UK Light Aircraft Association (LAA) required a minimum of 5 hrs of testing with at least 15 landings, whilst remaining within 25 miles of the designated test base. The required test plans were: See LAA website for details The Garmin G3x allows the collection of a mass of data recorded every second. This can be easily analysed in applications like CloudAhoy later, greatly helping accurate data collection and flight re-runs like this: The mandatory testing was completed over a 2-week period, 4 flights including an endurance flight of over 2 hrs to test all systems and maximum temperatures and pressures. A MAUW climb test for 5 minutes was done with an average climb rate of ~830 feet/min. All avionics worked as designed. The elevator trim tab was adjusted slightly to achieve sufficient nose-down trim at a max cruise speed 139 KIAS.
MoreAuthor: peter843
First Flight !
Second flight load up to MAUW and button up the panels.
MoreWeight and Balance
The weight of G-PTSI with fire extinguisher and spats in place came in at 524.5 kG within a few kilograms of the other UK TSIs. Thanks to Tim for coming in to make the measurements and make the required report.
MoreLots of small tasks to finish the build
Safety wiring – magnetic plug on the engine Safety wiring oil and water radiator clips Camloc retaining spring on the cowling Loctite the wing fairing screws Making the door catches run smoothly – fitting the catch covers Rigging adjustments – full range without any interference Fireproof ID plate With my Tosten CS-8 grips I needed to use the offset bushes to pull position the grips slightly back in order to avoid a clash with panel switches at full forward elevator. Steering and rudder cable adjustment Initially unable to tighten the rudder cables due to lack of range on (new longer) eyebolts. Found to be clashing with retaining rivets. I was told all Slings have the same issue. After purchasing a LH 5/16 UNF tap I was able to clean out the threads and get a full adjustment range. G3X programming gauge limits Permit to fly application paperwork Ground check on autopilot Fuel flow check Test fit of spats Attach heat shields on the undercarriage at the brakes Fuel tank calibration Initially, both fuel senders were not moving when adding fuel 🙁 After some engine starts and fuel in place for a few days, I was beginning to get sensible readings. Note that they read in the opposite sense, (RH tank resistance increases with fuel and vice versa on LH tank). Calibrated up to 40 litres per site for the moment, Rear seat catch fitting Didn’t line up, so on factory advice removed some of the backstops. Printing placards and attaching registration plate Make some engine ground runs Run-up tests. Look for leaks. Gain an understanding of the checklist and the G3x operation. Develop a checklist install in G3x and print placards.
MoreMagnetometer Calibration
I followed the on-screen tests for interference and calibration. Worst-case interference was 7% of the limit when taxi lights turned off. I did the swing test just outside the hanger and it calibrated the first time with no problem.
MoreFuel Flow Test
I did a fuel flow test. Checked both pumps and wing tanks. 20 to 22 seconds to deliver 1 litre makes > 140 litres/hr compared to max engine consumption of 43 litres/hr at take off a large margin.
MoreUpholstery
The upholstery kit was the last one to arrive. I went with standard option 1 in grey. It was the only kit without shortage or backorders! Although the required M4 rivnuts were supplied as M5, no matter easy to source. It’s quite meticulous work and I did it on some of the hottest summer days in the UK. Inside the hangar and inside the plane with spray adhesive upside down. I just took it slowly 90 min at a time. The instructions are a bit thin and sketchy and it’s was a bit of a jigsaw puzzle to work about where each bit goes and how exactly it’s designed to wrap around what and where, but I figured it out. The passenger seat runs nice and smooth but the pilot seat is a bit stiff. It seems to be squashed laterally, even after I tried to increase the width and re-rivet. Very satisfying fitting the seat and finally having a sit-down 🙂 The finished look is very classy and has that new car smell.
MoreFirst Engine Start
Checking the gauges before the first start – found that the wiring of the differential fuel pressure sensor was not correct. (Midwest colour coding of wires does not match the sensor as I had assumed!) Purged the fuel system from a 5-litre fuel can to clear any debris through the system. There was a bit well worth doing. Followed Rotax oil purge instructions. Started well on the second turn of the keys. Would probably have started the first time if I had kept the starter engaged a second longer. All gauges in the green. I made several runs. First run – 2 min stop check for leaks none found. Second run 20 seconds check turbo oil flow OK Third run 4 min oil up to > 50 C – all good no leaks
MorePlane moved from paint to hangar
A long busy day. I made two journeys from the paint shop to the final airfield. First with the fuselage and then with the wings. The wings were very carefully stacked using 6 old tyres for spacing and packing.
