As Storm Jorge “batters” the UK (also known in Scotland as “get your bigger coat on”), and with the aircraft having its annual inspection, there’s not much flying going on. During a session of distraction on the iPad I came across a trip report where two members of the Ulster Flying Club at Newtownards flew an RV7 down through France, Spain and Portugal, ending up at Tangier in Morocco. On the way back they landed at Gibraltar…
Quick visit to Sweden to check the house is still there and do some work on the Eindecker build.
YES! I’m finally building an aircraft. It’s an Eindecker, just like the one in Scotland. But this one is a little bit smaller.
There IS an Eindecker replica at the airfield in Sweden, it belongs to the Siljan Flying Circus and has not flown yet:
The Nieuport replica behind the Eindecker HAS flown, as part of the Flying Circus display several years ago. It’s parked up in the hangar at the moment…note the ingenious use of wooden block under one of the wheels to tilt the whole aircraft and get the wings to fit over the tail of the Eindecker, which has had its rudder removed. Both aircraft sit under the wing of Toffe’s Luscombe, which shows the dayglo markings required for flying in the “Mountainous Area” – there are other stipulations such as survival equipment but the main one is high visibility markings on the aircraft to aid Search and Rescue. Luckily the airpark is outside the mountainous area so we didn’t have to carry all the stuff on our long trip to Sweden a few years back.
One reason for the Nieuport being out of action is that the tail skid is broken. It should be an easy fix though as both aircraft have tailskids featuring an ice hockey stick as the main component!
The Eindecker I am building is much much smaller – and it is taking a long time. I got a balsa wood kit for my birthday a few years ago, and do a little work on it each time we visit:
With an average of 10 days a year spent on the kit so far, it will take just as long to complete as a full size kit!
It’s that time of the year. It’s cold outside and effin freezing in the hangar, especially when sitting still or lying on the cold concrete looking up trying to locate the source of a really slow but persistant fuel drip from a fuel tank. I have the fuel tank sealant ready for action but it needs a temperature of 20 degrees to work properly so we might wait a bit…
In the meantime the Eindecker needs a bit of work. Readers will remember when I took the old radio out and fixed the battery charging problem (a wire had come loose at the back of the ignition switch).
To do those tasks I had to take the instrument panel off. The only problem is that the mounting screws are underneath the leather trim around the cockpit, so that had to come off too. Here it is in its “unfurled” condition, with the foam padding (pipe insulation) on the starboard wing:
Workplace preparation is essential for the smooth completion of any maintenance task, it says here. So the replacement laces were laid out within easy reach ready to be installed:
Sadly I couldn’t find any “Eindecker cockpit coaming securing lace (200cm)” at Light Aero Spares or on ebay, so I grabbed several packets of the longest bootlaces I could find in Tesco and ended up tying them together as I went along.
Starting at the back left corner it was easier than I remembered:
Working round the front I noticed a problem with the throttle cable, and made a mental note to come back to that afterwards. Note the leather throttle handle, the unit itself was 3D printed by the previous owner during a refurbishment:
And finally, the completed job, looking good again:
The throttle cable mounting had come loose, which meant that the last bit of throttle movement was flexing the throttle cable rather than transmitting the movement to the butterfly in the carburettor, and with the throttle fully forward the engine would not have been producing full power. All secure and fixed now, ready for the weather to improve, the evenings to lengthen and the winds to die down a bit. Evening patrol season is coming!
Damp December. But not TOO damp – time for a little jaunt around the local area to continue to break in the new cylinder:
At the holding point. All the pilots in this shot of Scotland spoke with Irish accents:
Airborne and accelerating hard…I love the way the cruise prop on IB gets more and more efficient as the speed rises. By the time we passed Wolfhill we were steaming along at 160 knots:
The fields looked sodden and the River Tay looked rather full…
Low cloud and mist:
Dunkeld with mist patches:
A cloudy cap on the top of Birnam hill:
Lots of moisture around, and the weak winter sun shining through a high layer of thin cloud, heralding the approach of a front from the west…
A couple of days later, the frontal system has passed through, adding more moisture to the ground. Time for another flight:
A little bit more water around, the rivers had broken their banks in places
The confluence of the Isla and the Ericht rivers:
Anyway, I digress. The purpose of this whole exercise was to break in the new cylinder and piston rings, and that meant running the engine at high power, fuel economy be damned. Here we are straight and level at 2600rpm, which is about 96% of the maximum 2700. The yellow arc of the airspeed indicator is the “caution range” – this means gentle control movements and smooth air only. Most of the high speed run was done with the autopilot in for gentle control movements…
…and the winds were light so the air was smooth. 173kts groundspeed from 168kt airspeed is a 5 knot wind at altitude:
You can see from the Skydemon trace which bits were flown on the autopilot, and which were hand flown. It was a miracle that we found our way back to the airfield with all that wandering all over the countryside:
But find it we did, and it was time to try landing. There was an 8 knot crosswind at 90 degrees to the runway, blowing from the south. Now 8 knots of wind is usually not much to fret about, but coming from the south it was blowing nicely over the hangars and other assorted airfield buildings which produce turbulence. Great.
