Merlin Lite Long Wing Installed

‘Bout time.

But these things take a while. Design, parts fabrication, assembly, fine tuning, shipping, more assembly, installation….

I really love precision matched-hole technology. Rivets mostly just drop into place. The wing spar bolts fit perfectly. Ailerons and flaps connect nearly perfect. I did have to fabricate new flap actuator arms as these huge 3-hinge flaps call for bigger rod ends and push rods.

Have a look:

Drum roll: Hangar roll out – Dayton, Ohio

This is one beautiful wing.

Huge 3-hinge slotted flap. This flap is longer than the Merlin wing! No problem to meet the Part 103 minimum speed.

Note the two pitot tubes. Top one is for the EFIS. Bottom one is angled down to be more accurate at high angles of attack and is plumbed to the more sensitive analog ASI. Panel photo shows temporary mounting of the analog ASI for the flight test program.

Clarifications for my other reader:

  • There will not be a cowl on this prototype. The production Merlin Lite has the Polini 303DS and is tricycle gear and slightly different engine position. The production Merlin Lite has a cowl. The design is already finished.
  • Initially, all Merlin Lites will be tricycle.
  • Straight floats will be built later this year. I have built many sets in the past. They weigh only 30 lbs. each and fit the Part 103 rule. With the long wing the Merlin Lite will be EXCELLENT on floats! I already bought the wind sock for my seaplane base.
  • We are already planning the electric-powered version of the Merlin Lite. And yes, there will be an electric Merlin Lite floatplane.

I will post videos of the flight tests but it will be a while before I will have time to edit all the footage and make a proper video. I suppose I could post some stills to show it does fly. Watch this space.



Merlin Lite Weight

As we progress with the Merlin Lite development we will be collecting data for our ‘self-certification’ documentation. The Part 103 rules are pretty simple. Stall speed, top speed, single-seat, 5 gallons fuel maximum and 278 lbs empty with a rescue chute. Of course we will be conducting a lot more tests than that to be sure we have a structurally sound aircraft with no untoward flight characteristics.

On that note I have been flying between thunderstorms. I made some selfie videos and finally asked a professional to make proper edits so I don’t torture my 13 followers more than I already do. But now we wait for someone else to do their work…..

We obtained one scruffy bit of paper yesterday with an official DAR weighing with certified scales.

Our prototype Merlin Lite is legal at 271 lbs. The fuel was drained but perhaps one pound of unusable fuel remained in the tank and lines.

Recall that this weight INCLUDES hydraulic brakes, EFIS, EMS, windows, windscreen, electric trim, 3-blade prop, liquid-cooled Polini 250DS engine, large tires, and fuel system with fuel sender.

When we have the production Merlin we will be adding the extra weight of the long wings, cowl, and the tricycle gear. And subtracting some weight from the main gear leg, removing the two top windows, and cutting a few pounds from the engine mount. Plus the new Polini 303DS is 2 kg lighter than the 250DS.

As we finalize options we will post the cost and weight of each item. I know from the DAR who has weighed a few ultralights, and from other ultralight manufactures that most ultralights are over the limit. I also am sure that some of our customers will order options like painting, cabin heat, spinner, 2nd fuel tank, and autopilot. I don’t think they have much risk of a a FAA ramp check as they won’t be on ramps, and the FAA does not carry scales with them. They might check more obvious items like the number of seats and fuel capacity.

As long as it looks like a duck and flys like a duck it must be a duck…..

Next week I return to Dayton to begin flight tests with the new wing. I am sure about our stall speed compliance. It will be fun to document it. I have a few Garmin VIRB cameras with telemetry built in plus a purchased a second ASI that should read lower airspeeds than the EFIS. And a 2nd pitot tube that I will mount more directly in line with the airflow at high angles of attack. All this should make for some entertaining video clips. And more scruffy bits of paper for my compliance file.

Here is our DAR report:

Merlin Lite Official Weight

We remain on track to offer an electric Merlin Lite before the end of 2021. Plus the design of the 750 straight floats for the Merlin Lite are finished and the floats will be manufactured later this year. The long wing electric Merlin Lite on floats is on my wish list.


