TrueLite Guest Blog – Francesco Di Martino – Aviad

By Francesco Di Martino

Newsletter Update: Progress and Next Steps

Dear Customers,

We want to share some updates. We are working hard on this first production batch, which includes important changes such as the integration of flaps and a longer wing, and longer fuselage, causing some delays. Nevertheless, there is also good news. The production process is becoming easier to replicate, and our collaborator in the USA is conducting tests with excellent feedback.

We are very pleased with the TrueLite project overall and eager to deliver as soon as possible.

We have encountered some obstacles recently, but we are moving forward with determination:

Sun and Fun Show: Although we managed to have the plane ready in time for the show, the shipping process took almost 3 weeks. As incredible as it sounds, we didn’t transport the plane ourselves; it was shipped by boat. Delegating the shipping work was not enough. The shipping company did not request the necessary information on time and did not communicate anything essential to make it happen. As a result, I spent day after day managing the shipment to ensure it was loaded successfully and organizing the unloading in the USA on time.

Molding System Development: To improve the production process and achieve optimal stamping results, we developed a method that took us 3 weeks. Working with such thin wing skin and achieving a good result required that the ribs be perfectly at 90 degrees. This now reduces assembly work and avoids manual adjustments.

New CNC Bending Machine: This machinery improves repeatability and speeds up the work, although adjusting it to the existing designs caused some delays in standardizing the process.

re. Edit to add dynamic values like name, email and more.

Version Management Integration: Modifications to the wing and flaps, along with the pressure of the Sun and Fun show, made it necessary to integrate custom software for version management. We dedicated two weeks to this, which now allows us to trace each production batch and its files easily, streamlining our future processes.

General Production: Although we planned to use laser cutting, nearby suppliers encountered problems with the aluminum, so we are cutting everything with CNC. While this offers better control, it entails additional time not considered in our planning.

Next Step

We now face the arduous task of handling accessories, a list that changes constantly with modifications. Therefore, we are considering splitting the shipments to expedite assembly in the USA. Since smaller shipments do not make much difference, we will evaluate the best option with our collaborator. For the kits in Europe, we are still on track and expect to meet the planned timeline, which is very important to us.

Although we cannot yet define an exact delivery date, our initial forecast was for this month in the USA. With the unforeseen issues, we estimate an additional delay of 8-9 weeks. For our customers in the USA, we can split the shipments into separate kits so that work can continue while we address the final adjustments and accessories.

We appreciate your feedback to make informed decisions and your patience and understanding of the work we are doing.

Carretera Orriols-L’Escala, km. 13, 5, 17137 Viladamat, Girona
+34 666385775



TrueLite Update

The dust has settled from the SNF show and now it’s time to get back to the South Lakeland Airport hangar and get busy.

If you recall, the container with the TrueLite arrived from Spain just hours before the SNF show opened. All we could do was unload it and unfold the wings. Now I have upgraded the panel with an EFIS and transceiver, prepared the weight and balance, and, generally, prepared the aircraft for flight.

I came up with the name TrueLite because most ultralights don’t quite meet the low Part 103 weight limits of 254 lbs., or 278 lbs. with a chute. I suppose most ultralight manufacturers did design a compliant ultralight, but most customers pile on options and choose bigger engines resulting in an aircraft over the limit.

I have a few electronic bathroom scales in the hangar and, after confirming a consistent reading of my weight, weighed the TrueLite. It came in at 268 lbs. a full 10 lbs. UNDER the Part 103 limit. If you choose not to have the chute, then expect the aircraft to come in around 5 lbs. under the 254 lb. weight limit. We have a local DAR with certified scales I will hire to document this weight professionally for our FAA records.

The weight margin will allow customers to add a few items although I am not sure what. The aircraft now as it is delivered is pretty complete. Some may choose to install a bigger ‘tundra’ tire. I am not sure it needs it but might look nice. And the speed/drag penalty is minimal as this is an ultralight, and by definition, flys slow.

Here is my panel: EFIS, Transceiver, Flap Control & Indicator, EMS, mag switches, avionics switch, and push-to-start button. GPS antenna is below. 2 expansion holes are there for perhaps transponder or autopilot? I will install covers when they arrive.

Here is the video of a short taxi test made this morning. First flights coming up!


SNF Best Ultralight of the Show!

