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