In other news the VTWIN project rolls along. We have secured our own production run of engine made to our specifications. A significant number of Vtwin engines will arrive around the end of July. Reduction drives and matching propellers are also in production.

The installation to the Merlin moves forward with the engine mount, exhaust, cooling system, and cowl pretty much done. The mold for the cowl is now commissioned. We expect to have cowls from the new mold by the end of July. Here are some VTWIN images:

Oshkosh approaches and, if Sun N Fun was any indication, Oshkosh will be a big event this year! We will have the prototype Merlin Lite there and a Merlin, and a Merlin kit with a VTWIN and maybe a couple of surprises. I am not making any promises just yet as not everything gets done in time especially with all the COVID excuses. I can’t even rely on freight companies and will drive the Merlin Lite to Dayton and then Oshkosh myself.








Merlin Vtwin Installation Update

In my 41 years in aviation I have seen a lot of failures, and learned from them (I hope). One of the most famous ones is the Bede 5 with thousands sold with no suitable engine forthcoming. The Merlin has had plenty of good engine choices. Until HKS stopped production and Rotax plans to discontinue the 582. Hence our efforts beginning about 2 years ago to source or develop a 4-stroke alternative. And it wasn’t easy. But Aeromarine has an extensive and worldwide network of resources and we were able to secure a custom-built engine to our specifications direct from the factory in China. And have a reduction drive built to our specs to match this engine from India. Then have a computer-matched 3-blade carbon ground-adjustable prop with spinner designed and made for us specific to the Merlin’s speeds and this engines’ torque curve from Slovakia. All integrated to our Merlin made in the Czech Republic.

Nearly every customer with a new Merlin order has placed their faith in our experience and abilities to complete this project with the results of a new, very modern and reliable and even inexpensive 4-stroke powerplant perfect for the Merlin. And quite a few new customers have stepped up and placed their order knowing we have not even flown this Vtwin on the Merlin yet and have not even finished the installation.

And I do not intend to let them down.

I have seen a lot of new aircraft designs come on the market over the years and am quite sure that their likely-hood of long-term success is inversely proportional to their advertising budget. Am I right? I think so. There is another new LSA on the market last year with a huge advertising budget. Who wants to bet they are in business a year or so from now?

That being said, Aeromarine spends its marketing budget on getting things done in the shop. And right now the two big priorities are to build Merlin Lites and to finish the Vtwin installation to the Merlin within the next month. And we are on track to do so. Here is how it will look:

The design work is mostly done now and we are busy making the actual installation to a finished Merlin kit. The cowl mold will be cut and all the bits and pieces fitted perfectly. Then we flight test. Then we ship these firewall forward packages out to Merlin builders.

As this is a short blog I will share these photos of a finished and painted Merlin shipping soon for your viewing pleasure.

Another container of Merlins ships in a week or so. Container #3 is almost full.

Guess I am not the only one that flys a single-seat aircraft for the quality of the social experience.







Greetings from Prague

Well not really, I was in Prague Sunday morning and playing hockey in Tampa Sunday evening. Had to plan that flight carefully. Not like the flight to Prague. I was all prepared with a negative test plus positive for anti-bodies inside the 72 hour window the Czechs mandated. But I was not allowed to board the aircraft in Tampa because of my 45 minutes layover in Frankfurt and their specs are 48 hours. My test was a day too old and the Tampa airport testing site closed 20 minutes before I got there. Entire trip cancelled. Rebooked for later in the day after chasing to a quick off-airport test then routing through Amsterdam.

Finally arrived to Prague with my “OFFICIAL” letter from my dentist requiring an urgent cleaning. Then off to Olomouc to visit Tech Pro and inspect the next container of aircraft already nearly ready to ship.