Airshows back-to-back, travel to Europe and Dayton and more coming. Getting things done makes everything better. So on to the update of what is getting done now.

The new fuel system has been the priority. I thought it was done as the design was settled and all the parts made, including the custom rubber gasket. And a 20-hour test run worked fine. But the internal fuel line wasn’t cooperating with the 180-degree bend. The day after the SNF show I flew to Europe to help sort this last issue. Rubber fuel hose tended to sag and interfere with the fuel sender. Adding support was just more complication we wanted to avoid. We did finally solve it with a corrugated fuel line that took the desired shape in a boiling water bath. Now we have 50 new fuel lines coming in. These fuel upgrade kits will be shipped by air to Alabama build center soon.

Mirrored assemblies.


We also have the first fuel side circuit boards stocked and getting populated. And new wiring harnesses as well. Finally, we can get started on the build programs stacking up in Alabama. Good thing too with another 4 Merlins shipping Monday.

The Sun N Fun show was pretty good this year. A lot less dust and only one bad weather day. Plenty of interest in our line of aircraft.

The first TrueLite arrived just hours before show start. Here we are unloading the container directly to the booth.


2-minute wing fold on display at Sun n Fun.

The Merlin Lite won best Ultralight at SNF show!

And finally, some real progress on our electric system. BTW, we plan to install this system on both the TrueLite and the Merlin Lite. The Electrolite is the electric version of the Merlin Lite. The components are all selected and on order. We are building a couple Merlin Lites in CZ for flight testing.

The first production batch of Merlin Lite parts made. Hard tooling is finished which allows us to build more parts and faster.

And TPA now has a 3-D printer for a variety of small part production.

Sun n Fun and AERO shows are just over, and we already have to plan for Oshkosh.



News From the Czech Republic!

I know it’s been a while, but I don’t write just to hear myself type. It has not been long since my last visit to CZ however, the next batch of Merlins is about ready to ship plus I need to follow up on Merlin Lite production. And I was invited to this symposium in Venice, Italy:

Future Opportunities for Seaplanes & Amphibious Aviation 

You may recall I have a long history with amphibious aircraft and seaplanes.

Here is the link for those interested:

Once in Europe it is cheap and easy to get around, so it made sense to visit Tech Pro Aviation then scoot down to Venice for a day.

My great plan started out terrible. Last week I developed diverticulitis. Of course, I had no idea why I felt so bad, just worked through for 5 days it until just 3 days before my flight. Those 3 days were spent in the hospital getting poked and prodded then with an IV stuck in my arm. They unplugged me in time for my flight which I did not want to miss regardless of the doctor’s advice. I already had two surgeries (hockey-related, I know, shocking), and I know Czech doctors are very good. But maybe I should have stayed home. Probably TMI but again, I toughed it out. And, so far, I obviously have survived the trip. Just took a bit of an effort to write this blog.

So, I will get to it as I finally have somethings to blog about.

The first TrueLite shipped and, if the customs gods are kind, will be on display at the upcoming Sun n Fun show starting 9 April at Lakeland, FL. If we can get some hours on it, then we can fly at the show. Either way, more videos will be produced, including a feature from Dan Johnson if we are lucky.

We will be demonstrating the 2-minute wing fold often. Likely get it down to one-minute.

On to the Merlin. It appears finally we are reaching the end of a very long tunnel, and the light is getting brighter. The improved fuel system is finished and in production. We have a custom cut 3mm rubber gasket coming in a few days then we can bench test. All the other parts prepared and 50 pumps with filters and regulators are in stock.

This new system required a new fuel control circuit board which I have previously discussed. The new boards have arrived. A new panel has been cut and posted to builder Don. He is now fitting all the components to the board to assure the geometry is perfect.

Here you can also see the waterproof quick disconnect for the fuel pump power and fuel level sensor.

We are installing the new fuel system on one of the next Merlins and will be conducting the test flight program for Czech approval of the Vtwin installation. Concurrently, we are updating the build manual and documentation to include every single part and schematic.

We also have plenty of landing light brackets now. Super easy to install to the front gear leg.

And some photos of the new cabin vent NACA.

I plan to bring a fitted instrument panel and a fuel pump assembly to SNF show. TPA will complete the retrofit protocol and video and plenty of fuel assemblies and send by air to our Alabama build center. Then we can finally get on with the builds after the show

And here for your viewing please are the next 4 Merlins nearly ready to pack to the container and ship to USA.

