Sun n Fun Preview

As my 13 follows know, I have been in the Czech Republic for 3-1/2 months in what started as a 2-week trip last November. Finally, I am back in the New World. But just prior to leaving Prague my wife and daughter showed up. My son is already living in in Prague attending one of Europe’s best technical universities. So, for the first time in 10+ years, our family is together in a mini reunion (1 day before I flew out to UK) in the city the kids were born in.

But I had to fly to UK to deliver a Merlin the next day. Then I rushed to Florida to meet and unload the container I had helped pack a month earlier.

A big THANKS to Merlin Lite customer Art. We both totally exhausted ourselves unloading 3 finished aircraft in 5 hours. Now the work is focused on getting these aircraft assembled and flown for the upcoming SNF show.

More aircraft than I can fit!

First look at the Merlin Lite 100% finished including the new spinner!

And the Merlin Lite panel. Remote choke is bottom left. Then 12v USB power supply. Above left is trim and avionics master then EFIS. Then an iPad on Velcro. Bottom center are fuel valves. Right side is engine EMS and engine control. Not in the photo is the throttle and brake on bottom left and flaps upper left. Not your 80’s ultralight!

Next work is flying the green/cream Merlin with the HKS. Then preparing the Merlin Lite on floats for the show. But I could not wait, I had to take a quick hop in the Merlin Lite:

Hope to see all my friends at SNF next week! And of course I did NOT smuggle any Czech beer in the container. At least I was not there, I didn’t do it, and nobody saw me…..

The Float Blog

Yes, I am still in the Czech Republic. Aeromarine has some very important work to do here that we can’t talk about. But there is a lot of other work we are doing that we can and will talk about so let’s get on with it.

Yesterday we packed and shipped 3 aircraft into a 40-foot container going to Lakeland, FL. This container will arrive about 2 weeks before the Sun N Fun show starts. That is unusual. Usually, the paint is drying on my flights to Oshkosh or SNF. But of course, I have to return to Florida before then and that will happen after my 2-week trip turned to 3-1/2 months.

I will need the two weeks for test flights and to prepare our booth and the aircraft for the show. I have a long list of work to do. Seems like I say that often.

So, what’s in the box?

Even the container packing is CAD-designed. Then a lot of custom mounting fixtures for floats, wings, and wheels are welded and bended up. Closed cell, high density foam is cut on a very large router and matches the wing profiles exactly. I guess we could call this matched airfoil packing.


We packed show supplies too. Doubles to weigh down the aircraft for shipping. Of course, customs has all the details.

We have a really nice Merlin with an HKS we shipped for show display. I will assemble and fly this Merlin to the show.

We have finally the first production model of the Merlin Lite which I will also fly at the show. I plan to fly this Merlin Lite in the factory demo slots at Paradise City should anyone want to see it in action.

And for me, this is the showstopper: The new Merlin Lite on our new Aeromarine 750 floats!!!! I just don’t think there is anything like it in the ultralight market. Correct me if I am wrong but only after you see this aircraft in person.

Firstly, it’s a Merlin Lite. That aircraft by itself raises the ultralight bar a mile or two. Then it’s our well-proven floats that are now made with precision matched-hole technology to make them the most perfect shape ever. Then there is the installation which I have never seen in a float costing less than $50k. The photos will speak for themselves. Come to the SNF show just to see this aircraft.

After the show, I plan to make the first test flight of Merlin Lite #2 and it will be from the pond! And here is the pond in my back yard:

My private seaplane base application is in the final review with the FAA.

But I diverse. Getting back to the Merlin on floats. Here is the installation:

Simple. Just hoist up the aircraft, remove the main gear, bolt on the floats. It is simple, if you have the mounting system designed on CAD and built perfectly. Then everything fits and, in a few hours, you are done.  But only if you have the perfect installation parts. Have a look at these details:

Perfect geometry on the fittings. Bolts line up, struts line up. Spreader bars bolt right on. And, of course, the struts and spreader bars are all a custom aluminum airfoil extrusion.

