Bit of a wobble ….

A few months ago, on rollout from landing I felt a slight vibration through the frame … this soon stopped as the speed fell away to walking pace and nothing further ..

I had a quick pull and push of the wheel on parking up but couldn’t really feel anything so shrugged it off as a possible ‘too quick’ landing that had induced some sort of oscillation .. somewhere ….

I flew again early September with Will , no 2 son, and we flew for about an hour over the South coast and on returning to runway 08 at Jersey the slight wind on departure had become 15kt from 360’ … not ideal … on the final bit of approach .. Will said .. “you have control” … he’d done a great job crosswind crabbing to that point

In the final 100’ we entered a bit of down draft and lost about 30’ before my early application of full power pulled her out and we rounded out in ground effect .. just a smidgen too fast ..perhaps around 55 ..

The wheel wobble , shimmy returned .. and was quite pronounced .. going away when we slowed down ..so on hangering I had a really good look and jacked up and removed the port wheel. This showed that the out wheel bearing had just started to show signs of degradation … ie the smooth black cover that circles the roller bearings was slightly uneven on one side .. the outer side.

On reflection running large, low pressure, sticky tyres on a very grippy concrete runway at Jersey for the last 3 years and a total of about 195 landings and miles of taxiing … may just be a little too much for smallish bearings .. which probably expect to be on grass most of the time

Tool for pushing bearings in

Unfortunately the earlier failure of the bearing meant that the wheel hub centre became rounded out and so needed to replace 2 centre hub shells

Air Display 2019 – Static

Pattern full this year so did static display both at the airport on Wednesday and down at the sea front on the Thursday

What looks like the whole of year 1 from a local infant school .. “Who wants a go in the plane” .. they ALL do 😁

The early start was meant to get the aircraft out of the hanger .. taxied up to the fire security gate to meet my colleague James Varrie who had kindly hitched the trailer on

Slight issue .. just as the aircraft got loaded we noticed the trailer had a flat tyre … horror ! James contacted the fire rescue guys .. one of whom had a battery driven pump in his car .. star .. he kindly got it, pumped up and all was fine .. it stayed up for the day and in fact to this day .. one month on .. so suspect it may have been tampered with ;(

Rigging .. 3 years on

As the weather outside is around 26 gusting 40 something it seems a good time to get some maintenance a and checks done.

After rigging 18 rigging wires on the ‘plane a number of years ago I was not quite happy with one of the flying wires as opposed to landing wires on the wing .. by the time I tightened everything up to meet the 3 degrees lower wing dihedral one of the turnbuckles was just at its limit… it was fine but would not give me any real adjustment options should they be required.

Well, 3 years on … and checking the dihedral and incident boards and it remains spot on… but I still felt the need to replace that one wire …

Aircraft was put into the flying position and tethered and tressled to stop it tipping up on its nose

Get the tools ready… and cable and ferrules and thimble

Including incidence and dihedral boards

Then set to work gaining access … to discover I had added the access ring below but not cut it open .. nor added a second to allow two hands in to manage nuts around the main spar

Crimping done and making sure everything is threaded onto the cable in sequence … guess who ran out of black large heat shrink !

Be careful to thread and cut the correct (old) cable

Tidying … post oil change ground run

Post my engine oil change a ground run to temps to check for leaks and then put cowlings back on.

You never stop ‘doing things’ there are always interesting and useful things to sort out …

Ages ago I started with nice long braided oil cooler hoses but this was all changed when the cooler was re positioned and resized… I made up temp rubber hoses .. that was 3 years ago … need to get braided ones back on …

Also, I was never happy with my wiring .. it works .. but it’s not something I think looks particularly neat … will get some education and training in that area and re work …

Early signs … investigate..

I’ve had an annoying little crackle in the headsets for a while now but have had trouble pinning it down .. at first it was just a low level occasional click but has increased over recent flights to being quite invasive.

When I transmit or receive the radio goes clear as a bell.

Chatting with our visiting avionics specialist he suggested trying to isolate it by turning off circuits and devices and checking to see what happened .. problem was it was definitely more noticable airborne … so not so easy to start wholesale switch offs !

In the end .. the progressive nature of change … I noticed that if I turned the right mag off the click pretty much stopped .. so we had an area to focus on .. but no one in Jersey has a Jabiru and the forums are flooded with conflicting advice …

I also noticed on the last flight that the right mag drop suddenly increased to about 100 .. where the left was only showing about 40 drop ..

Time to ground her and check before any more flying ….

Time to call Paul H Smith at TLAC for a quick bit of advice…

Given the symptoms, he advised to check the Jabiru remanufactured HT lead and fitting out of the mag and, if that looked ok, double check distributor cap and rotor arm

In 5 minutes I’d located the problem … the right rotor arm was clearly not seated firmly and could move ever so slightly ..

At the first 25 hours of engine run time I had been super cautious and changed oil, filter, plugs, rotor arms and distributor caps. The arms were very difficult to get off .. later found they are epoxied in place ..

I had applied epoxy .. sparingly but, I guess, too sparingly … and this arm could move fractionally on its squared stem drive shaft.

Removed, and temporarily put back the original 25 hour unit having cleaned and epoxied

Engine start and run up … radio clear as a bell again …

Also .. Left and Right mag drops back to evenly matched at about 40 rpm each 😉

Fun in the clouds at 3,000′ post permit renewal

Saw that the cloud was clearing and rising so nipped out to buzz for a while

Then back for oil change at just over 25 hours again … decided the cost of changing every 25 far outweighs the short time it takes .. and gives you a great chance to keep on top if things

Day out …

So .. today was a different day … with the great help 2 of my boys Sam and Will …and a myriad of Airport Security, Fire and Rescue services, Jersey Air Traffic and the Jersey Aero Club, we managed to blow the dust off the trailer after 2 years .. and make great use of the fantastic alloy / carbon fibre wing supports … really steady …

Some shots from 2017

Just tidying some photos up to make sure I don’t lose them … you can see these are minus the root fairings … so pretty early flights ..

DCIM119GOPRO
DCIM119GOPRO
DCIM119GOPRO

D Day (Landing) 6th June ..

Nice bit of crosswind .. around 10 knots … Wills pretty much flew the whole thing and brought it in nicely .. also helped as he counted down the airspeed on approach … probably landed a shade too much speed … and a fair bit of rudder at the end … this ‘plane certainly teaches you good use of rudder

As mentioned in a previous post the cowl is a ‘re use’ of the original that I discarded after over trimming. On this flight (just under 90 mins) I was keeping a close eye on engine performance and temps … it takes a while to ‘settle’ any aerodynamic change and switching your cowling isn’t just a paint job !

Turned out to be quite close .. but did run a little warmer than usual .. and at one point reached 97’ on the oil temp … that turned out partly to be the cowl and partly Will was flying slightly cross controlled … “Ball in the middle” sorted the airflow and we dropped 4 degrees almost straight away.

I’ll double check the baffles at the front are not inhibited and that the cut out openings (which look fine) are indeed as large as the original cowl.

Plan to fly with this one for a few weeks on and off

(Another thing I noticed … in the sun .. the Matt black gets super hot compared to the plain white … really absorbs the heat)

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