You can also see the new top cowl with improved fairings to provide plenty of clearance for the fuel injectors and cooling hose.

On to the much-awaited Merlin Lite news: Merlin Lite parts are in full production. But we still have a lot of work to do with flight testing, structural testing, and documentation. That will not slow down parts production, just being realistic that this new project needs to be done right and that takes more time than we would like.

The revised plan is that we will finish and fly two Merlin Lites in CZ. One with the Polini, and one with our new electric power system. Then we ship the first two finished Merlin Lites (one being labeled and Electrolite), and 6 parts kit. Paul does not know it yet, but he might have to go to CZ for some assembly training.

I will write more about our electric power system progress later.

Now you can see being silent for a while does not mean we are not getting a LOT done.

See some of you at SNF.


Back to the New World

They let me back into USA. Shocking, I know. Back in Florida now after nearly 2 months in Europe. No idea where my luggage went. Same luggage was lost 5 days on the way to Spain. Now pushing 5 days back in USA and still not delivered. My plan was to go to Alabama right away to ship out parts. But those parts are in my luggage!

I expect the luggage to arrive today, then I will get over to M-Squared and get to work. Some of the work done or in progress:

  • A lot of design details on both the Merlin & Merlin Lite were discussed and sorted so it is now clear exactly what the production aircraft will be.
  • Merlin Lite production is now finally starting. One aircraft will be built to flying for the flight test program in CZ along with documentation and additional structural testing.
  • The next 4 Merlins ship the end of February. Painting has already begun.
  • The balance of the parts needed for the early customers and the build center are under construction.

Here is the mold for the top cowl modification. We needed bigger bubbles to provide fuel injector and cowling hose clearance.

This new brake plumbing simplifies installation. The reservoir is now in the cockpit and the parking brake in line with the brake tubing.

Here are the details of the new fuel panel from builder Don:

Fuel control is now a rotating knob. The CPU retains the auto fuel balance. Select time or fuel level and the CPU will switch tanks based on pre-programmed settings. Here is the description from Dr. Don:

The holes for the LEDs, Fuses, and the Rotary Switch are on mechanical layer #2.  The mounting holes are on the “multi-layer” layer…

There are:

  1. Four mounting holes for #6 screws.
  1. Six holes for the LEDs that are .200″ diameter.
  1. One hole for the rotary switch that is .250″ diameter.
  1. Two rectangular holes for the two fuses (remain unchanged).
  1. No toggle switches — all replaced by the single rotary switch.
  1. One USB connector and related components that are only going to be populated on a couple of these boards for testing and for use later if needed.  I’m assuming a sudo-linear slope from the fuel sending units. The customer units won’t have the USB connection components populated on the PCB unless absolutely necessary.

The adjustment/calibration of the fuel level is like this — It needs to be done in the following order:

  1. Set the “FULL” calibration by completely filling the respective fuel tank then adjusting the corresponding trim pot until the “FULL” LED illuminates.  The “FULL” LED must only illuminate when the tank is “full” or very-nearly “full”.
  1. Set the “EMPTY” calibration by completely draining the respective tank and then momentarily shorting the corresponding “EMPTY SET” pad to ground.  The “EMPTY” LED should then only illuminate when the tank is “empty” or very-nearly “empty”.

I’ve included several fuel sampling “Test Points” on the circuit board to facilitate troubleshooting (if necessary).

The overall board size is smaller than before — now 3.525″ wide by 3.650″ tall.

The rotary switch is 60 degree indexed, and the corresponding functions are shown on the top layer silkscreen.  Here is how it functions:

Whenever the “MASTER” switch is “ON”, the microprocessor is powered and the “POWER” and “HEARTBEAT” LEDs will operate.  The rotary switch operates like this:

“OFF” is precisely that — Both tanks (pumps) are “OFF”

“LEFT” — Left tank (pump) is manually commanded “ON”.  The Left pump is powered and LED (DS2) illuminates, and the “MANUAL” LED (DS6) illuminates.

“BOTH” — Left AND Right manually commended “ON”.  The Left and Right pumps are powered and LEDs DS2, DS4, and “MANUAL LED (DS6) illuminate.

