Its really handy being based at such a busy small strip like Priory Farm as many people pop by and we have a wealth of great knowledge across all sorts or skills around light aircraft.

One such ‘pop in’ is Clive who has great experience of Jabirus and spotted that one of my cooling ducts had a gap at the back that you could just squeeze your fingers through.

This would mean that the air, being squeezed through the front cowl ducts would effectively whizz through..and, having got a ‘shiny’ new multiple 4 way CHT monitor .. I can see that Rear Left Cylinder Head (number 4) is running colder that the others

Clive.. very kindly said he would drop some heat resistant padding next time he was passing .. fast forward to last weekend and in zooms a lovely slick RV .. and touches down at Priory .. out steps Clive with 4 pieces of this rubber of varying sizes! What a gentleman !

Duly secured .. will monitor the difference before adding more… small steps and check each step 😉

Just checked and its over 8 years ago when I first glued the fin and turtle deck covering on… not an easy task as it was 1 long piece per side.

My old post shows the details and (quite handily) the exact temperatures I used at the time.

I wasn’t expecting to undo it … ever .. but, needs must and with some judicious use of the heat gun and easing it off at around 160′ to remove the top pinked doubler strip

Then, similarly ease the overlaps off that were put on so long ago ..

Once the rib had been replaced I cleaned down the previously glued areas of overlap and applied fresh hotmelt glue

Some of the overlap had doubled over at the edge and stuck fast so trimmed a couple of mm off to neaten the edge.

Then, using the heat gun, heat the material overlap and new fin glue edge and press down with the heat matting.. making sure I was pulling it as taught as I could.

The bond was super strong.. and the remainder of the fin started to tighten.

I then left it to cool … overheating at this stage could pull the ‘just bonded’ overlaps.

Pleasantly surprised that the Oratex was so forgiving to a fairly major movement and return !

It’s always good to get the annual test done and dusted but it’s also a time where things might crop up .. it might be recent or it might not …

A few things came up and one particular one was a bit of a pain ..

A while back I wanted to fit a go pro mount and had seen some really good ‘tail looking forward footage.. so drilled a mount and all was well

Unfortunately this is a ‘non standard’ mod so I can either somehow do all the official stress test analysis and load testing and submit to the LAA for approval or … remove and replace it !

As approvals are not the fastest thing to go for I opted to remove and replace the single bar fin leading edge

I’ve not undone the Oratex much before and it was stuck like rock .. judicial use of the heat gun to remove the wide pinked cut band overlay and then start to get the edge of the material loose

An earlier post in this blog shows how I feathered the overlap on each side of the fin to ease the complex curves .. this all needed releasing now

All the time I was thinking I didn’t want to over stress the removal as I was intending to put it back and re tape the join cover

The factory had the replacement material in stock but NOT a trimmed and pilot holed part.

TLACs Emma raised a works order for part T53 .. the final leading edge and 20 minutes later I was in front of the cutting tool with the amazing Chris

Part duly cut .. 2 pilot holes .. and lined up in the now open fin area.. clecos applied and drill through the 6 x M62 large rivets and 6 M41s

Just need to get the 2 new lower brackets paired and shaped and aligned for pilot hole marking and drilling

Last task of the prep work for the annual .. the LAA now want a mass of captured data and settings and measurements..

I’ve not captured the engine leak down test before but The Light Aircraft Company kindly leant me their leakdown test kit

We have a compressor at home and so read up about getting the prop to Top Dead Centre TDC, removing each rocker cover so we can see when the valves were compressing (opening) and lifting (closing) and both closed

Connecting up the pressure test .. introducing it to the exhaust cylinder .. having removed the spark plug

Pressure released to 80 and check leak down in 2nd gunge.. 70 or more on all 4 cylinders .. Great … 👍

Time for the annual flight test .. a sort of normal flight and then a long climb up through 1,000, 2,000 to just over 3,000′ and time the climb

Getting about 500fpm and, at the top of the climb … decide to to the stall checks

A couple of reducing to tick over and holding back on the stick to get to the stall … slight buffet at around 40 and then slow mush at 35

Then … push the nose over and down to check VNE .. max descent speed … listed at 100mph … after a fair descent .. and no drama .. I chickened out at 95mph

Post the flight I thought it sensible to check for leaks and engine bits

On analysis I spotted a small smear on the outside of the rear left pushrod tube guide

After taking the rocker cover off I couldn’t really see anything obvious so rang Kev the specialist and opted to remove the head and check

On removal I could see small trace of oil on the lower bolt area .. 6 bolts hold the head in place

Removed and cleaned down with some wire wool which easily cleaned all the head faces and bolts and fins

Put it all back together … very careful to make sure no rubbers were nipped and rotated as the head was tightened down

Ground run and all CHTs spot on ! Great to get fix … flight test next

Reckon the problem was waiting 5 hours before first torque check.. so plan to torque check every flight or 1 hour for the first 5 hours

I’ve not written about why I have sourced and fitted another Jabiru 2200 but I had a slight issue with my previous … it dropped a valve seat and then had an unexplained issue with a piston which decided to dismantle itself

Slight problem was we were 2 up, Will was in his second only time in the rear (as part of my training to get him to soloing) and we were 1,100’ N of the field

The wind was between 5-8 Southerly and so an immediate turn back .. with almost zero power but a still running engine was initiated ..throttling back to try to analyse the issue

We both calmly discussed the issue … Will initially saying ‘Your aircraft’ … having already made the turn for home within seconds of the first rough running

I had Wills work bag on my lap in the front .. so space was at a premium and I certainly couldn’t hold the stick and throttle and fly with the bag … so elected to hand back to Will and govern throttle and course whilst he flew

We ran through the guage readings as we inexorably descended, now downwind, back towards an impossible to reach threshold.

Having exhausted options as to what was wrong … fuel, mags, switches, nothing … I advised to tighten the harness straps right up as we would probably not make the field

A minute or so passed and almost impossibly the very shallow float angle and supreme lift ..and it looked like we had a great chance of just making the field

Will held off to perform an almost perfect 3 pointer … and I advised to kill the mags … the ‘plane rolled to a silent stop a few feet into the upwind end of the runway we had just departed from

Engine was inspected as it cooled and removed that afternoon to drive up to Yorkshire for tests

As the rebuild ..new valve seat, new piston, liner, rings, valve, push rod and Conrod was going to take a while I sourced the spare .. all the way from Shetland