MorePaint
My paint scheme was inspired by the Sling USA demonstrator plane N135WT and my current group share plane GCLAC. With changes to the blue and gold paint. Aerotech Paint Ltd did ane excellent job at Thruxton airfield, 27 June 2022 to 20 July 2022. Just so I remember later the paint colours are: Blue MIPA B-5-04145.500 Gold stripe MIPA B-1-03780.500 Mouse Grey MIPA O-7-00140.500 White
MoreEmpennage Fairing
The empennage fairing did not fit too well. A large 4mm gap at the leading edge of the HS. It’s a nice snug fit on the VS, but not able to pull the fairing down to be flush with the HS. After discussing with the factory, I elected to add some flock filler along the fairing edges around the HS. (West System resin plus 403 filler). Drilling the 6mm holes in the fuselage for the rivnuts was a breathtaking moment. In the end, it all lined up very nicely. For easier inspection, I have decided to use flanged M4 hex button head bolts to fit.
MoreEyebolts – Sevice Bulletin
The factory has issued an SB 0020 on eyebolt types. Seems I have 25 out of 26 of the defective type 3 . All will need to be replaced! Spent 4 hours removing all eyebolts. The ones on the rudder pedals and inside the ailerons were harder than the others. Lucky for me I was able to do this at an early stage.
MoreCompleting the Canopy
Gas struts and door latch strike plates assembled. (I let out a few seconds of gas from the pre-charged gas struts to reduce the opening force).
MorePropellor Arrived
After 9 months my Airmaster propellor arrived. I checked all contents of the prop to be sure I have everything for later on. All were present after missing parts were found. Wired up the controller.
MoreWingtips
Wingtips were quite easy to fit. KAI is good on this one. Important to get aligned with the spar and also snug up to the leading edge. Don’t forget the nav light wiring!
MoreTaxi / Landing Light Lens
To make a more serviceable lamp lens I decided to use M3 rivnuts to attach the lens. (Rather than the kit supplied self-tappers).
MoreWindscreen
Quite a challenging task, probably the scariest in the whole project. First is to trim, trim, trim the windshield to size. The factory recommends an angle grinder. I used a Dremmel with a 38 mm grinder. Took most of a day and a lot of patience to trim the windscreen to fit exactly. There’s no going back if you trim too much! It’s a very dusty job, outside with a mask. To get the lines to trim and for the bonding itself, use good quality vinyl line tape to mask, mask, mask and get clean lines. The Sikaflex gets everywhere. Everyone says that, but until you use it you don’t really believe them. Lots of gloves lots of masking tape. Some help. There are several bottles to use. Cleaner (called activator the big bottle) Primer for GRP, Primer for the window itself. Take your time (it took us about 4 hours). Get some help (Thanks to Graham for all the tips). Get the Sikaflex evenly squished by using spacers. (It’s Important to read the Sikaflex application notes (mostly for marine applications) in addition to the Sling instructions. I am very happy with the end result.
MoreFilling the Brake System
Messy job. On advice, I feed the brake fluid from the cylinder up to the reservoir. The trick is to be sure to remove all air bubbles from the master cylinder and purge the air out. To do this it’s important to have the centre console loose so it can be moved upside down allowing the air to move to the highest point.
MoreControl panel
I sprayed the panel myself with Paragon Paints enamel Black (Night) BS381C – 642 , not too black, tried to match the black leather than go all out black black. With about 10% PT8 synthetic thinners. I am very happy with the result of the engraving done by Bay Engraving. I finished it off with 4 coats of good quality clearcoat. (Oppted for the longer lever for parking brake).
MoreAligning the flaps and ailerons
This turned out to be quite a tricky step, requiring lots of patience. It’s important that the flaps and aileron trailing edges are aligned with a (string) line from wing root to wingtip. My process. Attach rivet, clamp in place, and check alignment. Realign, rivet. I spent several days on each wing for this step. Plus some back and forth with the factory. Top tips, use duct tape to hold it in place. Use a rivet with the mandrel removed to form an easily removable rivet place holder. Take your time. In the end, the LH flap aligned with hardly any match drilling. The LH aileron required 3 attempts but went on quite well after fully clecoing it first. (including dimpled holes). The RH wing was the other way. The flaps required several attempts and in the end many of the outboard holes needed to be match drilled (no more than ¼ of a hole). The RH Aileron aligned with no match drilling. Just tolerance build-up I suppose.
