BH Mosquito

[Hangarqueen]

This is my very first thread here on this forum (there were some technical difficulties in getting my account active...).

As a long-time Mossie fan (I built my first Airfix 1/72 kit around 1972...), I'm hoping to find others with the same pathology here.

I have flown a Freewing foamie Mosquito for several years, but that one was decommissioned last summer, the airframe having become so worn down that it flexed in every axis.  During its last flight, it was all over the sky, getting harder and harder to control.

I have been looking for a replacement for a long time already, having considered

• building a BT or Tony Nyhuis kit, but I'm afraid to lack the building skills and the patience to bring this project to a satisfactory ending
• the Seagull kit looks pretty nice, decent size, but what I read about them regarding flight characteristics has put me off

I read good things about the Black Horse kit in terms of flight characteristics, but that kit first put me off because of the many scale deviations.  It has been around for quite a while, and was discontinued long ago, so that didn't seem like an alternative for a while.

Until I found a NIB kit in October of last year, for a very decent price (120 Euro if I remember well).  The guy was renovating his house, and he had a lot of unbuilt kits  that got in his way.  Very nice chap, living in the south of the country (Belgium), who even invited me to visit his club.  On top of that, he was the first not to mention how surprised he was that women can fly too ?

Once back home, I couldn't resist doing a quick assembly to admire my newest member of the fleet.

 

First impressions:

• Very light model, it will be easy to keep this well under 4 kg.
• As we only fly electric in our club, I will be equipping this with a 900kV motor and 3-bladed 11x7 prop on 4S.  On paper, that would be 800W per side, but in reality it came out at less than 600W per side
• the original landing gear is something of a very bad joke: a mechanical retract (not bad per se) and 2 long shiny metal gear struts that retract through a small slit in the nacelles.  For its time, that was probably more than decent, but retracts have really become the new normal today.  So that will be modified for sure.
• The covering is shiny.  Very shiny.  Sooner or later, that will have to be changed somehow.

The model has had its maiden flight last week, pretty uneventful except for one bent landing gear (more on that later).
I have done a couple of modifications during last winter to the main landing gear and making the tail wheel retractable, and I bought a set of scale canopies and nose cones from Sarik in the UK. I will first do some more flights with it, before I do any more modifications.

[Zflyer]

Welcome aboard.

If you want to get ready of shiny and have the finish look a little weather beaten there is a product called elbow grease. I used it to clean the oil etc of my ic planes. Now used diluted, as it also removes some of the surface colouring. Might be worth a go and what you don't use gets used for its original purpose. So no money wasted.

[David Davis]

There are female pilots. This one is currently in training having been promoted from aircraft mechanic!

 

 

[Hangarqueen]

Thank you.

Funny that it is called "elbow grease" ?

I will most certainly have a look at this one, could be useful for other models too.

Forgot to mention that when my 88-year old mother was here when I had first purchased and assembled the model.  When she looked at it, her eyes shined and opened up wide when she said "Mosquito!".  She saw them in action during the war, living close to our first airport in Haren, near Brussels.  She knows here Spitfires, Hurricanes and Mosquitos.

[J D 8]

Hello and welcome, the plastic type kitchen pad can with care take the shine off. Try on a least noticeable part.

[Hangarqueen]

My first challenge on this model was about the main landing gear.  As it was designed for a mechanical retract and a single wire strut, it would take more than just replacing it with a servoless retract.

I did look at the Brian Taylor plans and kits, but that mechanism, although very scale, would be almost impossible to fit in this model.

In my very naive state of mind, I first tried to fit the gear from the Freewing kit, but that just looke plain silly:

It was just too small in any way you look at it.

Studying some photos from the real thing, I came to a 3,5"" wheel to be closest to scale.  Adding 2 shock absorbing struts and temporarily attaching them to a wooden cross-brace, it looked really nice:

It was immediately apparent that this construction, as it was then, was hopelessly lacking rigidity, and was going to twist and turn on every occasion.