The first landing was witnessed by my new boss, who was watching from the helicopter base. As I bounced down the runway he was heard to mutter “You’d better go and start up Helimed 76″…just as I put the power on to go around and try again.
The second attempt was thwarted by a slow student in a Cessna 152, who landed long and used the whole length of the runway to stop, before backtracking and ambling back down the runway to the turnoff. The go around wasn’t spectacular, as it was easy to see the situation developing and I went around from 500ft back into the circuit for the final landing.
It was a bit bouncy but not as kangaroo-like as the last one. I remembered the advice given to me by Justin Paines, ex-RAF test pilot for the F35 Lightning programme and until recently, owner of a nice RV6…he always raised the flaps on touchdown, especially on a bumpy grass runway like his home base Compton Abbas. This has the effect of removing lift and ensuring the aircraft sits on the deck without any tendency to get airborne again. I did remember this advice, but far too late. Maybe I’ll try it next time…
As pilot we judge ourselves on our performance, and tend to dwell on crap landings. I texted Brenda to say I was down safely but did rubbish landings. Her reply?
She’s a keeper! Merry Christmas and Happy New Year to both my readers!
Cowlings back on again, for the first time in months:
Since the end of July, we had a bit of tinkering to attend to:
Sump oil leak, cylinder head cover oil leak, carburettor sent off for refurbishment, dead number 1 cylinder (new piston rings and cleaned up valves), dead battery and dodgy starter motor.
Finally everything was back together and ground runs completed. No excuse to put it off any longer. Time to fly.
A general wazz around just to the north of the airfield, keeping close in case we needed to get back in a hurry. Note the trace showing a simulated circuit pattern just over the A984 symbol…this was to check the engine response in a balked landing when full power is needed in a hurry.
All was satisfactory so it was back to the airfield for circuit practise. This was to exercise the engine through the whole range of power settings and had the added benefit of landing practise for me.
With hardly any wind the duty runway was the east west one. This goes right past the clubhouse windows. And everybody is watching (and grading) the landings. No pressure, then…especially as fellow helicopter pilot Chris (who also flies an RV3 and is building an RV14, see http://www.vansrv14.uk/) had just landed and was undoubtedly watching with the rest of the vultures.
Several landings later and the aircraft was still in one piece and capable of being taxied off the runway, so the landings can’t have been TOO bad. The RV grin is back!
As usual the landing debrief from the gallery was brutal. They take no prisoners. Not to worry, the aircraft flies again! Plus it was time for me to join the grading team and watch some landings for a bit…no pressure!
“If all goes well, it’s back into the air. Can’t wait…“
All didn’t go well. We ran the engine to set up the idle mixture on the carburettor and there was a lot of vibration. Cylinder head temperature (CHT) on number one cylinder was way down, almost as if it wasn’t firing.
Well, no “almost as if” about it. It wasn’t firing. We swapped sparkplugs around and checked ignition leads to try and isolate the fault, but it stubbornly remained.
Inspector Sandy started to suspect a stuck valve, which would be allowing the fuel/air mixture to leak away, so next step was a compression check to check how well each cylinder held its pressure…
With an input pressure of 80 psi, cylinders 2,3 and 4 were losing between 5 and 7 psi – those are pretty good compressions.
Cylinder 1 was losing 64 psi – that’s a pretty BAD compression. Obviously.
Cover off and inspection of the valve rockers revealed movement, so no stuck valve. We began to suspect worn piston rings. For this, the cylinder would have to come off. Time to get the tools out again…
A sorry looking engine. To get to this stage involved removing the inlet tube, exhaust gas temperature (EGT) probe, cylinder heat temperature (CHT) probe, exhaust, fuel prime pipe, oil return line, front baffle, lower baffle, spark plugs and ignition leads, cylinder and piston head. We found the problem.
Worn piston rings confirmed. The gaps were way oversize and had also migrated round so that all three were lined up, providing an easy wide pathway for the fuel/air mixture to just hiss away on the compression stroke, leaving nothing to ignite when the spark plugs fired…(two plugs per cylinder, it’s an aviation thing…)
New piston rings aren’t cheap…ask me how I know. While they were on order Sandy took the time to clean up the piston, cylinder and valves as they were a bit manky. All normal for an 1800 hour engine, but why not?
The piston crown before:
The same piston and one of the valves after cleanup:
We had a little trouble with the valve collets, they are the little semi-circular pieces by the spring:
So I took them over to Bob in the next hangar. We had struggled over a whole lunchtime to get them out, but Bob had them out in 10 seconds, plus another 10 seconds to put them back in a few days later…It’s amazing what the correct tool can do!