“RIGHT” — RIGHT is manually commanded “ON”.  The Right pump is powered and LED (DS5) illuminates, and the “MANUAL” LED (DS6) illuminates.

“TIMER” — “AUTO” LED (DS5) illuminates and the microprocessor toggles between the Left and Right tanks at whatever interval we want (presently set to 10 minutes).  The corresponding tank’s LED illuminates.

“BALANCE” — “AUTO” LED (DS5) illuminates and the microprocessor toggles between the Left and Right tanks, selecting to feed from the “most full” tank.  The tanks will toggle when the feeding tank is about half gallon below the non-feeding tank.

In either of the “AUTO” modes (“TIMER” or “BALANCE”), if both tanks are below a specific (yet to be determined appropriate) fuel quantity, the microprocessor will feed from “BOTH” tanks, in order to maximize the amount of usable fuel / prevent fuel starvation.

In all instances (except “OFF”), there will be about a 2-Second delay before switching “OFF” either tank (pump).  This should ensure that either pump coming on-line will have developed sufficient fuel pressure before switching off the previously-feeding tank.

When selecting “OFF”, the microprocessor will immediately kill power to the fuel pumps.

When switching from “OFF” to either “LEFT”, “BOTH”, or “RIGHT”, those respective pumps will power “ON” immediately (no 2-Second delay).

The rotary switch has a hard mechanical stop.  “OFF” is always at the Counter-Clockwise limit of rotation.  One can’t rotate the switch Clockwise to go from “BALANCE” to “OFF”, etc.



That is a pretty sophisticated fuel control for anything smaller than a business jet.

There are three more chapters to the fuel story.

The avionics tray is now installed into the Merlin. The avionics components have new positions centered behind the instrument panel. The components are connected to the wiring harness with circuit boards, The components are bolted onto the avionics tray with pre-installed rivenuts. The left-side main circuit board and the EFIS are shifted to the right about 3/4 inch. This provides space for headset jacks on the panel’s left side.

The instrument panel itself is slightly smaller due to its relocation for greater leg room.

Now we have a new fuel circuit board, and that CAD data has been sent to TPA to cut new panels.

We have ordered 50 fuel tank pump assemblies. These pumps will be mounted to the new fuel tank side access panel. We are working on the protocol for the retrofit of this new fuel pump system. When finished, TPA will ship 16 sets to USA for distribution to those who would like to upgrade.


And here we have the new long wing with slotted flaps installed on the TrueLite in Spain!!! And a look at the improved wing tip. Now just waiting on good flying weather for the test flights.


The TrueLite has electric flaps operating twin telefex cables. The control and flap indicator will be on the instrument panel. Come see this cool ultralight at Sun N Fun this April!!!

And yes, of course the wings still fold in under 2 minutes!

Been two months since I cut the grass. Back to work.


Plenty of News From the Old World

Happy New Year!

I have been in Europe since Thanksgiving now. Working mostly on the Merlin, Merlin Lite, and Merlin II, with a visit to Spain to work on the TrueLite. Kinda looking forward to getting back to Florida for a bit of warmer weather. But I bought a one-way ticket here and am not leaving until my work plan is complete. That work includes refining the designs and making the build specifications perfect. Plus, getting a bunch of parts completed to get builders back on track to complete their aircraft. Then a return trip to Spain to fly the new TrueLite longer wing with flaps that I commissioned to fit Part 103. Here is a sample of some of the work-in-progress:

We have been flying the Merlin with the Vtwin for some time now with the dual fuel pump system mounted on the firewall. It is a serviceable system. And quite similar to the system Rotax and others use for EFI. But it never felt perfect. To me, it seemed convoluted. Fuel hoses from twin tanks to a duplex electronic fuel selector valve, then to two fuel pumps, then to a pressure regulator and fuel filter then splitting again to the EFI rail, plus, 2 lines back to the fuel selector then back to the fuel tanks. We built a circuit board to control the valve and pumps and programmed to automatically switch fuel tanks based on user-selected time or fuel consumption.

This was a lot of work. We should be satisfied with it. But I am not. There had to be a better way. Builder and colleague Ben took a hard look at the way ATVs manage their fuel and found a way to make it work for the Merlin.