MoreFuel tank testing
I tested QB fuel tanks in several ways: Baloon test – test the circumference over 24 hrs Soap test high concentration of washing up liquid – look for bubbles Manometer test – 700 mm column of water. Look for change at constant temp and atmospheric pressure All tests are tempo and pressure-dependent. Probably the manometer is the most reliable if done the same temp to the same temp over x hrs. I pressured the tank to about 700 mm (using my lungs) and watched for a change over 24 hrs. The pressure initially changes as the temperature of the air equalises. In my case, both tanks were absolutely fine no leaks whatsoever. Less impressive were the 2 rivet tails found in each tank. Anyway managed to remove them out through the filler cap. Talking of filler caps. My QB tank has a ‘feature’. The filler cap receptacle is not aligned correctly. Attaching the fuel tanks to the wings took a long time, to align and figure out how the brackets go.
MoreFlaps and Aileron assembly
My last work with Aerowave was to do the priming. Happy to disassemble the paint booth to make some space in the workshop. It’s getting quite busy with the wings in there as well now. Assembly was quite routine, and a rewarding experience. Top tip for later. Fully cleco up all skins even the ‘do not rivet’ holes to get the skin formed for easier wing alignment.
MoreRivet filling
All external rivets filled with Superfill. Thinned it down with a few drops of white spirits. Used a syringe to fill each rivet. Its a long tedious job. The underside ones are easier than you think. At least you can lye down on the job! Top tip. To avoid having to sand down each rivet later, used panel wipe and a paper towel to clean off excess filler before it sets.
MorePaint
Choosing paint. I like the paint scheme of the Sling demonstrator plane in Torrance California N135WT. It’s very similar to my existing share group plane. I have gone with slightly different colours. White Blue MIPA B-5-04145.500 Gold stripe MIPA B-1-03780.500 The rear of front seats door latch cover composite MIPA O-7-00140.500 Mouse Grey.
MoreWing Stand
I need to ready the workshop to work on the wings which are now en-route. Luckily one of my neighbours was disposing of a large pallet. And another neigbour has a rather good table saw. Also one way to repurpose all the Sling packaging wood. Plan to use the stand inside a van to transport the wings. Then add some wheels later. The stand is also useful for holding the wings whilst working on them.
MoreTest fit of empennage
Exciting moment. I wanted to see where the tail wiring connectors should be fitted. It was a sunny day so I pulled the plane out to make the first test fit. It also allowed the GTN650 to see some satellites and relocate to Europe 🙂 Later in May, I also checked the alignment of the empennage fixings and did some minor match drilling so it would be easier at the final assembly after paint.
MoreWings are on their way
My quick build wings shipped from Durban 25 March 2022. Its interesting to track the container ship. And frustrating to see how much time is lost waiting for a dock and time in port. Route Durban – Cape Town – Santa Cruz (Tenerife) – London Gateway Port.
MoreCowling
Quite tricky and time-consuming to get it right. 3 days. Decided to go with Camlocks all-around rather than Camlocks plus 4 Dzus fasteners in the lower cowling that the kit has. Some rework of fibreglass is needed. KAI is a bit unclear about exactly how many Camlocks to use on the horizontal seam. Looking at completed Slings some have 4 some have 5. I went with 5. Used a spacer at the prop hub to get the cowling in right place. Even so great care is needed in the trimming, to be sure it ends up in the right place. 3D printed a template for drilling the holes.
MoreSide panels
Closing up the side panels. Sealing the vent channel with Sikaflex.
MoreInstrument panel first switch on
An exciting moment. The G3x immediately found (over the CAN bus) the magnetometer (GNU11) and audio panel. I initially had problems recognising the transponder. Made a software update G3x V6.0 now. Then reinstalled the config file. Then it worked fine. Flaps, inside lights, boost pump. G5 all work fine. I have never used a G3x, so I spent some time getting to know the panel and adjusting the infinite number of settings! The G3x is an awesome piece of equipment. Found couple of errors in the wiring harness. The lane B LED and Lane B switch were wrong way around. Easily fixed by re pinning the CPC connector. The wiring of the IBBS 1 and 2 battery volts monitors were not made in correct locations. Rewired D connectors to set GP3 and GP4 on the GEA24 for IBBS volts. I had to remake four loose crimp connectors at the relays. Found a loose engine sensor probe which was giving an error on the G3x. All systems seem to be working fine now. (no engine start done yet) but only error is the magnetometer calibration not done.