The Czech Republic partially opened up in December and everyone went to the pub then to grandmother’s house for Christmas carp. The result was the virus when viral with 10x greater infection rate than the rest of the EU. I was there in January and the lockdown had just started. This May trip was even tighter locked down. Need to know where you can buy a beer through a window and drink it in an empty garage. Modern Speakeasy. Note the lack of tourists. The hotel I stayed in had not seen a USA passport in a year.

On to airplane business:

The Vtwin installation to the Merlin is moving ahead on track and should be done and ready for flights in a month.

We have pulled a finished Merlin from the supply chain to make this installation. The exhaust is being fabricated now. Fuel system is pretty much done. Cooling is a Rotax 912-sized radiator. All getting mounted up then the cowl mold will be cut.

Merlins: Container #2 for 2021 is just about ready. Some final installations and it will ship in about a week.


Some samples from the next container of quick-build kits.

Merlin Lite: The Merlin Lite design changed so much from the prototype that it is nearly a new aircraft. Tricycle gear, longer wing, all push-rod controls, more leg room. Now parts are being fabricated. It is a huge push to finish the first Merlin by about the 15th of June to ship in time for the Oshkosh show. But we are going to try. The paint can dry in the container.

Not much to show but I did manage to bring the new long wing wing tips with me carry-on. 2 of the new Polini 303DS engines are in transit to Tech Pro.

Next week I will go to Dayton to complete some tests in our lab then crate and ship to Florida for the flight testing finally!

4 Covid tests in 10 days plus positive for anti-bodies. I think I am safe. For now.








Container #1 Arrived! And other dribble

Finally. Good timing too, right after SNF show.  I was able to get up to Dayton to meet and unload the container and get the kit deliveries started.

It was a real challenge to get this container shipped. The container ships were full. Then the dock workers were overload or understaffed or just plain Covid worn out. Once the container arrived to USA I expected more of the same. Delays at Newark off loading then delays to the train. Then delays at customs. Then delays on truck from Columbus to Dayton. I was really surprised the USA side of this shipment went flawless and quick and exactly as quoted. Shocking.

Unloading the container and filling the hangar. And I know NOTHING about the Czech beer we found by accident. But there might be a pattern….

And here they go to points all over!

Some big news for those Merlin Lite followers/customers: The new long wing arrived and it is perfect!

The wings are now in our Dayton R&D lab and will remain there a couple weeks for testing before shipping to Florida for installation to the Merlin Lite prototype and finally some fun flight testing! That new flap is longer than the Merlin wing!

Also arriving over SNF were 5 more reduction drives for the Vtwin program. There is huge interest and many orders for this new engine. Big gap to fill with HKS out and the 582 being 2-stroke and pending discontinuation by Rotax. Now we have the fuel system, cooling system, exhaust, and redrive all sorted.

Now I am back in Florida. Barely. Couple days after I left Florida last week my daughter Lilly tested positive for Covid. So I had direct Covid exposure before I flew up to Dayton. Try to follow this story. There will be a quiz later:

I had Covid really bad in November/December. I figured I am good now full of anti-bodies. Wrong. After 3-4 months the antibodies wimp out. So maybe I could have caught it from Lilly before I left for Dayton? Better check. Tuesday I subjected my finger to a pin prick and tested for antibodies. And I had two. Meaning lgG and lgM antibodies. WTH? Turns out there are short-term and long-term antibodies. But not long long term antibodies. Bottom line is my November antibodies were gone and I had Covid between 2 and 4 weeks ago. Again. And I didn’t even know it.

My Wife was really sick about a month ago and had a lot of Covid symptoms but tested negative. We are convinced she had Covid. And passed it to me. And although I thought I was exposed to Lilly’s Covid I probably gave it to her. It explains the gap between Jana’s and Lilly’s Covid.

So now what? I need to meet colleagues at our lab. I need to fly back to Florida. I need to play hockey. I don’t need to be a super spreader. So I got tested. Again. Negative. Oh the drama.

My girls are OK!

Oh forgot, this is an airplane blog. So Monday I fly to the Czech Republic to inspect container #2, to check on Vtwin to Merlin installation to check on Merlin Lite production, and to plan deliveries for all the new orders from SNF and after.