This one pump system has everything integrated. High-pressure fuel pump, fuel pressure regulator, fuel filter, and fuel level sensor. It is built to be installed inside the fuel tank. This means that the pump can be much lighter as the fuel to cool the pump is already circulating around the pump. It also means that a fuel return line is not required. Excess fuel from the pressure regulator stays in the tank. No separate fuel filter is required. Same for fuel level sender. This is fantastic! And when we install one in each wing fuel tank, we have redundancy. Plus, all we have to do is turn on or off a fuel pump to switch tanks.

So, how do we make it work for the Merlin tanks?

Here you have it. We dismantle the fuel pump to allow it to fit inside our fuel tank. Then design a mounting bracket to hold it to the fuel tank bottom. Then attach to a side plate for installation, and removal for service, and for the fuel line, power lines, and for sender lines to egress. Then a quick disconnect for easy wing removal.

Currently, Builder Don is redesigning the fuel control circuit board. It will now have a big electronic rotary switch with 5 positions: Off, Left, Right, Both, and Auto positions. And we will make new instrument panels to accommodate this new circuit board with laser-etched labels. Next step will be to design and fabricate a fuel system upgrade kit.

Fuel system side mount prepared in wing tank.

Some of the Merlin changes include a repositioning of the instrument panel so it is slightly smaller. And the avionics tray has a reinforcement stringer, so the avionics are now repositioned. The control circuit board and EFIS are shifted a bit to the right to create room for the headset jacks on the panel. And the circuit board will now include a USB C post for phone charging.

We have the avionics tray and panel in the design office now to CAD up the exact positions so the tray will be pre-punched, and we can install rivenuts for quick and easy component installation. And the wiring harness lengths will then be adjusted to fit perfectly.

Moving on now to the battery. For weight and balance considerations we have moved the battery to the rear baggage bulkhead. For safety, and space, we designed a battery box that hinges on the bulkhead.

In this series of photos, you can see the battery box with built-in hinge and panel cover. The bulkhead has rivenuts to secure this box. The fuselage has plastic tubing routed all the way to the engine and solenoid for the battery cable. The rear fuselage now has two access panels for easy cable connection to the battery.

The cowl has been a big issue for us. You may have seen some of the modifications we have made along the way to get aircraft flying. Not all have been good. But now we are doing it right. We have made a new engine mount, radiator mount, exhaust mount, and component mount for the Vtwin. Now we know exactly how to make a new cowl to fit. Here is how we are calculating the size of the fuel injector bubbles to have adequate clearance. We have to be careful not to have any interference with the injector wires.

We also plan to design an access door for the oil dip stick access. But first we have to redesign the dip stick a bit to clear the engine bracket.


Oil dip stick in progress. Plus, new mounting of engine ECU and voltage regulator.

Next step is the cabin heat cuff and system.

Here you can see the new cuff which will have an air feed from the front cowl below the radiator. Then scat tube connect to a butterfly valve on the firewall center to warm your junk.

Now the cooling system hoses are being 3D modelled so we can send the send out for fabrication for a quick and perfect hose installation.

The cabin air and defrost system will be a separate system from a NACA vent on the fuselage side to the defrost eyeball vent.

A Prague Christmas. Carp for sale on every corner! I pass. And a few days skiing with Davi.

Now back to work, and for Davi, school.









I moved from Aviad in Spain to Tech Pro Aviation in Olomouc, Czech Republic. I have a ton of work to do here as usual as I work side-by-side with Martin on a long topic list. For example:

  • Controlling the next 3 containers of Merlin’s for shipment.
  • Sorting painting specs for next aircraft shipment.
  • Checking 750 and 1450 float production.
  • Working on Vtwin and avionics installation.
  • Making plan to double or triple aircraft production.
  • Working on electric power system for TrueLite and Merlin Lite.
  • Making plan for Merlin Lite testing and compliance documents.
  • Strategic plan for MOSAIC aircraft.

That is just a partial list. I am here until my work is done, but I sure miss Florida weather.

It only snowed twice this week. Once for 3 days and once for 4 days.

I will have a lot to show and report on over the next few weeks of work here. To keep up I will try to post more often. Here is a big post, but mostly photos and in random order.

Here are the 750 float side skins. To build a tool to press the curve into the skins could cost some $2,000. Martin designed a rolling/pressing tool using steel bar and hard-pressed wood to make the same curve but for a cost closer to $200. These skins along with the bulkheads and all the other parts are epoxy-primed on the interior sides. The parts kits will be sent to Paul at M-Squared for assembly. Parts kits take about 10% of the shipping space of assembled floats. And I like to dump more work on Paul…..