MoreBonding the top skin
Been putting off bonding the top skin for some time. Was about to do it then realised I need to run another cable for the propellor pitch control. I don’t have the prop cables yet but left some space to hopefully easily thread it later on. When the top skin is fixed it seriously restrict access. Anyway, set to work with Sikaflex 295 UV, instructions say > 10C, so waited till the afternoon we hit about 12 C inside the workshop. The Sikaflex is messy stuff, it gets everywhere. Also messes up your clecos. Lots of acetone was used to clean them and everywhere else it got.
MoreWiring
Been laying out the wiring harness through the centre console and looking to see how all the required lines will go. Especially how all the lines will go and not clash. Getting past the elevator torque tube. It’s very busy. In the centre console are: Rudder cables x2 Antenna coax x 4 placed in grey plastic flame retardant conduit Fuel lines x 4 used a 3D printed spacer for rudder cables Rudder cable x2 Wiring harness Pitot and AOA pipes Throttle cable Brake fluid header pipe Rear connections The magnetometer has to be fitted in the rear fuselage through an inspection hatch. Quite a fiddly job to do. Brass screws with locktite without dropping a screw that will rattle forever. Then fit a zip tie on the pr existing clamp provided by the factory, so that the magnetometer cable doesn’t go near the rudder cable. 28/2/2022 Tidied up the centre console wiring and added the pitot and angle of attack lines.
MoreAntennas
15 Jan 2022 Learnt about doubler plates and installed the GPS antenna – well at least test fit till after painting. Used the Dremmel to repurpose the kit supplied mounting bracket, making a nice doubler plate for the GA35 GPS antenna on top of the fuselage. The transponder took a bit of sorting, needed to open up the floor in the centre channel to get access for the fixings. Another use for the laser level. :-). Factory said no need for a doubler plate on the transponder antenna, but I made a small one anyway. Also learnt about UNF and UNC fixings. It’s amazing the Garmin GA35 cost so much, and I still have to source 4 specialised UNC 8-32 nuts to fit it! The bolts you do get, but they are also special 120 degrees. The Rami AV74 transponder antenna comes with nuts.
MoreAutopilot Servos
I fitted the Aileron AP servo today. Should have been a quick job. But no, was a really long job…The bracket for the servo was not factory fitted (as it should have been in QB), no matter, spent a long time getting the bracket fitted. Need to get 4 off M4 nyloc nuts fitted where you cant see under the spar and in a very narrow gap. Quite hard going inside the cockpit for several hours on this one. Then the AN3 bolts to hold the servo in place very hard to get to. All done in the end but a very slow progress day. The following day fitted the elevator servo. Again a tricky job. The last AN3 bolt was very hard to tighten, had to try all sorts of combinations of my 1/4 socket extensions and adaptors in order to get a socket that fit the depth available and the small space. Found that the elevator control stop under the console and the AP overrun ring do not align even after changing control rod length. After communication with the factory, the fix is to remove some (10 mm in my case) of the Garmin control stop ring and rotate the stop ring one screw to the right.
MoreControls
Started the joystick and push rod control system, spent many hours making sure the rods run smoothly. 27/2/2022 – A note on making the controls run smoothly. The design used pushrods and torque tubes running on (?) plastic bushes which are self-lubricating. In fact, they run nice a smoothly. The challenge is that any misalignment of either torque tube (especially in the elevator controls) horizontally or vertically, a fraction of a millimetre will cause the bearings to bind and ruin the smooth flow of the controls, especially the elevator. I spent many many hours carefully aligning and removing fractions of mm from the torque tube clamps in the centre and rear. In addition, when it was all finished I found that I had not fitted the fixing collars on the front control tubes (see pic above) close enough so there was some slop in the elevator. Hey ho, take it apart again and redo it! Now it’s running beautifully, I am very happy with the result of many days’ work. I asked the factory for guidance on the pull force that’s acceptable, they are yet to get back to me.
MoreAvionics rack and wiring harness install
Got started on fitting the rack today. Doubler panel. The latest offering (Jan 2022) from MWPB splits the harness into two. One for the airframe and one for the equipment rack behind the dash. It is quite overwhelming figuring out where the tentacles of these wiring harnesses go at first. Unlike the rest of the Sling kits where you have many diagrams and the parts down to every last rivet and grommet. The MWPB panel and harness no install instructions or layout diagrams other than Facebook videos. You are also on your own sourcing any extra clams and tie wraps. Two things were needed to get started. Where do the ground and power busses mount, and which wires need to go through the firewall (so that I can get that done and fix the top skin). Once I got my bearings, it become s easier. The rack behind the dash has a sub-rack that is designed to mount an audio panel transponder and second com radio. It’s white heavy (820 g) and made from 2mm aluminium. I also was concerned about accessibility to service the audio [panel after the windscreen is fitted. I could not see how it could be removed. (Whereas the transponder can be removed with screws from below). I decided to remove the sub-rack to save weight and improve serviceability.