Every Merlin Lite has float strut pick-ups welded on the engine mount. When the main gear leg is removed a custom fitting bolt in to pick up the rear struts. So, changing back to wheels or skis when the pond freezes over is quick and easy. And yes, for those who noticed, the nosewheel will be removed. Just left on for shipping.


One water rudder is enough for an ultralight so why pay extra? But if you will only have one it should be this one. In the cockpit you can see a push rod connecting to the rudder pedals. If you follow this back it goes to a bellcrank which actuates a teleflex cable which moves the water rudder hopefully the same direction as the main rudder (it does of course).

It gets even better. Note the round object in front of the throttle quadrant. It has a handle and a friction lock, when you rotate this forward it pulls the water rudder up. Proper seaplane pilots always retract their water rudder before take-off.

Even the fairings are impressive! 2-part 3-D composite fairings nicely finish off this quality installation.

Coming soon to a blog near you: More Merlin Vtwin videos. And a video of our Czech facility. Watch this space. And see you at the show?



News from the Czech Republic

I took a two-week trip from 25 November and it is now going on 3 months and will be well into February before I finish here. Czech version of Gilligan’s Island except it’s freezing cold with snow and rain here. I know I will be back to the New World soon. Sun-n-Fun is the end of March, and I must be there showing the new Merlin Lites and 750 floats. But first I need to get those show aircraft finished and shipped.

The work I am doing here is very important. And not just for all my Vtwin Merlin and Merlin Lite customers but there is some conflict nearby you may have heard about. And my readers may have noted that I do work in that area on occasion. Connect the dots. That is all I am going to, or allowed to say.

But being here so long has some real results that my customers will benefit from soon. We have had time to refine the Vtwin installation in many ways:

  • The engine installation is improved.
  • The engine installation manual can now be written (which I will do) along with drawings and a verified parts list. Then I can build stock in Alabama and complete orders properly.
  • The engine wiring harness is done and out for fabrication.
  • The new avionics wiring harness is done and in fabrication.
  • The EFIS is mostly programmed. MGL is making some custom modifications for the Vtwin. We will be able to upgrade each panel with a micro-sim card to have the Vtwin and Merlin parameters instantly and perfectly.
  • The Merlin Lite program is nearly finished. We have a flight test program to warp up then send the 2 Merlin Lites here direct to Florida to hopefully arrive before the show starts. One of the Merlin Lites will be mounted on our new 750 floats. That will be very impressive.
  • The new Merlin Lite panel is finished.
  • A new video will be posted soon. My son attends the Prague technical university and has some time off between semesters. BTW, he passed all his first semester exams, and this university has a 50% failure rate. It is the leading A.I. university in Europe and his studies are in that field along with electrical and computer engineering. Not easy subjects. His job next week will be to get some air-to-air video of the Merlin. Plus, to edit the 3 hours of flying I recently did, mostly with my hands in my pockets flying circles.

If we can get the ship booking, we will be able to load 2 Merlin Lites and a Merlin and ship direct to Lakeland just in time for the show. Finally, we will begin making Merlin Lite deliveries.

We use CAD for everything here. Even for container loading.

Here I am making the new Merlin Lite panel. First step was the CAD layout. After a few revisions the file goes to the laser cutting machine in the basement. Then I get to debur it and trial-fit the electrical components.

After fitting, the instruments pop out and the panel spends a day in the paint shop.

Then I get to install the components. And I also cut a scale iPad Mini 6 to confirm the common iPad fits. But personally, I just stick a magnet phone mount holder on the panel and use my Android with the Garmin Pilot app.

Now I have wired up the panel into the Merlin going on floats. BTW, right after SNF show I plan to get plenty of video of the first Merlin Lite flying on floats.