Adding a second brace solved that problem

Doing a bit of trial and error, I got to the correct dimensions and made a new brace set from leftover Aluminum profiles, connected to the retract through a 5mm steel pin:

That pin would prove to be too thin during the maiden landing.  But it sure did look good when the model was first on its new feet:

 

[Hangarqueen]

39 minutes ago, J D 8 said:

Hello and welcome, the plastic type kitchen pad can with care take the shine off. Try on a least noticeable part.

I will surely try that too!

[Hangarqueen]

59 minutes ago, David Davis said:

There are female pilots. This one is currently in training having been promoted from aircraft mechanic!

 

 

We'll be the 21st century ATA ?

 

[Hangarqueen]

Fitting electric retracts and new gear struts is one thing, fitting the wheel into the nacelle and having functional gear doors is another thing.

Just for reference, this is how the original model was supposed to look like in 2007:

First, the gear doors.

When you look at the full scale aircraft, the doors look really curved at the top.  But in reality, the "cut" into the nacelle is more or less a straight line.

After some measuring on photos, I started planning the cutout of the doors from the thick fiberglass nacelles.  I placed a sharp marker pen on a stack of books, then moved the nacelles across to draw a straight line.  I first applied masking tape to the nacelle, to allow for mistakes in drawing to be corrected or erased.

I had to take the width of the complete landing gear assembly into account too, as it has to clear the nacelle opening when lowering or retracting the gear.

I did my best to follow the contours as they can be seen in photos of the original.  As can be seen in the picture above, the original panel lines were designed for the cutouts of the non-scale landing gear struts.  I will have to correct that later.

Next challenge was how to cut through this very thick fiberglass.  I opted for a sharp hobby knife, and started carving again and again, until I got through

One side done, repeat for other door (and later for other nacelle)

To my relief, I could then see that the landing gear could comfortably clear the opening

And we have 2 landing gear doors

And then it was time to check the positioning of the lowered landing gear.  Perfect.

Next problem was to fit the 3,5" wheel inside the nacelle when retracted.

With a 85° retract, this is a problem:

- to avoid the dreaded nose-over during taxi and landing, the gear has to be raked sufficiently forward, to move the wheel sufficiently forward of the CoG

- when retracted, the wheel has to go into the wheel well, such that the gear door can close.

In this model, unfortunately, a 3,5" wheel doesn't fit inside.  I could make an opening into the wing planking to get the wheel to go deeper, but then my forward raking is ruined.

Because I didn't have a 90° retract available (which would have solved this problem), I decided to temporarily modify the nacelle, until I find a definitive solution.

First of all, the fitting of the nacelle to the wing isn't perfect to begin with

That fact made me feel a little bit better about the next modification, which isn't really aesthetically pleasing either.  I decided to add a small inside "wall" that lifts the nacelle a bit higher from the wing, giving more room for the wheel inside.

While manipulating the nacelles for this modification, I noticed that the front rim had become so small and tiny that it broke.  I used epoxy and wooden strips to reinforce this

To mount the nacelles to the wing, epoxy "hooks" were provided, which slide into slits in the wing planking.

I had t glue these hooks to my added "wall"

And to my relief, the wheels now fit inside these modified nacelles

For the time being, I will leave the doors out for the first flights; they would only complicate matters.

But again, I couldn't resist taping them temporarily in place for a photo

That was a small motivation boost ?

 

[Eric Robson]

Hi Hangarqueen,  

The original wheels do look totally wrong but they are a compromise to get a working undercarriage without complications and once retracted they are out of sight, most of the time the model is kept in a shed or similar. 

However you are doing a great job on the undercarriage but you should consider putting coils in the legs as these take a lot of the landing shock. On the forum I have a Northrop Black Widow which is 12 lb in weight and it  had an oleo sprung nose leg, The first landing bent the pin back, it was a good landing on the main wheels but the pin which goes into the electric retract unit was only mild steel. I replaced this with a pin of spring steel and it pulled the mounting off, this was reinforced and the oleo was replaced with a leg with a double coil in it, end of problem, I also had to do the same on a Ju 88 that I built from a Warbirds Replicas kit.