Continuing with 1450 floats:

The bigger amphibious floats have many interesting upgrades including a servo to control the water rudders. That saves a lot of rigging. And new hydraulics. More on this later. And Beringer wheels & brakes with improved geometry. Will probably have to write more on floats later.

I often get asked when we will have the Merlin II ready. The answer is about 6 years ago. The Merlin II has been flying and in production for a long time. I just do not promote it in USA as I think 165 of 2-seat LSA models kinda fills the market considering only about 200 are sold each year. Here is a new Merlin II with a Rotax engine mount ready to ship. We offer the Merlin II with yoke or stick control.

Plus, we have the nice Merlin II demo available if someone wanted a Merlin II quickly and at a good price.

Demo Merlin II with Rotax 912 installed.

And for the Merlin Lite fans, here we have a set of short wings getting prepped for painting. They will ship to USA in the next container and be on display at SNF. Now I have to choose to show the Merlin Lite with the long wings or short wings at SNF. One wing set will be on display, the other installed. Or maybe I install one of each on the display Merlin Lite. I wonder if anyone will notice? Or ask if we install to opposite sides for flying in the southern hemisphere? I am not sure I will do this. But it might be fun. Just won’t be doing any flight demos.

Here is one major change that my tall Merlin customers will appreciate. The instrument panel and bulkhead are moved up. I took a photo sitting in the exact same position in a HKS and a Vtwin Merlin. You can see the knee room has nearly doubled. I measured 16cm vs. 12cm. Plus, the firewall shelf and cavity for the Rotax 582 starter motor are gone. This means those pilots with big feet have a lot more toe room as well.

Here are 3 changes on the tail:

  • The horizontal stabilizer installation is changed to the method I used on the SportCruiser: 2 pins for the front then 2 bolts laterally for the rear. That makes installation about 200 times easier.
  • The rudder cables are slightly repositioned and with bigger exit failings.
  • The vertical stabilizer fairing is now taller for increased yaw stability.

Plenty more to show but I need to get back to work!

BTW, I get to visit my son, Davi, in Prague on the weekends. I try not to distract him during exam time, but everyone needs a break once in a while. He is halfway through an electrical engineering/computer science degree.



Some customers claim that I have been slow to deliver. And they would be right. Some claim not only have I been slow but ridiculously and unacceptable slow. They are also right. And the ones that are not claiming that I have been slow are most certainly thinking about it.

I am sure at least a few customers think I have been a jerk. They also would be right.

As a matter of principle, I have always responded to every inquiry about delivery terms. Until just recently, when I ignored some texts as I had nothing new to report and I was a bit frustrated. Hence the jerk mode.

So Whisky Tango Foxtrot?

I believe the Merlin is an exceptional aircraft that fits the needs of many pilots, especially being $100k cheaper than 2-seat LSA aircraft. The Merlin needs to be on the market and available. And it was. But then HKS stopped production. As did Rotax with the 582 however, that engine, although perfect for the Merlin, was not so popular in the USA as it is a 2-stroke.

So, in the interest of keeping the Merlin on the market we came up with the V-Twin idear (redneck for idea). Which, in principle, is an excellent idear and someone should have done it years ago. But no one did. So, I stepped out of my comfort and skill zone and, reluctantly, got into the engine business. It should come as no surprise that I greatly underestimated the effort it would take. Yet I was still surprised.

Those following these efforts know that we have accomplished quite a bit:

  • The engine is custom-built to our specs.
  • Custom radiator, pressure tanks, and molded tubes.
  • Custom fuel system with fuel return
  • Proprietary circuit boards for avionics, engine, and fuel control.
  • Custom wiring harness.
  • Custom reduction drive.
  • Plus, engine mount, exhaust, cowl, and propeller.

But there were issues, some bigger than others.

  • We re-designed the reduction drive with an added bearing.
  • We re-worked the radiator and molded hoses for a better fit.
  • The cowl needed work to eliminate interference with the injectors and one cooling hose.
  • The circuit boards needed revisions.
  • The fuel system is a work-in-progress.
  • The wiring harness had to be designed, tested, then manufactured, and tested again.