Panel notes:

  • Keep it simple. Even at that it has 1000 times more sophistication than your typical ultralight.
  • Upper left is the electric pitch trim.
  • Below is the master avionics switch and there is a pilot hole next to it for another switch such as strobes.
  • Then the EFIS. You can look up the specs. It is a feature-packed unit with everything you would expect in an EFIS plus GPS for ground speed.
  • Below that are the 2 fuel gauges. I have wired up a low fuel warning light built into the gauge. You can see it if you look carefully on the right gauge.
  • The sub panel has 2 12v USD power supplies to keep your phone and tablet charged and coffee warm.
  • Then you have two simple fuel valves. Choose left, right, or both tanks.
  • Then all that real estate for your pilot-installed options. Generally, some GPS moving map.
  • Upper right is the Polini-programmed EMS for monitoring your engine tach, temp, and hours. There are a few other features, but I just install what is necessary.
  • And below that is the Polini engine control that has on-off switch, starter, and two buttons for mag tests. The Polini has one electronic ignition and one mag ignition.

But my main work here is on the Merlin. We have made a lot of modifications and will be back flying later this week. I will show you what I can.

Meanwhile, a lot of Merlin parts are being made. We have stacks of spars and ribs and other parts building up. I think we are all looking forward to a nice flow of Vtwin installation parts and new Merlins.




New Merlin Lite Flys!

Another ’bout time comment coming. I have been in the Czech Republic over a month now getting important stuff done. First priority was flying the Vtwin-power Merlin which was a big success. I have 3 hours of video to edit for an upcoming YouTube on that effort. Next was to finish and fly the Merlin Lite. I had the engine and panel wired in under 1/2 a day.

It is such a simple yet complex panel. This ultralight has a GPS-equipped EFIS with a dozen parameters, fuel gauges, electric trim, engine monitor, and Polini engine control box all nicely mounted in-dash for a clean look and a huge space for your iPad or moving map or phone and nav software of your choice. Under the panel is a 12v USB phone charge plug and the two fuel tank valves. The panel hinges on the bottom for full and simple access.

That large NACA vent is the cooling air inlet. We have plenty of room behind the small Polini 303DS engine, so the radiator found a home there and it is quite effective. Temperatures were at the bottom end of the specs so I will install a thermostat to raise them up a bit. I am confident that there will be more than adequate cooling in Florida summers, even on floats.

One more detail photo. How many ultralights have this kind of cargo space and the ability to carry a load?

Here you can see the ground-adjustable carbon prop. We will add a spinner. Note that the Polini has a clutch which makes starting and idling really nice. Prop just barely spins, if at all, at idle.

Now that’s some wingspan! This aircraft will be excellent with electric power, and we have already begun the design. For your viewing pleasure:

And here is a short video from my phone.


I didn’t realize that it was so quiet that I could record my voice or maybe I would have kept up more narrative.

Here is one beautiful wing!

And some artwork from the Hangar Bar in Prague. Kinda seemed like the right place to be after a good day of flying!

Now both aircraft are back in the shop getting finished and fine-tuned. I will remain in Prague for a while longer to wrap up this work and finish the documentation and parts needed for our build programs. Meanwhile, another container of Merlins arrives to M-Squared this week and we need to be ready to get builds done!


Merlin with Vtwin Flys!

How to choose a title for this blog:

  • Big news from Czech!
  • ’bout fkng time!
  • Great success after 2 years of work!
  • Even better than expected!
  • Never a doubt!
  • What took so long?

Pick one.  Anyone. They all work. And I know, it has been a while since the last post but I (we) are tired of hearing how close we were. Today we flew for 18 minutes. Short flight because EMS is not yet programmed for the Vtwin. I expect to get most of the programming done tomorrow then we can fly a lot more. And get some decent video. I will try to get some video posted ASAP.

First impressions:

  • The engine starts instantly. Just like you would expect from a modern, fuel-injected, computer-controlled, electronic ignition engine.
  • The sound is perfect. And very quiet. No more 2-stroke whine. Sounds like an aircraft should.
  • The power is impressive. I will quantify it in due course with take-off, climb and cruise data. But it feels great! With full brakes on and wheels locked the Vtwin drags the Merlin across the grass. That’s impressive. Not even with full power.
  • The MGL panel looks and works fine. Once programmed I will copy all parameters to the micro-SD card then post for everyone to download for their MGL EFIS/EMS.