I do fly from a grass strip and it may be better if landing on tarmac as I did years ago when living in another part of the country. long approaches and gentle touchdowns where as now it is a steep approach and fast landing.

Good luck with the modification it is a big improvement.

 

[Hangarqueen]

Thanks Eric.

I did consider your solution, but I didn't find a way to attach my struts construction to the spring oleo pin unfortunately.  I have only limited equipment and skills for metalworks ?

This is how badly the pin was bent after the first not-so-perfect landing:

After a good pint and then some thinking, I thought of a way to strengthen this construction, by making an Aluminum block with a 5mm hole in it that will surround this pin

It should be able to take the forces of my landings

The downside of this solution is that when I tighten the nut at the top, I pull the pin out of the retract (only held in place with two grub/hex screws)

I tried to make a sharper flat spot on the pin, but that didn't really help enough.

I did manage to do a second flight yesterday, and the good news is that the pin didn't bend anymore (landing was better too), but what I dreaded happened: the whole thing came out of the retract, after just 1 landing.  I just couldn't tighten it enough.

What I came up with, is to use a second nut, at the other side of the cross-brace of the landing gear, and make a cutout in the Aluminum block for this second nut

Now I can really tighten the top nut and have a rigid assembly.

It's not an ideal solution, but I hope it will do for the coming months, so I can fly this thing before thinking of a more permanent solution.

 

[kc]

Hangerqueen, perhaps you should try to get your mother to record for posterity what she remembers of WW2.      I have just watched an episode of the 1970's TV series Secret Army ( on Talking Pictures channel -repeated again this afternoon ) which had a ( fictional? ) story of a Mosquito attacking Gestapo HQ in Brussels before the end of WW2.   This is probably the best episode of a great series.  Worth watching to realise what happened to the population in that era and of course to understand what is no doubt happening elsewhere in the world right now.

[Hangarqueen]

38 minutes ago, kc said:

Hangerqueen, perhaps you should try to get your mother to record for posterity what she remembers of WW2.      I have just watched an episode of the 1970's TV series Secret Army ( on Talking Pictures channel -repeated again this afternoon ) which had a ( fictional? ) story of a Mosquito attacking Gestapo HQ in Brussels before the end of WW2.   This is probably the best episode of a great series.  Worth watching to realise what happened to the population in that era and of course to understand what is no doubt happening elsewhere in the world right now.

 

I have tried many times to get her to tell us more, but I think she'd rather forget than remember.  A couple of years ago, all of a sudden she started talking about the dead bodies that she saw in her childhood village, but quickly changed the subject after digging up those memories.
On the first of January, we always visit my uncle, godfather, her brother.  After all these years, he too started talking casually about how their uncles (whom I knew very well, as very kind and always smiling and humorous) were in the armed resistance, the white brigades and the partisan army in Belgium.  How they were hiding members of the resistance on their farm, how the gestapo knew that something was going on there and paid them a visit form time to time.  At one time, a letter about my family from a collaborator was on its way to the gestapo HQ in Brussels, but this was intercepted by the resistance.  Otherwise, I wouldn't even have been born, he said.

This was all very upsetting to me, a bit shocking, the fact that I never knew about this.  In my early childhood, I saw them throwing guns and weapons into a concrete floor that they were pouring for new stables.  He could even confirm that memory!  I always doubted the accuracy of that memory, but appeared to be correct.
After that, we were joking about what we would ever find in that house when our uncle passes away, that we would need the bomb squad or something.
I started reading up on the resistance in Belgium, and I actually found the name of one of his uncles in the list.

So I have developed a new strong interest in what happened in those horrible years, and especially how some people stand up and do what they believe is right, even if it could cost them their lives.  Like the small group of resistance fighters that stopped a freight train in Boortmeerbeek, causing some of the deportees (towards the concentration camps) to escape.  That was very close to my home town. 
Very casually, wile enjoying some coffee and cake, you hear these stories for the first time in your life, and you go home in silence, trying to process all this new information about people that you thought you knew.  Trying to imagine that cheerful uncle, from whom I used to get our milk from his cow farm, bearing arms.  He never said any word about the war, ever.  And now he's long gone, along with his tales and stories.