When I had an aircraft factory with 250 employees, including a room full of engineers these issues did not take so long to resolve. Now I am mostly by myself and relying on my friends and associates to help when they are not sorting their own work. Not making excuses, just observations.

With the new association with M-Squared in Alabama the build center was just about to ready to ireally get going. However, the Vtwin was not yet ready for prime time. And we didn’t know why. I could fly the Merlin but the engine starting and idling was rough. Not how it should be. We have been trying to sort this for some time. I have been doing test flights but never comfortable with the engine. Bottom line is just that. If I do not truly trust the engine then I am not shipping aircraft. Of course, the planned cash flow budget got torpedoed. But that is my problem.

To figure out what was going on as quickly as possible we built a test stand in Alabama and another in Dayton, Ohio and solicited outside ATV engine experts for support. Why would the engine run well except at low RPMs? We spent a lot of time unwinding and tracing the wiring harness and it appeared to be correct every time.

It took until this week to figure it out! It was Hall of Famer Paul Mather and his team that found the eureka moment. The fuel injectors were getting only 2.4 volts power. They are designed for 13v which we have measured and confirmed in the system and panel and avionics. But way too low at the injectors. Why?

One 4-pin plug was wired in reverse! Simple fix. Engine runs great.

It just took forever to find this. And we are still not sure if the wiring diagram is wrong or the plugs were wiring incorrectly, or just upside down. Does not matter who gets thrown under the bus, it matters that we found and fixed it.

Now we are running the test engine for a few hours for control. We acquired a pin remover tool and will correct all our harnesses. Then we will install and test on two Merlins, one in Dayton and the other in our M-Squared build center. Then more ground testing, then flight testing with 2 Merlins.

And then we are back in the build business. Deliveries to follow. I choose to live with the stress of late deliveries as it is infinitely better than living with delivering a product that hurt or killed someone. I trust you understand.

I am writing this blog now on a long flight from Florida to Barcelona. While Paul continues the Vtwin work I will work side-by-side with Francesco to build the new TrueLite version. I will fly his original prototype then help manufacture the new wing which I commissioned to fit Part 103. A bit longer, wing tips, and flaps included.

I have stuck my nose into Francesco’s design and made a few requests. The wing is longer, has nice wing tips, and electric flaps. This will add a few kg but still under the Part 103 limits and now will mee the Part 103 stall speed. And, IMHO, look nicer and fly better.

So now I have parked my butt in Francesco’s workshop in some little village in Spain for the next week or so. We will build, install, and fly the new wing. Time to get my hands dirty.

Here was my Thanksgiving turkey dinner as I was flying yesterday over the pond:

Clearly, they don’t celebrate Thanksgiving in Europe, except maybe the Brits who were glad to get rid of the pilgrim traitors. Someday ask me about John Alden.

A T-storm over Charolotte forced a ground stop which meant I missed my flight to London. I was lucky to get a later flight out of New York so my travel which still has not ended is Flight Tampa-Charlotte-New York-London, Barcelona then bus to the train to Girona and Francesco’s van to some small village where he chose to set up shop for unknown reasons.

No clue where my luggage went.

I brought my Garmin Virb to capture more video for you viewing pleasure.

The next stop after Spain will be the Czech Republic. The priority is collecting the missing parts builders have been waiting forever for. I will not leave CZ until I have them!

Second priority is inspecting and controlling the next two containers about ready to ship. The timing is not too bad as Paul now can finish the Merlins he has in the build program and make room for the next batch. Plus, one container with 2 Merlins and a Merlin II is about ready to ship to New Zealand.

After that work will be a hard discussion with TPA for the Merlin Lite production. This aircraft is truly exceptional and will be a big market success IMHO. The long wing is a pretty good motor-glider and provides a means for pilots who have ben denied a medical to get back in the air. And the short wing Merlin Lite is a super Part 103 ultralight. We already have lots of orders. The plan is to increase production very significantly by creating an assembly line in Alabama. We just need to get the parts.

Then I need to get the electric power system sorted. An electric-powered long-wing Merlin Lite (The Electrolite) might be a game-changing aircraft. TPA has some expertise in this technology.

The goal is to get all this work finished before the Christmas break. BTW, this was not an easy blog to write. But that is also my problem.