So why did it take so long? Short version answer:

  • It has to be done right. Our engineers have done a fantastic job.
  • The engine needed customization:
    • Engine mount
    • Cowl
    • Custom wiring harness
    • Custom cooling system
    • Custom oil filler
    • Custom reduction drive
    • Custom-made cooling system
    • Matched propeller
    • Custom dual-pump fuel system with electronic switch and fuel return lines
  • The avionics are complex:
    • Mounting tray for all the remote components
    • Panel laser cut, anodized, then laser-engraved
    • Custom fuel management circuit board
    • Special switch & breaker circuit board
    • Perfectly-matched custom made wiring harness

There is a lot of detail I will get into later on our technology. Maybe a special page on our web site. But I think what we are doing is exceptional in the kit aircraft industry. I do not see such technology from most of the other kit suppliers and no one at our price point. See the latest article in Kitplanes magazine about engines and engine package pricing costing upwards of $60k!

So back to the flight. The engine runs flawless. No issues whatsover. But I did forget to mention to the Czech test pilot that the EFIS was programmed in MPH not KPH so his landing was a bit fast… oops.

For your viewing pleasure:

Other business in summary:

  • I have been in Czech a month and will stay longer to get more hours on the Merlin/Vtwin.
  • Merlin Lite is at another airport getting ready for flight test program. I will finally have time to work on it also.
  • New TrueLite ultralight is in design evaluation.
  • A Merlin builder in California reports first flights with HKS power.
  • Another HKS-powered Merlin is now flying in Ohio.



Big Blog From Prague

OK, a lot to report so I will get right on it and save the dribble for last for those still reading…..

This trip to Tech Pro Aviation in Olomouc, Czech Republic, was maybe trip 4 in the last 1-1/2 years or so. I should not have to go over there so often but if you want things to get done….  But to be fair, the Czechs get a lot done if they know what to do. And the Vtwin project was a moving target with all the R&D we needed to finish. And to be clear: I might have underestimated the amount of engineering required to make the Vtwin happen.

I have been told numerous times at airshows “What a great idea! Why hasn’t anyone done this before?” I know why. Its snot easy. It is basically impossible to buy Vtwins factory-direct and built to your specs from a company making thousands of engines each month. Our Chinese connects made that happen. And that was just the start. We needed custom reduction drives designed and manufactured. Then we designed the cooling system and had that custom fabricated. Then the fuel system which went through a dozen revision. Plus, we have the custom wiring harness designed and will be wired up to our specs with all perfect lengths and connectors. Wiring the engine can be done now in minutes. And then there is the Deluxe panel. We are now designing an avionics tray to mount all the remote components behind the hinged panel. And another custom wiring harness needs fabrication. Plus we designed two custom circuit boars to control the entire avionics and greatly simply the wiring. Even I can wire up an aircraft now. Kind of. And, of course, the panel itself which is now done and getting laser cut, electroplated, then laser-labeled. Send me your N numbers!

And the cowl, radiator, exhaust, and engine mount all have to fit perfectly. We found a frustrating 5cm difference in the engine mount position from one CAD system to another which had to be sorted. It seems like endless work. And for those waiting so long for these components a frustrating wait to have a finished airframe with nothing to install.

I plan to deliver as many of these component in person to those I can drive to. And take some time with each builder to get them sorted and jump-start their building.

I keep saying it will be worth the wait and I know it to be true. The Merlin Vtwin will set a new standard for sophistication and modern engineering in a LSA-class aircraft.

Here are some finished Vtwin cowls shipping soon already painting to match customer Merlins!

Here is proof that Martin and I actually do some work! And a photo of the latest BRS installation with new shroud covers.