 

[Hangarqueen]

The tail section of this model posed maybe the highest challenge.

As it was originally conceived, the rudder was directly connected to the steerable (but not retractable) tail wheel.  In the photo of the original, a couple of posts back, you can see how much non-scale this tail wheel really was supposed to be.

On top of that, rudder and tail wheel had to be connected rigidly together, after which the whole tail section had to be glued permanently together.  I didn't like that at all.

I wanted a more scale looking tail wheel, steerable and retractable.  And all of that would have to fit into this very confined space of the bottom tail cone:

To the left, an opening is provided for the rudder control horn, which should protrude outside of the fuselage.  Another no for me.

I had a good look at the Brian Taylor Mosquito builds, but that construction would never fit into this space.  So I had to be creative myself.

Since a solid steel steering rod was already installed for the rudder operation, I decided to use that one for the tail wheel retraction.  As it would get quite a beating during taxi, this steel rod was really necessary to take that sort of load.

I first made a prototype of a hinged wheel support that hinges at the bottom of the fuselage, and carries the tail wheel steering.  The steel rod then connects to rotate this support plate (Aluminum profile)

I bent a wire for the tail wheel, to get a first impression of wheel position in both retracted and extended status

It would rotate through a collar on the support:

Care had to be taken though that it would be able to pass through the opening in the bottom of the tail cone, knowing that it is possible that the tail wheel isn't centered at the moment of retraction

It passes, but the opening will need some modification.

Next problem was the steering arm for the tail wheel.  After some rummaging in my spares box, I found some older Futaba servo arms that fit just perfectly.  I glued in a 6mm collar with a 4mm set screw, which in turn prevents the collar from rotating inside the servo arm

To improve the scale looks of my tail wheel assembly, I carved out a balsa "fork" in which the bent steel wire will be sunk.

For strength, I added a 1,5mm epoxy plate of the same size, which will also cover and hide the steel wire inside

I drilled some lightening holes into the Aluminum support plate and widened the opening in the tail cone bottom

I still had to carve off the edges of my tail wheel fork and fine tune the opening in the tail cone to allow the tail wheel assembly to move left and right with "weight on wheel" (which pushed the assembly a bit into the tail cone).

It isn't really scale, but better than the original

The actual tail wheel steering is done through a pull-pull cable system, which will automatically untighten when the tail wheel is retracted.

This system seems to perform remarkably well, although with some play.  But that play isn't a real problem, as this is only used for taxi.

It sounds easy when I describe it, but all in all this took me several weeks of trial and error and re-thinking.

 

[Mike Blandford]

Even with a steerable tailwheel my BH mosquito was difficult to steer while taxiing (with larger wheels than in the kit as well). Because there is little airflow over the rudder, it isn't in the prop wash of either motor, I use separate channels for the two motors and have asymmetric thrust configured, enabled by a switch, so that while taxiing moving the rudder channel causes the motor on the inside of the required turn to slow down. Now it is very easy to turn on the ground.

 

Mike

[Hangarqueen]

39 minutes ago, Mike Blandford said:

Even with a steerable tailwheel my BH mosquito was difficult to steer while taxiing (with larger wheels than in the kit as well). Because there is little airflow over the rudder, it isn't in the prop wash of either motor, I use separate channels for the two motors and have asymmetric thrust configured, enabled by a switch, so that while taxiing moving the rudder channel causes the motor on the inside of the required turn to slow down. Now it is very easy to turn on the ground.

 

Mike

Absolutely, Mike.  Differential thrust works really well, I use it for a couple of models too that don't have any steering through a wheel.

I was kind of amazed by the fact that this tail wheel construction actually works during taxi ?

Maybe because it sags a little with the weight on it?  The real Mosquito tail wheel sits more vertically, which might make it less effective.  From what I read about the real one, its tail wheel steering wasn't really effective (or even freely rotating, I think they had to use differential brakes for steering).