What’s Up Post

A few of my 15 followers have noticed I have not blogged in a while, and they are anxious for news. I have not posted in some time as I am busy making the news to write about. And I usually like to have something significant to write about when I post a new blog. But today, the big news is I am still here busting butt to get aircraft finished and delivered. The last few weeks have been spent in Alabama and Ohio working on the Vtwin installation and getting firewall forward parts sorted. I will write some highlights as I think of them.

The new engine wiring harnesses arrived. Plenty for everybody. We unwound one and traced each wire back to the plug pin number to confirm it is prepared correctly and they are.

Wiring harness in stock!

The reduction drive upgrade parts are also in stock. I have started to ship firewall forward parts out now. But slowly, as I would really like to make the shipments complete. Not quite there yet. As Paul and I work through customer builds we update the working document for the BOM and for the photo guide assembly manual. Anyone wants a draft just e-mail me.

Here is a Vtwin mounted on a test stand in Alabama. We did mount and run a Vtwin some time ago in Dayton. Now we think we can improve our installation with some ECU fine-tuning so we mounted up an engine just as it would be on a Merlin.

Here we have plumbed in a fuel pressure gauge and amp meter to confirm these parameters are in spec.

We are also experimenting with an in-tank fuel pump. Bench testing is promising.

Oh, and 15 instrument panels are finished and shipped to AL. MGL water-jetted the panel then powder-coated them. Then laser-engraved the labels and N numbers for those customers that have N numbers reserved.

News from CZ: The next 7 Merlins and one Merlin II are nearing completion. The Merlin II is already in the paint booth.

Merlin II in the paint booth.

We are flying the Merlin Lite in Alabama now. I will ask Paul to write a flight review so you can hear how great it is from someone less biased than me. I know he likes it. And he is not used to the long glide when power is pulled. We did discover that a mag sensor mount was out of spec by 1/10th of a millimeter. Polini sent us new spacers and now the engine starts perfectly.

My next trip is:

  • The CZ to inspect the next two or three containers of aircraft getting ready to ship. And to make sure TPA has completed my parts order. Some parts for the firewall forward package come from TPA so I will make sure to get them so everyone can get on with their builds.
  • Next stop will be Spain to fly the TrueLite and to nail down delivery of the first kits.
  • Then to India to install floats to a CH601 and fly it.
  • And a quick stop in Myanmar to visit an aviation friend and kind of accomplice in aviation endeavors.
  • And finally, to the Philippines to finish and fly a Merlin there. And help out with a couple M-Squared aircraft that happen to be at the same airpark.

The trip might not be in that exact order. Depends on if I head east or west leaving Tampa. Another time round the world.

Nearly forgot, Builder Don got his wings installed and HKS engine started! Another Merlin will be flying in Dayton soon! Pictured above: Ben, Don, Chip & Ron.

Oh, BTW, I also am expecting 2 more patents this year in the electric aviation field. Patents starting to stack up with four total. More on that later. Some of this work directly helps the Electrolite project. Personally, I think the Electrolite will be a big success.

And, in my spare time, like there is any, I have submitted 3 of 4 proposals for military projects. One to NASA, one to the Navy, and one to the Air Force with a second one for the Air Force in preparation. The topics generally revolve around the technologies in my wheelhouse like the Hyper-STOL aircraft, and amphibious version, and hybrid propulsion systems. I included an autonomous air-to-air refueling technology just for a teaser. This military work helps fund the Merlin R&D and production so winning an award is a good thing for Aeromarine and our customers.



Quick Update

Waiting on the new engine harnesses to arrive. 20 being made up now. Last big item to get. Next time I am in our Alabama build center I plan to box and ship stuff to builders.

The interest in a long wing Merlin continues. However, I am not starting any more projects until we get the Merlin and Merlin Lite orders filled.

But just for a tease:

I sketched these images out some time ago. Maybe it is a good idea? Electrolite first. then maybe Merlin and Merlin Lite folding wings.

The new redrive backplates are finished and in stock. Nicely anodized too.

Merlin Lite #2 is flying in Alabama. It will be N-numbered as a motor-glider.

Here is another irritating sideways video for you. From my phone. And too short to bother editing.

I did try a dead stick landing. Was really strange because after I shut the engine off and the tach read 000 the prop was still really spinning. The clutch is interesting.

Finally, home after a month of driving. Finished a proposal for the Hyper-STOL amphib for the Navy and the parallel hybrid system for NASA.

Dat’s it for now.