3 Merlins are ready to ship. We have had some cancellations so orders were shuffled. Merlin #4 is in the paint shop now. When done we can ship. ETA to Alabama is October sometime. Side note: It is sad for me to have a customer cancel due to health reasons. If only I could have delivered sooner they would have realized their dream. And it was good not to take huge deposits so I can manage the refund.

Some Merlin discussion points:

  • Inflation is too often simply an excuse to raise prices, I am not on that wagon. How much more should we charge if the price of aluminum doubles? Say it jumps from $5/lb. to $10/lb. Sounds like a lot huh? There is only about 200 lbs. of aluminum in a Merlin so that would add $1k to the cost. Aluminum is now costing more because it is directly related to the cost of electricity which has really gone up. But it won’t double the cost of the aircraft. We will raise some prices but that is mostly due to added value like on the panel electronic and wiring.
  • We will move Merlin assembly to the USA and will have higher labor costs. But we think that cost will be offset by lower freight costs.
  • Electronic components are a real issue. We have to design our circuit boards around available components. MGL has to do the same. There are incredibly long lead times for electric chit. We do order the panel components as soon as an order arrives so this lead time is minimized somewhat. See? It is not just us late.
  • We have plenty of engines and reductions drives. I will feel like Santa finally delivering these presents. Hope my sleigh is big enough! I didn’t think about that until now.

The Merlin Lite is really looking good! New cowl is finished. Floats are finished. Next week Merlin Lite #1 goes to the airport for final assembly and test flights. I am not going to make any more excuses. It has taken about triple the time I expected. It is what it is. Who wants me to take short cuts? Here are your Merlin Lite bullets:

  • The panel is great. EFIS, Trim control and indicator. Two fuel tanks (only one is allowed for Part 103 to stay under the 5 gallon limit), EMS for the engine monitoring, and the Polini dual ignition engine control. Huge space for your phone or iPad for navigating those long cross county flights.
  • We will soon conduct a fully-compliant to the Czech/German UL-2 standard flight tests. And we will physically test the key components such as the wing. So we won’t be shipping these Merlins to USA just yet. Let’s get it done right.
  • We will build and bench-test a couple of electric power designs we have been working on. We can easily retrofit the electric power on to a Polini-powered Merlin Lite. I am really looking forward to flying the first viable electric-powered ultralight floatplane that doubles as a self-launching glider.
  • Speaking of floats, they are looking great! They might even be big enough for the Merlin. But really, the Merlin Lite is ideal for floats with the slower speed, bigger wing, and huge flaps. The installation with streamlined tubes is done. We even have a unique water rudder control using push-pull Teleflex cable and a way-to-sophisticated water rudder retract lever.
  • These 750 floats are suitable for a lot of ultralights. We will start building them in USA later this year.

And here is my back yard airport. If you look closely (And not at my wife and daughter), you can see the waterski course which doubles as our seaplane runway. And the windsock is already in position and operating.

Still reading? The dribble starts now. Today my son flys to Prague and will attend the Czech Technical University CVUT to study electrical/computer engineering. This university is one of the best in Europe. I suppose they accepted him for their hockey team and not his stellar grades. But he is smarter than the average bear so should do OK.

My wife will fly here also to help get him sorted into the dorm and Czech life. Should not be too hard as he was born in Prague and Czech was his native language half his life. I would like to stay too but have to fly back to USA for the Midwest Expo starting next Thursday. I will miss his hockey try-out. Sigh. But also really need to get back to work in Dayton too.

Finally I have  a day off and can spend it writing a blog. Or moving on to Plan B!


Updates before OSHKOSH

In no particular order:

This is how the fuel and cooling plumbing will look. Blue is cooling. Green is high pressure fuel. Red is low pressure fuel return line. All these hoses are custom molded to our 3D shapes and dimensions. Super easy to install. No other fittings besides a handful of clamps. This makes for a clean, effective, light, and simple fuel/cooling system. Not to mention it looks great!