MoreFitting the panel to dashboard
Lots of work with the Dremmel was required on my dash to open up the fibreglass/leather. Slow messy job. There is very little space below the main switches on the left. Fitted rivnuts with epoxy glue. Used pilot countersink to get an accurate position. All line up nicely. Had to remove the leather at the end to make a good fit without warping the panel.
MoreAvionics panel has arrived
Panel arrived! Well at least package 1 of 2 after 12 days chasing customs clearance with UBS! Looks good but has some minor damage. Started assembling ECU onto LRU rack using MWPB customer videos as a guide.
MoreSeat belts
Test fitted the seat belts to see if I have all the right bits. KAI is not clear. Emailed with factory, updated the rivets to 4.8 mm on the front seat belt brackets. Torqued the belt clamp AN4 bolts to 7 Nm. Will fit the belts later when nearer completion. At least I know how they all go for now.
MoreCanopy and Doors
I have QB with canopy factory installed. However, there is still some tricky work to do on the door composites, so I removed them to work on. The main door latch mechanism has a complex shape composite fibreglass cover over it. This needs to be cut and machined to fit the door lever and latches. It’s a firm snap-on fit plus two M4 rivnuts. It took quite a bit of work (2 hours per door) with the Dremmel and filing the mouldings to get a nice fit. Worth spending some time on. It’s very visible and used every flight. I also adjusted the latch mechanism to run smoothly and then added some medium strength Loctite to the connecting rod and latch pivot nut. The KAI shows an optional adjustment hole for the two main pivot points (to enable tightening them up if they become loose). Having seen how tricky it is to get this moulding on and off, I don’t want to have to reopen it after it’s painted, for sure it will get very scratched. So I added the adjustment holes. Following info in case, I need to remove the mouldings in future. Here’s the way I did it. Remove 2 x M4 button head screws, then. Bent the strike plates per instructions. Not clear why they are labelled right and left they seem identical. KAI says shiny side inwards, but my plates were identical on both sides.
MoreStatic Ports
The factory has moved the static ports to 25 mm in front of the Nacca duct. (Used to be in the rear fuselage). The ports now require a shield to be riveted around them. A kit is on its way to me. Although not essential, I wanted to get the ports installed before the top skin is fixed as it’s easier. Unfortunately the rear of the static port clashes with the Nacca duct, so I machined a little of the Nacca duct away and filed the static port to fit.
MoreInstalling the top skin
Using Evan Byne video guidance affixed the top skin. The composite seemed to need twisting a little to get it to fit evenly on both sides. Using the hole finder tool, the trick is to align the firewall flanges to be flush with the front of the top skin. Then drill the composite. Made a test fit of the dashboard. Not a bad fit but some gaps on top left side. Sourcing a suitable 120-degree pilot/countersink tool for the top skin (and empennage) composite proved tricky in the UK. I found one from a company on the south coast (BSA Regal Cutting Tools) that made one up to the size I needed. 1/8 inch pilot with 5/16 head (3.2 mm x 7.9 mm) that should suit the 3.2 and 4mm countersunk rivets. KAI calls for painting the composite black.
MoreGetting ready for closing front composite
The arrival of my avionics panel is imminent and I will need to fit the LRU rack. To do so ideally the front composite needs to be in place to secure the avionics first rib. With the front composite and LRU in place, access to the heater, fuel pipes and rudder pedals will be difficult. So finished off the rudder pedal riveting to the floor and pedal rivet, ensuring free movement in the plastic bushes (I had earlier filed the lock plates and bushes for a smooth movement). Rudder pedal assembly install is quite difficult in a QB, as you have poor access. Attached the rudder cables and steering pushrods. Torqued nyloc nuts AN3 to 3 Nm and AN4 to 8 Nm and marked. Fitted booster pump. Assembled so that it can be removed with its attached hoses and check valve as one. Likely the SAE R9 fuel hose will need replacement when needed on condition in 5 to 10 years time. Fitted heater temperature control wire. (removed 200 mm from the 1m Bowden tube). Per Evans video. Fitted heating hose, ensured hose clamps well seated. Would be fiddly to fix later. I am using the large ‘Rotax’ firewall hole for all electrical connections. Because the large Rotax connectors have to pass through, there’s a large hole to be filled. I remade the kit ‘horse shoe’ plates to a smaller diameter (34 mm to close up the hole. The remaining gaps to be filled with high temp RTV.