Sandy fabricated a valve ring compressor tool for getting the cylinder back on:
…and after about 10 minutes of huffing and puffing and maybe the odd swear word, we got the cylinder over the piston rings and onto the engine. Cylinder bolts tightened up to the correct torque, all I need to do now is reverse the process and get all those bits back on, then several ground runs (…including the one to set the idle mixture which we were half way through when this problem surfaced…) and a specific flight profile to get the piston rings bedded in. We’ll be flying again by Tuesday.
I’m not committing to WHICH Tuesday though. I’ve learnt my lesson.
I was going to call this “Oil’s well that ends well”, having finished rectification of the oil leak…but it didn’t end well.
There was a bit of faltering in the engine during the ground run to check for leaks, almost as if the mixture was running too rich – too much fuel starving the fuel air mixture of air.
After shut down we found fuel dripping from the air filter box under the carburettor. Time to get the tools out again.
Disconnecting the air box revealed the carb intake:
…and I lay under the aircraft with the fuel controls at different settings to see what would happen. There was a persistent drip of fuel from the “float bowl atmospheric vent”, which as the name suggests, should probably be filled with air rather than fuel. This fuel would be getting into the carb throat and richening the mixture. We decided to remove the carb completely and investigate further.
The fuel lines and control rods were disconnected and the carb removed. Note the use of tie wraps to annotate which control rod is which, red for mixture, white for throttle. It should be impossible to connect them up wrongly, but where there’s an idiot, there’s a way. The nuts are rethreaded onto the bolt threads for the same reason, to stop them getting lost.
Tie wraps are wonderful things. Taking the carb off involved several different sizes of spanner, and it would be nice to have them easily to hand when it is time to reassemble, so I tied them together rather than throwing them back in the tool box:
…and also took some notes as to which spanners are used where:
Once the carb was off I decided to send it off for an overhaul so that the experts could rectify the problem. It had done 1800 hours and was probably due for one anyway, and getting it done professionally gives added peace of mind. Here it is just after removal:
And here it is ready to dispatch. I chose Nicholson McLaren to do the work because they have a good reputation and they were the most “economic” quote! They featured in a video by Jon Hunt, see:
Just a week later and it’s back, freshly overhauled and beautifully packaged. It’s lovely and shiny, almost looks new…
It arrived back just in time for my return to work. Typical. Luckily all was not lost…there was a bit of preparation required, so I did that at work, in between flying…and who says men can’t multitask?
Next week, refitting and ground run to set up the idle mixture. Sandy the inspector is helping with that one. Sooner him than me crawling around under a running engine fiddling with an adjustment nut right next to hot exhausts.
If all goes well, it’s back into the air. Can’t wait…
Attributed to astronaut Alan B. Shepard, the first American in space. It is usually quoted as “Dear Lord, please don’t let me f**k up” – which is exactly how I felt as I started towards the engine with tools and intent. Time to investigate the oil leak.
Pretty sure it was coming from the oil sump gasket, I realised that to change the gasket would involve taking at least the four inlet tubes off, and if the sump didn’t drop far enough, the exhausts too.
The tubes came off quite easily:
But is was still a little crowded under there:
And the exhausts would have to come off. Great.
Once the exhausts were off it made it a lot easier to get at the sump bolts:
But eagle-eyed readers with a bit of Lycoming O-320 knowledge will notice that the starter motor is removed too. That sucker was preventing me getting at just one of the sump bolts. One bolt. And that starter motor is heavy. So to get at one bolt I had to undo another five bolts, four spacers and two plates. Even minor tinkering grows arms and legs.
Once I could get at the bolts it was relatively straightforward to drop the sump and remove the old gasket. You can see the new one ready to go in the photo above.
Before putting it all back together I had to order new exhaust gaskets, inlet gaskets, new hose for the warm air ducts, new exhaust bolts and washers. Once they arrived it was relatively straightforward to get it all back together. With no parts left over. Always a bonus.
Time for a ground run to check for leaks. Filled with oil and a sploosh of “Camguard” – it guards the cams, what else can I say? I started up, checked oil pressure and temperature rising, let it run for about a minute and shut down. I jumped out and had a good look around the engine. No leaks.
Then it hit me – the engine started! I didn’t f**k up putting the starter motor back on. Ole Shepard produced an effective prayer, I’ll be using it regularly.
Another run, this time for about five minutes and up to 1700rpm for an ignition check. All looked good so we shut down and put the aircraft back in the hangar.
I was tidying up the tools when I noticed this under the left side of the engine:
And it was getting bigger! Bugger. I followed the drops back up to the source and found leaks at the base of both left side cylinder head covers. Removing both revealed splits in the silcone rubber gaskets:
Definitely a route for oil to leak out. They’ll need to be replaced. Here we go off to the Light Aero Spares website again…they must love me.
New ones are on order (£7.77 each)…but I’m back at work so tinkering will have to wait for a few days.
At least the oil sump has a new gasket, whether it needed one or not…