As I was just doing some adjusting on the rudder and elevator neutral positions, I noticed something wrong with the tail wheel.  I used a plastic hinge (I thought it was robust, but apparently not), and that seems to have been broken.  I have a metal piano hinge lying around, I will be replacing the broken one with that one.  It's a fiddly job that will have to wait until tomorrow, I'm afraid.  Weather's bad for the rest of the week anyway, so I have time.

Edited April 19, 2022 by Hangarqueen
correction

[Hangarqueen]

Adding the tail wheel steering complicated matters for the rudder control.  No way that I could cram in another steering arm.

The only solution left was to install the rudder servo into the vertical stabilizer.

First I took a scrap piece of brass, cut it to size, drilled holes in it, then soldered a collar to it

This collar then accepts the steel wire that is attached to the rudder.

I then bent a steel wire and cut it to size, giving me a snug fitting rudder control system:

To the left is the rudder servo, sitting inside the vertical stab.  To the right, my control horn attached to the rudder hinge line.

The part of this build that took me the most time probably, was how to install the tail section with the horizontal stab, and how to make this removable.
The forward part has some sort of lip that inserts to the fuselage (left on the picture above)

. This lip really needs to be reinforced, it really doesn't feel very strong. This is the easy part.
After a lot of consideration, I opted for the following solution: insert a 3mm plywood wedge with a blind nut, which accepts a 4mm nylon bolt that goes straight through the tail section and the horizontal stab:

The top of the (sunken) nylon bolt can be perfectly covered later

The rest of this construction is perfectly accessible from the bottom

Tail section done.  For now.

[Hangarqueen]

Next up were the flaps.  Originally, a servo would be mounted on the bottom of the wing (intrados), connected to the inner flap.  The inner flap would be connected to thbe outer flap via a thick steel bent wire.  There is nothing wrong with that, except for the visual aspect.  Which is even negligible.  But I wanted to change it anyway.  Too much time.

As there is plenty of room in the nacelles, I wanted to move the flap servo inside the nacelle, and control both flaps from there.  Only problem was: where to mount the control horn on?

I first did a small experiment, by using a wooden dowel to connect both flaps, ad then somehow mount a control horn on the wooden dowel

The control horn appeared to need a very awkward angle on the dowel to get a straight connection to the servo.

I then decided to make a slit into the dowel, in which I could then insert a plywood plate, which would then in turn be glued inside the flap leading edge.

This will ensure a solid connection between the dowel and the flap itself, considering the serious aerodynamic forces to be expected.

And then the servo could be connected.

And then finall, everything could be positioned and glued into place.

To be honest, this solution leaves more play on the flaps than I anticipated.  If I were to do this again, I would provide more of a guide for the wooden dowel.

[Hangarqueen]

Forgot to mention a couple of things.

This is how the hinge of the tail wheel assembly broke, near the hinge axis

I am currently replacing this with a metal hinge that I bought today in the local hardware store.

And while the tail section was open, I took a picture of the reinforcement that I did for the "lip" at the front of the top part, by adding a plywood rectangle on top of the lip, and enlarging the opening in the fuselage part, to accept this plywood part.

As the tail section will get its share of forces, I can't take any risk here.

[Graham Davies 3]

Enjoying your work HQ...

[Hangarqueen]

Assembling the model at the field should go as easy and predictable as possible.

Each wing contains 2 servos (aileron and flaps), an ESC and a retract. I decided to combine these 4 channels into an 8pin MPX connector for each side.

Normally I would solder a male connector to one wing and a female on to the other, to prevent mistakes in connecting them at the field.  But in this case, I mounted the male connectors to a thin plywood plate that would be then fixed inside the fuselage.

The spaghetti of wires that will be hidden:

After the fixing of the plywood support plate into the fuselage, things look a lot neater:

Impossible to make mistakes at the field now.

While soldering, I had to take into account that I would have 3 power supplies available: one from each BEC of each ESC, and an extra separate receiver battery with a 10A sBEC.

As I was going to use an RB20 from Frsky, it supports dual power supply, I usually use one power supply input for the receiver battery/BEC, and one for the ESC BEC.