MoreHorizontal Stabiliser
Extra countersinking in the forward spar is needed in my case, to accommodate the 8 extra dimples I made in the skin (top surface only). Many do not rivet locations. I needed to take great care to rivet. Awaiting for my main spar so paused for the moment. 5 Feb 2022 missing empennage parts arrived so I could finish the skeleton with Andrew’s assistance. Wed 9th Feb 2022 Spent a lot of time with laser level getting the HS absolutely straight (no twist). Level the table to start with. Various advice from other builders. partially cleco one side, level, then cleco the other side. Add more clecoes, check, turn, check, check again. Rivet from the centre outwards along the main spars, check, check, check all the way. Seems to be very hard to do accurately without a laser level. (9 hrs to do the HS alignment and skinning, but I am very happy with the result.
MoreElevator
Started elevator, the instructions and Evans video are very clear. Note the 2 stainless steel rivets. Different rivet size on end ribs. 10 Feb 2022 Having got the HS absolutely straight proceeded with the elevator skins. Important notes. There are two floating ribs that need to be inserted the right way around. There are small pieces to strengthen the trim tab hinge. Smaller 6mm rivets are needed just on the right side at the thinnest point. The elevator composite tip on the right needed to be worked up with extra fibreglass. Add the trim servo inspection hatch mounting ring inside the elevator before skinning! Test fit to HS to check hinge alignment and elevator deflection. One hinge is is a bit stiff. Hard to attach on the bench. This will be hard with unsupported HS and Elevator. Deflection seems to be good and within specification in the POH (+30 Degrees). Earlier builders report having to remove some of the HS skin to achieve the required deflection.
MoreVertical Stabiliser
The vertical stabiliser has some points to watch. Important to open up the M4 holes in the lower part of the vertical spar. Use some bolts to be sure they freely fit later on. I opened them up to 5 mm. The rivnuts are by design I think held behind the vertical channels. Looks a bit strange, but all holes do align and it seems that Evans Sling official build video advocates this assembly. (Rather than drilling clearance holes for the rivnut flange heads. (This may weaken the effectiveness of the rivnut). I set aside for the moment as I am missing rib 1. 26 Jan 2022 Avionics package arrived from the USA, did a fit of the RAMI 525 VOR antenna, carefully filing out the holes per KAI. With the grommets in place, it’s a tight fit. A bit of a bulge, let’s see how it goes with the skins. Note that the pins on the top of the antenna are connected to the antenna elements and could easily short over time with the doubler plate. I filed them flush and added some Teflon tape. 8 Feb 2022 LAA inspector signed off the empennage skeletons, so started skin riveting with the vertical stabiliser.
MoreRudder
Assembled the rudder today. Pretty straightforward. Printed KAI has the wrong rivet size of 3.2 mm rather than 4 mm in one place. The latest dropbox KAI is correct. Took some time and care to get the composite rudder top to fit nicely. Did a dry fit of the skin, aligns perfectly. Will await inspection before riveting up. Glued some aluminium M3 washers to the inside of the composite rudder cap. Checked alignment and hinges on VS. Plenty of deflection 20 degrees required almost 40 available before clashing with VOR antenna.
MorePriming
Did my first real priming today. My earlier test on the internal panels didn’t turn out too well. Streaky and poor coverage. Too cold and me never used an air spray gun before! Anyway, after a bit of learning on YouTube and an understanding of gun adjustments. I did some tests on the packing crate wood, I started on the real parts. Rudder and vertical stabiliser. It’s December and the outside temperature is 4 C, Aerowave 2001 the two-part primer I am using requires at least 15C and less than 80% humidity. I heated up the booth to 15C and carefully started. Took about an hour and 300 ml of Aerowave to do the first parts. Used a small HVLP gun at 29 PSI with a 1 mm nozzle and works quite well once I got the hang of the adjustments. For the second run of priming, I used 400 mL of Aerowave for the larger parts of the HS and elevator including skins internal surfaces only.