Here are some photos of how these silicone hoses are made. The tape is actually shrink wrap. A steel mandrel of our CAD-generated shape was fabricated then inserted into the silicone then wrapped in the heat shrink and baked. After the baking process the heat shrink and mandrel are removed and we have perfect fitting hoses.

Here is a video just posted by our friend Brain from Columbus. He is waiting on his Merlin kit and close enough to come visit us on occasion in Dayton. And pretty good at making videos. Maybe I can bribe him into making one from Oshkosh.

Speaking of Oshkosh, we will be in our usual space just north of Building C in the main display area. We have only one Merlin and don’t have any Merlin Lites to show but we will have plenty of updates on the finished Merlin Lites that didn’t arrive on time. And we will show 3 tents full of our innovations and technology. DEPOD, RAES, HYBRID, Hyper-STOL, Amphibs, to name a few. Plus, the Vtwin with all this nice plumbing should make the stand.

For those future Merlin owners, we will likely have a small price increase AFTER Oshkosh. This has little to do with inflation but a lot to do with all the technology we keep adding to this build. For those builders waiting so long to get the parts they need to finish their Merlin’s it won’t be much longer as plenty of parts are coming in soon. Thanks for your patience and I trust it will be worth your wait.

Builder Don has finished the right-side circuit board. Panel status:

  • Left-side circuit board Revision 1 has been ordered and should arrive in time to show at Oshkosh. This is the production version so plenty of boards are ordered.
  • Right-side boards are recently ordered and will likely arrive shortly after the show.
  • The final dimensions are now known so we can have panels laser-cut. We will bring the first panels and bring them to the show also. One will be anodized and laser-engraved and have the EFIS and maybe the left-side panel installed.

Here is Don’s description of the new ‘fuel-control’ right-side panel:

The holes for the switches and LEDs are on mechanical layer 2. There are five mounting holes but those are not part of mechanical layer 2. The tank-select switch is three-position: Left, Auto, Right.

The AUTO MODE SELECT switch to the right of the tank-select switch allows for automatic tank selection based on “TIME” or “BALANCE”.  With the Tank-Select switch set to “AUTO” and with the mode select set to “TIME”, the tanks will switch automatically every 10 minutes (or whatever interval we decide to program into the microprocessor).  When “BALANCE” is selected, then an (as yet to be determined) balance will be maintained automatically between the tanks.

Setting the tank-select switch to either “LEFT” or “RIGHT” will always disable automatic tank selection.

The four green LEDs are (from left-to-right), Pump 1 ON, Pump 2 ON, LEFT TANK, RIGHT TANK

The two red LEDs illuminate whenever either pump is turned on and the respective fuse has failed.

Alright so what does this mean?

  1. With a fuel-injected engine one pump must always be on. We install 2 pumps for redundancy. The pilot can choose to run either pump. Or both for take-off and landing if desired. Just make sure one green LED is lighted.
  2. The electronic fuel selector has a horizontally mounted switch. Simply choose left tank or right tank. Switch tanks whenever you like. When flying cross country, I usually will fly 1-1/2 hours on one tank then finish the flight on the other tank. Then I know how much fuel I burned and how much remains. Good to know if you don’t trust your fuel gauges.
  3. But wait, there is a middle position? Yes. This you might find in your friends’ Gulfstream. If you choose the middle position, then the fuel tank selector will automatically change from left tank to right tank based on a time interval or a fuel level interval.
  4. The toggle on the right side gives you the choice to have the tanks balanced automatically by time or by fuel level. You choose. We will have to decide what those intervals are and will program the microprocessor to follow those intervals.

Note: The Merlin is not out of balance with one fuel and one empty tank. The tanks are close enough to the center not to make much difference. Having this automatic fuel balancing option is a convenience and also a safety feature. Not everyone remembers to switch tanks on time.

See you at the show!


Alabama Build Center on-Line!

