Always checking

Whilst cleaning the oil down and covering her up for the unknown time associated with Covid19 epidemic I noticed that a couple of the tail rigging wires didnt seem to have the twang they used to …

The construction has a really neat way of getting these just right in the tail .. using packing washers

You have 8 cables 2 each side top and 2 each side under providing a nice tight geometric taught support for the tail plane

Slight problem is .. there are no turnbuckle.. as this would not only weight but also drag ..

So you make each of the 8 wires to ‘exact’ length with thimble and crimps and use 2-3 washers to pack ..

Once in situ .. you hopefully have it all nice and rigid .. problem is that moving any 1 affects ALL in the setup .. beautifull engineering and geometry.. but a pain 😊

Anyway .. removing 1 washer from 2 and bingo .. the whole setup was making a nice ping noise again when flicked with a finger .. the acid test

Drip tray

When you go around Duxford you see all the beautiful old aircraft like Spits, Mustangs, Hellcats etc all with small metal drip trays under their engines catching the inevitable oil leaks and drips post engine runs…

My engine is pretty ckean having done less than 90 hours but … if I use smoke .. no matter how much I wipe down afterwards.. I get the excess dripping in a neat line on the hanger floor .. going to have to think of something for those days I use smoke 😊

Smoke oil excess

The slight downside to using the smoke is that it doesn’t quite burn everything… I’ve been using a setting of 1.5 turns on the mixture and the first time the smoke density was really full but left quote a lot of wet on the underside afterwards

Because of where the exhaust stacks end and the associated airflow around the body and rear wards.. the underside gets a film from the wing trailing edge backwards

It wipes off really easily but the undercarriage is also smack in line as well and the leather boots around the bungees catch quite a bit

I’m going to try a slightly different mixture setting.. say 1.4 .. then 1.3 but I also think I need to test this in different ambient temps as well .. last test it actually rained so not a great day for testing!

Also .. I’ve invested in a slightly retro looking can to hold a small amount of smoke oil on site .. prob holds about 3 mins worth so around 3/4 of a tank

Sorting files

I guess with any build .. this being my first.. you have absolutely tons of paperwork and guides and plans and pictures and write ups and research ..

It culminates in you writing to the LAA – Light Aircraft Association – asking for approval of the paperwork and signed papers BUT also specifying WHO is actually going to perform the test flight …

I, for one, couldn’t contemplate handing over the inaugural test flight to someone else … call it pride.. call it worry .. putting someone else’s life on YOUR construction!

So .. I requested me as test pilot … based on my previous .. but very old 5 years of Stampe biplane experience

The LAAs Chief Engineer, Francis Donaldson sends a carefully worded letter which is supportive but also says things as they are …

2nd smoke test – Rear facing camera

With some pretty grey skies over Jersey and a reasonable breeze of 250/15 so only 20′ off runway heading… I put what was left of my smoke oil in the smoke tank … filled up the fuel from my standby Jerry can … and started up

This was initially without the top and bottom cowl on just to check the head re torque and rocker cover retightening I’d completed

Turned out well … although at 1.5 turns on the oil mixture .. I think the smoke looked slightly less dense than last time .. so I’m wondering if, in damp wet conditions the mixture may need to be less ?

It was certainly damp and ended up, on return to the circuit actually raining… interesting experience

I’ve been in a Stampe in heavy rain and even hail before but this started as just sea fret then built up and was washing over the front screen and sides … inside you actually stay quite dry but, the recent clean I’d given her meant the rain just flew off the Oratex covering.

Ended up being held in the bay just off centreline and base leg as an abort on the runway by another light aircraft caused a double runway inspection and held me off south and a Blue Islands Training ATR off North as the rain came down yet again .. the Joy’s of winter flying …

Landed with a smile tho 😊

One comment on my You tube post …

3 short 2 second bursts … makes my ‘plane look fast !

Smoke – Sign off by LAA

Today .. Monday 9th March I received an email response from Francis Donaldson at the LAA 6 hours after I had resubmitted my updated Pilot Operating Handbook notes for the smoke system …

Just need some good weather and MORE baby oil !!

Mags – cleaning

The really useful course at Skycraft covered some sensible – regular- checks I could do around mags ..

Turns out this is especially good in moist environments.. so on an island of 9 miles by 5 miles surrounded by sea probably constitutes as ‘moist’ … add to that if course salt air … and you have good properties for corrosion ..

Checking the magnets on the flywheel is really simple with the cowling off and sure enough.. rotating the prop to reveal the magnets showed a fair build up of rust …

As Dave noted .. this could be a cause of radio noise.. and I’ve been having that creep in in last few months… probably proportionally ‘noisy’ as time passes… and surface rust builds …

Long long overdue wash

Every time I’ve gone up to the hanger .. with good intentions to wash the ‘plane … then you get reasonable weather to fly… you fly .. of course … so that means I haven’t washed her since before Christmas !!

So so dirty after all the dust in the hanger….

Also… after 3 years of flying .. it’s good to double check for any little lifting of the small pinked edges… and iron them flat

Engineering Day – Skycraft Jabiru Course 1

What a fantastic day with a great bunch of people ….

Flew out from misty foggy Jersey yesterday to even mistier and foggier Gatwick and then long drive up to Holbeach to stay in a small pup overnight ahead of today’s starter course for those who want to know a bit more about the Jabiru 2200 engine.

Started with lubrication … a very good place to start …

Next … electrics … not everyone’s favourite …

Next … mechanical bits … valves and tappers and compressions ….

Other useful bits to write up from my little notebook.

  • Oil breather pipe should rise initially before dropping away to catch bottle …
  • Oil excess overflow should not have a drain pipe that could end up pressurising the crankcase
  • Carb balance air pipe should come from filtered side of carb and into filtered side of air filter …should intrude by 20mm for good fit
  • Check the carb is earthed to engine
  • Flywheel bolts now have special new nordloc washers and new bolts ..old bolts need changing at 100 hours .. new ones won’t … the old ones could well be difficult to get out…remove spider … heat can be used to break the loctite .. but .. make sure you protect the magnets .. once heated .. let it cool right down first before trying to break the seal
  • When setting tappets ALWAYS do it cold .. so good plan .. drain oil hot from a run .. leave overnight to fully drain … then take a plug out to reduce turn pressure on prop and get piston to TDC then adjust as above
  • Good idea to make a mark on stator for where TDC is per cylinder
  • Check the small bung grub screws inside the tapper cover head .. these can come loose and cause oil to spill down thetappet pushrod guide tubes .. think I may well have this on mine !
  • Push rod tubes are rubber o ringed at bottom and circlipped at top
  • When replacing the inlet manifold rubbers .. prob best to cut the old ones off .. remove jubilee clips … then a bit of grease and turn the outer manifold pipe through 45’ .. it’s only on a rubber o ring to turning it makes new pipe slip on really easy
  • Note .. when checking torque on ALL cylinder head bolts .. start at 23 ft lbs and remove the bung acts which allows long drive access to 5th head bolt for torquing
  • All electrical parts should be Bosch .. distributor cap, rotor arms etc
  • Remember the ‘hidden’ filter in the pump
  • Oil pump return valve spring and fitting … push check … to make sure it’s free moving
  • Jabiru carb needle jet options … AUS vs U.K. … N2 for U.K. with fully tapered jet needle vs single bar straight sided needle for AUS market and weather conditions

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