MoreLet the dimpling begin
The empennage kit finally arrived (rudder, vertical stabiliser, horizontal stabiliser and elevator). Although some major parts missing, like the main spar! Anyway started by unpacking and removing plastic coverings. A good tip is to use a heat gun on the larger skin areas. It’s quite hard to remove the plastics in a cold workshop in December. Sort parts to main subunits – rudder, vertical stabiliser, horizontal stabiliser and elevator. Then to deburring mostly with a large drill bit or a small cordless drill with a countersink bit, a steel rule and a deburring tool for the larger holes. Purple Scotchbrite to finish off deburring. 2 days prep and deburring all parts of the empennage. Then my first dimpling. Having never done dimpling before, I read up around the topic. Philip Rueker’s blog has some good info. Important to note that Sling uses 120-degree dimple dies (not more standard 100 degrees). Two sizes of dimple dies are included in the kit. (Although since the materials are quite thin, the same size die is used for both skin and rib). The introduction KAI instructs that the holes to be dimpled are smaller (2.8 mm) and match drilled to 3.1 mm before a countersunk rivet is used. (I placed the Sling dies in my hand dimple tool). Andy kindly lent me his DRDT2. As my project is a quick build, I think I only have the empennage skins and possibly the aileron skins to dimple with the DRDT2. The rest of the ribs can be done with a hand dimple tool. The next step is to purple Scotchbright all internal surfaces, degrease and spray with Aerowave.
MorePaint booth and PPE
There’s a lot of debate about corrosion protection. As I have a quick build kit many of the parts are already treated with Alodine at the factory. However, for the empennage flaps and ailerons, I am on my own. After a lot of studies, I decided since I live on a rainy island in the Atlantic, that I needed to do something. Elected to use Aerowave 2001 primer. It’s not intended for general public use, so spent a lot of time studying the safety sheet and also learning about respirator types and specifications. I needed some decent personal protective equipment. The main one being a good full-face respirator with the correct filters. That is both a vapour filter (for the VOC’s) and a very fine dust filter for paint droplets. So an A2 for VOC’s plus a P3 filter, also known as (EN149) FFP3 or N99 in USA. (Note P2 or FFP2 (Europe) or N95 (USA) or KN95 (China) are lower specification and not suitable). I used a full face respirator to give sufficient Assigned Protection Factor. Went with a 3M 6000 series respirator. Not wanting to risk my exposure to chromates to a fake mask or filters. Also used a full paper suit and a good (Vevor 200 mm) extractor fan with 10m of hose to poke out of the window.
MoreSpats
Instructions are quite clear. My composites were not pre-drilled. The right-hand side spat fitted very nicely. The left-hand moulding appears to be different. The shorter ‘neck’ and support panel has less depth. A lot of fettling is required to get a good fit. Needed to take 5 mm off the neck of LH main wheel spat. Need to be very careful not to cross-thread the bolts in the rivnuts. They would be a real pain to replace! Used a homemade hole finder to align the front spat fixing holes and tow clamp holes. Used mobile phone on the floor to see into the spat, this was an enormous help.
MoreAlodining Small Parts
My quick build fuselage is largely already alodinded by the factory. Many additional parts to add to the fuselage that are untreated. Have decided to treat them with brush Bonderite M-CR ALCRM 1200. (Hard to get Alodine 1201 bath dip version). So that there is some consistency of treatment. My target is to treat any critical parts and those exposed to the elements, such as torque tube clamps and inspection panels. Pre-treated with Deoxidine 624 phosphoric acid. Applied the 1200 for 10 min. Even so, the colour didn’t turn out very deep, probably a bit too cold in the workshop. Like many fellow builders in the UK at present, the empennage will use Aerowave treatment and spray the components.
MoreInternal sound insulation
My kit had extra firewall foam in it, so I used it to add additional sound insulation to the fuselage. So now 3 layers of foam in places. Repurposed some of the packing crates to make inside seats in readiness for spending a lot of time on the control tubes!
MoreEngine Pipework
Having got the engine in place proceeded with oil, fuel and water hoses. The AN oil fittings are a very tight fit. Needed to heat up the oil pipe with a heat gun, add some light lithium grease, and support in a vice, to get them to fit all the way. Tightening the oil line AN fittings on the RHS sump of the engine is very tricky, only able to turn a small amount at a time. The nut on the LHS needs the silencer to be partially removed. Need to be careful not to overtighten aluminium fittings. Needs finger tight plus a 1/4 turn. Fuel hoses require heat shield silicone orange heatshield tricky to fit – used car tyre compressor to inflate – helps but still hard work to get proper fit. I noted that TAF has recently changed the fuel pressure sensor in the latest KAI. Note that 3/8″ SAE R9 fuel hose is specified throughout now for modern fuels. Need to get some R9 as my kit is missing a lot of fuel pipe. It’s easier to add the silver heat shield to oil and water pipes before the final install. The kit calls up plastic zip ties to hold hose standoffs in place. Having used these ties for many years in ham radio operations, I know that they perish easily even just outdoors, so I used some stainless steel ones. Throttle cable, be sure to use the correct PVC heat shield/stiffener hose. On each end of the throttle cable. No pre-drilled hole in my firewall for the throttle cable drilled a hole from photos. Fitted the brake hose, here is a picture of my standoff. Pictures in KAI are not clear on how to do this. KAI calls for a cut of the Rotax 915 exhaust pipe and fit a tailpipe. I made the cut with an angle grinder, but my tailpipe did not fit correctly. The expanded open end was not expanded far enough, to enable me to get the two exhaust clamps on. Plus there would be a leak at the join. The factory sent me a corrected tailpipe, no problem to fit with clamps now in the correct places. A few hours of trying to get it to fit was frustrating.