Ok so which is hotter? Ohio, Florida or Alabama? 3 pizza ovens come to mind. 10-hour workdays in this heat are truly exhausting. But the builds must go on. Here are your news flashes:

Work continues in Ohio on the Vtwin installation. Now the fuel system us getting fine-tuned. Green hoses are high-pressure and red hoses are the return lines. We are just getting the proper pressure regulator sorted. We will display this installation you see above at Oshkosh. I think it is exceptional and worth a look.  So much of aviation is still stuck in the past.

I have two main objectives for this first work trip to M2. Wait, we need a name for this new build center. I am open for suggestions. Pizza oven is already taken.

  1. Build a proper Vtwin FF pkg inventory. This was accomplished. Now we have a section for the redrive BOM, and the entire FF PKG BOM sorted by sections.

2 shelves cover the FF PKG BOM. One shelf is for extra hardware and supplies. 4th shelf is for queuing up components for the customer builds. Each build gets a dedicated shelf. And we have a lot of inventory. Overflowing with reduction drives and radiator kits. Plus 3 builds have all the avionics stacked up. Plenty of strobes too. We are mitigating the supply chain shortage by ordering everything as soon as an order is confirmed so we are good with most everything. Except we could use a lot more airframes……

2. We do have a build in progress. And it is going very well. As we complete all our technology and protocols, we expect these builds to go very quickly, and it is showing already. In only 2 days we:

  • Installed the engine and mounted the reduction drive and some accessories.
  • Installed the wings and tail.
  • Got a good start on the BRS installation and loaded the rocket fuel.

Yes, there remains a long list of work to do but it is not complicated, and we will get er done. But tomorrow I need to return to Florida to get out of the heat. I will leave many tasks in Paul’s capable hands while I go prepare for Oshkosh.




News from around the World

Last week the Merlin Vtwin in our Dayton workshop was nearly finished. The top cowl needed a bigger bubble and will be out of the composites and paint shop by the end of next week. So, I flew back to Florida to take an entire day off (yeah right, means I am answering e-mails, packing the trailer for Oshkosh, and writing blogs). I hope to play some ice hockey, then water ski, then BBQ tomorrow. Monday, I drive 8 hours to spend the week with Paul at our new build center near Mobile, AL. We have a couple of Vtwin Merlin builds to get going on.

So here is what I have to show for our hard work last week:

You have to look closely. These are not last week’s photos. Cooling system is 100% done and filled. Oil is filled. Fuel system is also done. Panel is operating. Wing tip navs and strobes are working. This Merlin is basically finished. Next trip we plan to have the FAA visit for the airworthiness inspection and certificate issue. Still need to program the EFIS and do the final cowl fit and set the prop pitch. Not so much work left!

We have mapped the fuel and new coolant hoses on CAD for our supplier. We will have new custom fitted and even colored hoses in stock by Oshkosh! Our FF PKG keeps getting better and better!

BREAKING NEWS: The Vtwin Merlin weighs about the same as a Rotax 582 Merlin!!!!


This is big news. This means the Vtwin can replace any 582 installations without a major weight issue!

We projected the weight to be a bit more than the 582 and less than the HKS. We are a lot closer, if even lighter, than the 582 installations. Note that this Merlin has the deluxe panel with big EFIS, transceiver, transponder, 4 antennas, and nav/strobes. But the cowl was not installed at the time of the weighing so add 4-5 lbs. We are pretty close on the balance as well. Looks like we will have to move the battery to the rear shelf and the numbers will fall into place nicely.

Builder Don has made some fine-tuning on the left side circuit board and sent the drawing off to the circuit board printer with an order for 50 copies. We should have those boards back by Oshkosh too.

BREAKING NEWS #2: Another Aeromarine Vtwin is flying!

Replica P-40 by builder Gord has now flown 1-1/2 hours with our Vtwin!!!! He only needed to upgrade the isolation rubbers to a firmer size to handle all the torque better. Nice.

I know, everyone wants to know 1) If they will get the upgraded parts and technology, and 2) When!?