As I have 2 ESCs, I combine their 5V output through a dual Schottky diode:

This has proven to be a very reliable solution, for a relatively low cost and a high peace of mind.

I then tested each power supply separately, to make sure that I do have the redundancy that I think I have.

When assembling the model again for an all-up test, I got a nasty surprise:

Clearly, something was wrong.  Either it was a warped fuselage, or a somehow bent wing tube.

The wing tube was bent allright, but luckily I could find an easy replacement, even with a larger wall thickness from the local hardware store.
When put next to each other, the bend angle of the original is clearly visible:

But oddly enough, that didn't solve the misalignment of wings and horizontal stabilizer.

In the end, I solved this by shimming the latter at one side by 1 mm, and that literally set things straight.

 

[Chris Walby]

On the point of the wing tube and more importantly I was going to chip in about he retracts and its only my opinion from experience.

 

Clearly the UC needs to be strong enough for normal landings, but I would not beef it up anymore than that on most models and especially the BH mossie as its such a light construction.

 

if you get the landing wrong you will bend a pin, tough but if you have a spare its NP. If you beef the UC up and lump it in it will rip the servo mounting plate out of the nacelle or rip the nacelle out of the wing. The latter will be a lot of work to put right (I wonder how I know).

 

A bit like the wing tubes, good enough for normal use, bend and save additional damage to the wings/fuselage. You could put a carbon tube but in the event of a crash it will rip its way through the wings.

 

 

Out of interest where did the play come from regarding your flap mod? Linkage or flex ? and were the rod tangs glued into the flaps or just slotted?

Edited April 22, 2022 by Chris Walby

[Hangarqueen]

Thanks Chris for your input and views on this.

I totally agree on your viewpoint on this.  We actually have to choose the weak point in the construction, as "something's gotta give" ?

 

Our flying field holds a couple of challenges, due to serious airspace limitations on one side of the runway, making nice, long stable approaches almost impossible at times.

I'm hoping that this last modification will just prevent the pin from bending or coming undone from the retract.  My guess is that if I were to have a really heavy landing, that the retract would be torn out of the nacelle, or the struts bent or something of the sort.

As for the play on the flaps, most of it comes from the fact that the connecting wooden dowel doesn't fit snugly into the openings of the nacelle where it goes through.  I misjudged this when I glued everything together; I should have secured this in a better way.

I don't know what you mean by "rod tangs"?

 

 

[Hangarqueen]

Motors and spinner were a different story.  As we can only fly electric on our field, the choice is simple enough.

I'm a fan of the eCalc application, with which you can find a good estimation of the performance of a given motor and prop combination.  As it is a Mosquito, I really wanted a 3-blade propeller.

I ended up with an NTM 3548 900 kV motor and a Master Airscrew 11x7 "-bladed prop.

According to eCalc, this should be some sort of overkill for this model

In reality, it was a lot less.  Telemetry from the second flight showed a total power of 1200W, instead of the calculated 1600.  Airspeed seemed to correspond closer.

 

But first the installation.

The original firewall is designed such that it can easily be moved forward or aft, depending on which motor one is using.  When I first trial fitted my combo, it was clear that the whole assembly had to be moved as much forward as possible for the spinner back plate to end up in front of the cowl.

I did have to glue in some reinforcement then, to allow for the pull of the motor on the engine mount and support.

I also ordered a set of spinners from Sarik in the UK, which were a perfect fit and very scale shape, but I couldn't center them properly.  That was due to my lack of skills, not to the product.

I decided to give some spare spinners from my foamie Freewing Mosquito a try, and to my joy I found that they were a perfect match in size.  I only had to "dremel away" some material at the back of the back plate to get the prop adapter to fit.  That was within my skills limitations ?

They look fabulous!

Again, I couldn't resist having a look at the assembled model, and I was very pleased with the looks

Then came the time to prepare it for a maiden flight

I chose to insert a soft balsa support at the bottom of the nacelles, to protect them from breaking in case of a belly landing.  Also fitted mounts to connect the back of the nacelles to the front part

The flight battery is inserted from the front, I added a vlecro strip to keep it securely in place

The canopy was originally intended to be kept in place by a couple of plastic bolts at the back.  That appeared to be extremely fiddly, so I replaced those with some strong magnets.

