the tunnel having first aligned it with the slot. I found that the forward end of the slot could be extended by around 12mm before the handle got to the point where my fingers would be trapped between the lever arm and the instrument panel. The easiest way to determine the available movement was to fit the instrument panel and then, with the metal plate removed, extend the slot in the tunnel glass forward until the limit was reached. With the metal plate refitted it was an easy job to mark the plate from the underneath to establish how far the slot should extend. I files the slot out forward and then filed out the gear down latch slot. Fitting the plate back onto the tunnel showed me that there wasn't enough sideways displacement in the arm to guarantee that it would spring into the locking slot so I am going to have to undo the lever arm from the retract arm tomorrow and increase the offset until I am happy that it will spring it to the slot. From its current position another 8mm offset will do the job as it is currently running down the centre of the slot with a 1mm gap to the starboard edge. Increasing the offset by 8mm places its relaxed position hard against the edge of the 7mm deep locking slots fore and aft.

February 10th Filed out the foam and glass under the gear down slot. Removed the lever arm from the reaction arm and increased the amount of joggle so that it would spring into the slot in the top plate and then remounted the lever arm to the reaction arm.

Having first checked all of my clearances in the gear up position I marked out the gear up locking slot and filed this out. Remounting the plate on the tunnel showed that the lever arm will now lock into the slots and travel down the slot rubbing on the right hand side as it is supposed to do. A tufnol block, slightly offset from the metal, will be mounted under the plate and glass later to act as a slide plate for the arm. Stopped early as I am having trouble with my right knee.

February 11th Waaaaaah! Grounded!! On getting out of bed on Tuesday my knee went crunch, by that afternoon it was bad enough to warrant a visit to the Doctor and the knee was X-Rayed, a visit to a Surgeon followed this morning and I was booked in for surgery on the 25th of February! Now, for some strange reason Carol doesn't think I should work on the plane if I can't stand on my right leg but I can't see the logic in that, after all you don't need your right leg to file metal! Did I ever get grizzled at when found I was found in the garage! I think progress is going to be slow this month. I have lots of wiring diagrams to work on so I'll get on with those and I can always sneak into the garage while Carol isn't looking.

February 12th Cut the tufnol block to shape. The edge of the block sits about 1mm into the slot and forms a smooth surface for the lever to ride against. I found that it helped to very slightly round the bottom edge as this allows the lever arm to travel down the slot better. When working out the angles to cut on the end of the block remember that there is a glass and foam layer between the block and the metal plate. This will save having to trim an extra 3mm or so off the ends of the block after you have done such a nice job shaping it in the first place - like I did! My lever is set up to snap into the gate which means it is rotated very slightly clockwise in the vertical access with relation to the slot when it is out of the gate. This causes the contact with the rubbing plate to be on the leading edge of the lever only. I don't think this is an issue and prefer to have it snap into the gate as this guarantees a good latch and the arm is in its rested state in the two latched locations.

February 13th Made up the latch for the arm. I found that I needed to open up the slot very slightly to accommodate the latch. The original manual is missing two rather important descriptions on the latch insert on diagram 14 which is rectified in the XS manual. The spacer is an FL10 and the screws are AN525-10R14's. The FL10 is slightly wider than the latch and I left the this sitting slightly proud on the outboard edge. I filed back the fine lip on the pivot screw so that it wouldn't turn into a finger trimmer! I also found that after drilling out the pivot hole the latch lower surface, when the arm is pulled left out of the gear down slot, was just slightly below the plate surface as a result of imperfect opening up of the existing hole to accommodate the FL10 bushing.

This made it difficult to unlatch the arm so I filed back the base until it was parallel with the plate. The lever can now be unlatched cleanly and, upon lowering the gear, clicks into the slot and drops the latch every single time with a single fluid movement.

February 14th Filed the sloped edge of the plate to match the edge of the tunnel. Mounted the damper mechanism back on the reaction arms and found that I hadn't quite drilled the end hole in strut arm in the right place so I will have to remake the strut. Lesson to learn...make the strut up to length and drill only the large hole in the end, do all the rest of the work, fit the damper mechanism and then, and only then, drill the top hole.

I now have the official documentation for the strut mod and I'll remake the strut out of aluminium angle. While I was lying under the aircraft (something I can do quite easily with my knee as it is) I bonded three cable tie holders in place for the fuel lines. The positions for these were kindly posted to the mail group by John Moran. The central one is positioned 1.75" below the aft brake cylinder bolt. Another goes forward 7.5" from the central position and is 4" below the top of the tunnel. The third is placed in line with these two midway between the central one and the tunnel bulkhead. Now, if I can work out how to get out from underneath this plane......

February 15th - 24th No building. Knee out of action. I have been able to spend some time working out the finer points of the design of a retractable landing light while being laid up. I have a really neat looking 55w quartz halogen lamp which is housed in a 63mm ball. The design concept is to have this drop out of the starboard thigh support on demand. I have the basics of the design working and am still toying between a simple cover which drops with the lamp or go fancier and have a cover which swings down perpendicular to the lamp hinge. I have checked the spacing within the thigh support and also checked with Andy at Europa as to how much reinforcing I need to allow to cater for the lamp retraction hole.

February 25th No building. Knee operation.

February 26th - 28th No building. Post operation recovery.