The photo on the left has one Vtwin and one Merlin Lite cowl. Note the NACA inlet for the radiator on the Merlin Lite cowl. And several Merlin cowls finished and in the paint shop. Plenty of engine mounts and exhausts shipping soon with some cowls. Plenty of Vtwins and reduction drives in stock. Working on getting more props and spinners. And, of course, everyone gets the latest versions. Finally, some action.

Today I began the Oshkosh prep. I sourced a used trailer that has a tilt option. We will build some wheel channels and wing holders so one person can wheel up a Merlin or Merlin Lite onto this trailer. But for now, I just bolted on some wood support to transport the DEPOD wings to Oshkosh for display. BTW, the 2nd patent on DEPOD was allowed. I know, I told you already. But it is a big deal. To me at least.

The 2 Merlin Lites are getting closer to flying in the Czech Republic. I did say world news after all.

The Merlin Lite on floats was supposed to be at Oshkosh but the container would not arrive on time. And air freight quotes ranges from $17 to $60k! You will have to settle for photos and maybe some video at Oshkosh.




Tonight, I fly to Dayton to finish the Vtwin Merlin. My honeydo list is under control so I actually have time to type some random dribble.

  1. DEPOD: Our Continuation in Part (CIP) for the DEPOD patent was allowed. This is essentially a second patent which expands on the first patent making it considerably stronger. We have added features such as DEPOD motors and props in the horizontal and vertical stabilizers which will of course enhance the STOL performance but also can eliminate the classic base-to-final stall/spins which is usually a fatal error. DEPOD automatically keeps the ball centered preventing spins and can also keep the aircraft inside its’ flight envelope preventing stalls. Kind of like lane assist on many new cars. It can also eliminate the engine failure on take-off issue. The pilot no longer has to choose to land straight ahead or try to make the often-impossible turn to land on the runway. DEPOD has plenty of power to continue the take-off and climb and continue around the pattern for a normal landing.


I removed the DEPOD wing from the Merlin Lite to take to our display at Oshkosh. The Merlin Lite has the short wings re-installed now. As we now have the first finished production Merlin Lites and floats to go with them, we do not have to show this beat up protype any longer. But we will have to air freight a Merlin Lite direct to Oshkosh as the freight companies cannot deliver an ocean container in time. Again. Sigh.

2. Cooling System: Our design needed some fine tuning as the radiator tubes had some engine mount interference.

We solved this by reversing the radiator spigots. Now we can position the radiator in the exact center of the cowl opening. We also have the pressure tank connection molded directly into the cooling tube. And the overflow tube actually changes ID from 5/15 to 1/2 inch. Having this custom cooling system looks great, has minimum flow resistance, and has eliminated all the fittings and adapters except for the few Oetker clamps. And, of course, makes installation super simple and quick.

3. Fuel System: This system has been finished for some time now just waiting on the cowl and installation of any remaining components to see what space was left and what would work best for the fuel pump and pressure regulator mounting. Now we have a plan to mount the two pumps as pictured below which leaves room for the pressure regulator nearby on the firewall and makes plumbing to the fuel supply and to the engine clean and straight forward.

One pump is plenty. All cars and ATVs have just one pump but this is aviation so we install two independent pumps with check valves so the pilot can choose left, right or both for added security and safety.

4. Instrument Panel Circuit Board: Builder Don has made a few more refinements to the main circuit board which houses all the switches and fuses and simplifies wiring. True plug-and-play. For your viewing pleasure:

Don wrote me recently:

There are essentially no CAN interfaces, nor CAN-Enabled microprocessors available in the near term.  There are MANY (hundreds of thousands) on order by Mouser, Digikey, etc., but with lead times that extend well into 2023.

I have never seen such a shortage of electronic components.  It’s very alarming.

I have in-stock ~200 of the PIC18F2420 and will design around this.  It will eventually require an external CAN interface, but those won’t be available again until mid-late 2023.

Similarly, even simple components such as linear voltage regulators, MOSFETS, etc., are becoming unobtanium.


Don will be able to supply these panel boards, so our builders are covered.

And Florida will have a Chip shortage this week as I will be in Dayton……