MoreFirewall Forward and engine
Prepared Firewall for engine mounting. Conscious that I needed to get as much as possible fitted and holes drilled before the engine gets in the way! Fitting the foam and firewall components was fairly straightforward. Provisioned 2 x M4 rivnuts and a space for the Midwest Panel fuse box that will be needed later. Some got ya’s along the way. The fuel return lines now go on the left of the firewall. The installation manual shows 3 holes on right but my plane only had 2. The fuel pump power connector needs to be extended, but which one, which one is main and which one is aux. Which is A and B? It seems that the top pump on the Rotax pump box (when mounted upside down) is the main A pump and the lower is Aux Pump B, so pump B line needs extending with high temp cable. I used double heat shrink and staggered the connections, then added some harness weave on top to match the rest of the harness. Useful to get the heavy electrical cables (4 – 6 AWG) installed or at least ready before engine mount. Add cable to the starter motor and engine block ground lead. Rented an engine hoist, all went fine until the last nut! Some points to note, that may help others who follow later. Rubber mounting bushes are a tight fit. (Note two different types – hard and soft rubber). They need to sit well down in the engine mount, Fairy liquid helps. Do this first otherwise, you will think like I did that the bolts are too short. (Bottom 2 bolts need to be cut to 122 mm to avoid interference with engine). (2 hrs of unnecessary work). Bottom right fixing at turbo. My engine, as shipped had a captive metric fine thread nut riveted on a plate for shipping (pic). Spent ages trying to bolt my metric coarse thread to it!! Needed to remove it (drill out rivet – hard to get to) and use the correct kit M10 nyloc nuts. Even so, it’s hard to torque up the bottom right bolt. After the engine was mounted proceeded with some plumbing. Intercooler – placing baffle and hose cutting straightforward. The baffle fibreglass mounting holes need drilling out to about 20 mm for the grommets.
MoreCentre Fuselage and Seats
First tasks, checking inventory for the quick build fuselage, firewall forward and canopy kits many items missing. The elevator torque tube was very stiff as assembled by the factory. Had to drill out rivets and file down and realign all 4 bushes. A few special tools are needed to drill around corners in a tight space! 5 hours. But hopefully will pay dividends in smooth flight controls later. Adding rivnuts to the inside centre console. Getting good at this now. Having a bigger rivnut puller certainly helps when it can get into the space. Fitted rudder springs mid-fuselage – tricky leaning through the luggage door. Assembled Rudder pedals assembled and clecoed in place for now. Centre console box. Throttle/brake quadrant. All seats assembled (more than >>500 rivets right there) . Front seats backs spray painted with 2K aerosol (RAL 7005 Matt). Lets see if it’s hard wearing enough. Booster pump – learnt about differnt NPT fittings and torquing them. Hand tight + 1.3 turns typically. Dry fit heater and tubes. Naca ducts and fresh air assembly clecoded. Challenging to fit factory assembled elevator rod, eventually did per assembly instructions. From rear with some force and grease through the mid-fuselage grommet! Some have said that the fresh air mixer rattles and doesn’t close completely, so as it’s easy to do at this stage I added some 2 mm craft foam as others have done. Glued down with Gorilla glue.
MoreThe Journey Begins
7 Oct 2021 first delivery My Sling TSI quick build kit first delivery. Although as I found out later, there were many missing pieces in the kit at this stage. Thanks to Bill for helping to unload the kit.
MoreWorkshop
The Sling Tsi is about 7m long. Luckily this fits diagonally in my existing 5.5 x 5.5m double garage. Although there’s not enough height for the tail. The cars will stay on the drive for a while. Prior to taking delivery, I upgraded my garage. Some secondhand fluorescent lights from eBay were upgraded to 4000K light temperature tubes, some recycled PVC tiles to keep my feet warm in the winter. Built a bench with wheels and bought some tools, the most important being the Milwaukee rivet gun and lots of clecoes!
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