They are so strong that I had to add a small handle on top of the canopy, to pull it loose from the fuselage.  But it works really well.

I then started assembling everything again, when disaster struck.  While softly (I have the physical strength of a chicken...) tightening the propeller nut, the threaded shaft just broke in 2 pieces

I opened an RMA with HK, and to my surprise they accepted this and sent me, after a very long delay due to the Chinese New Year, a replacement prop adapter

These adapters seem to be made of a very soft Aluminum, hollowed out to accept a bolt to hold a spinner.  As my spinner is attached differently, I decided to insert an M3 bolt for reinforcement of the prop shaft

I had to grind off the contours of the bolt head, to allow the prop nut to pass

And now she was really ready for a maiden flight

[Hangarqueen]

And then the day of the maiden came.

I had been waiting for weeks in a row for some good weather during my free time.  Last week there was this one day when the wind was very calm, but they forecasted rain.

While I checked the forecast, I saw that I had a window of about one hour left before the rain started, so I quickly loaded the Mossie in the car and drove off.

Assembly goes really quick, last preflight checks, hat camera on, and ready for departure

I have video of the first two flights, but I seem to hold my head up too high for a good framing.  So I took a couple of still images from the video material and cropped the "good parts".
As already mentioned, it tracked heavily to the right, which surprised me a bit.  The climb was more than powerful enough to look non-scale

I only did some turns around the field, just to get it trimmed out correctly.  I left the gear down because I didn't trust it yet.

It took a couple of attempts before my approach was right.  I tried out "half flaps" at altitude, and noticed no real ballooning, so I used this setting for the first landings.  As this flaps setting didn't cause much drag, the approach had to be long and shallow, which isn't easy with a camouflage model on a green backdrop.  I will add landing lights to facilitate this.

In short final, as I eased the controls for the landing, the model veered to the right again, causing the right wing to drop a little.  I let this surprise me, and the Mossie landed on the right wheel first, causing the gear pin to bend, as mentioned above.

I made the reinforcements and had a second flight.  As you can see in the picture, I landed again at the right side of the runway.  But the landing was much better, with a little bounce. 

It is visible in the picture that the landing gear isn't in its normal position anymore, as it came loose.  But I felt happy with these flights.

It flies really stable, solid, powerful climb, scale speed in the air.

But I noticed that I couldn't really fly hands-off for long, and the tracking to the right bothered me.

Post-flight, I had a look at the telemetry log, and noticed a constant offset in the rudder channel.  I then remembered that I programmed a sub-trim (which I normally don't use, I prefer to center flight control surfaces in a mechanical way), because it was impossible to center it mechanically (due to my integrated rudder servo and custom control).  I then looked at the rudder again, and notice that even though the top of the rudder aligned with the vertical stab, the bottom of the rudder was clearly off-center.  Even better (?), it was deflected to the right (!).  That explains a lot of the difficulty that I experienced with the tracking, and even the deviation in short final (also to the right).

While looking at the rudder, I noticed another problem: the tail wheel hinge had broken off:

This mean disassembly of the whole tail cone assembly, and installing a solid metal hinge that I found in the local hardware store

This will hold a lot better.  I took advantage of rearranging the tail wheel position while extended, because it sagged a bit too much when the weight was on it.

Both positions are now closer to scale too:

I had to correct for a warped right aileron too, which was pointing up at the outboard side (which would also contribute to a pull to the right).

And before the second flight, I made another improvement in cable routing.  I found the motor wires uncomfortably close to the elevator servo, so I installed some hooks to keep them away from the servo

Disregard the large XT90 connector near the servo, that is from the disconnected flight battery.

All in all, I'm happy with where this model is now, and can't wait for another good flying day.  Way too much wind this weekend, so the wait is on again.

Meanwhile, I can prepare this other beauty for the next season