But of course there will be more Covid drama with the Czech still mostly locked down. Good thing for the ‘official’ letter I have from my dentist requiring my travel for an urgent and vital teeth cleaning.

Next report from Olomouc!







Sun n Fun

I am conflicted. 6 day air shows in the Florida heat, wind, ants, and sun are a marathon. Plus I actually have to talk to people. Yet this year I was actually looking forward to the show. At least for one day. Would anyone show up? Would the mask police be out with batons? Would it rain like cow piss on a flat rock all week?

Apparently, the risk of sunburn was greater than COVID. I doubt too many people went home with sun tan lines outlining the face mask. The show felt pretty normal. I only saw one guy with a full HEPA/charcoal respirator. Pretty sure his mask outline will be permanent.

As usual, the show promotors claimed record numbers in attendance. Rubbish. But still good numbers and I am sure a qualified success. Our booth had steady traffic and huge interest in both Merlin aircraft and the Vtwin. Our message and offer of price vs. performance and value is gaining a lot of traction. We are filling containers as fast as we can now. And we have new orders from the show which is not how we judge show success but it sure helps.

So enough with the babble and on to content. MERLIN LITE NEWS:

  • CAD work is 98.72% finished and parts production has begun.
  • Assembly will begin in May. But I cannot say for sure when the first new Merlin Lites will be finished. I will go to CZ in a week or so to plan these details. I really need one shipped in June for the Oshkosh show but that will be tight.
  • The list of features the Merlin Lite has over most ultralights is already impressive. Add parking brake to it.
  • New images:

Ignore the wheel pants. We are not going for speed in an ultralight. Although they can be added for looks if anyone wants.

Ignore the 2nd wing tank. The wing is built for two tanks but one will be just a wing nose skin cover. For those who need 8 hours endurance the wing tank can be added but it will put the aircraft outside of the Part 103 limits.

The new wing with the huge flaps is already finished and shipped. This Friday I fly to Dayton to meet the container of Merlins which also has this wing packed. We have some bench tests to conduct then I will ship the wing to Florida for installation and then flight tests on our Merlin Lite prototype. I have been preparing for accurate data collection with the purchase of dozens of cones and a long tape measure for runway marking and more Garmin Virbs for multiple video angles and telemetry data. This will be fun.


HKS is gone. Rotax plans to discontinue 582 production. The Vtwin has a big gap to fill and it will do it very well with such a modern and well-tested engine.

We had our first customer-installed Vtwin on display on a PPG trike. The customer has it running already. The reduction drive shipment arrived to Dayton during the show so no chance to have them on display. But soon we will be flying. Two Merlins have Vtwins in installation now for our testing and documentation. Fuel system, exhaust, engine mount, and cooling are mostly finished. Wiring harness in design. We may move to an electronic throttle.

Not shown is the racing muffler from motorcycles which attaches to the stainless steel exhaust tubes.

The Vtwin generated a LOT of interest at SNF with plenty of aircraft needing a 4-stroke 60hp engine.

I am really looking forward to Oshkosh. Kinda…….


Sun N Fun Prep

Sun N Fun starts Tuesday and runs through Sunday. Aeromarine booth is way out in Paradise City away from any contagions besides great aircraft. I know at least one blog reader plans to attend. The other one is stuck on the other side of the pond.

Lets start with the Vtwin news. We painted the display stand and added wheels! But even more impressive is the exhaust system is getting finalized. Custom welded stainless steel pipes shown above feed into a racing muffler (not shown). Will be quiet and efficient.

The first batch of reduction drives was shipped weeks ago and finally arrive to Dayton the day before the show starts. We have to FedEx a couple sets down to display. After the show this engine will be delivered to customer #2 with prop and redrive and radiator.

Customer #1 has made his first engine runs and will have his engine and trike in our booth at SNF.

I was in Dayton last week waiting for a container of Merlins but they won’t arrive until after the show. This container has the new Merlin Lite long wings in it too!!

I managed to load the BRS rocket fuel without any drama so my rocket scientist heritage pays off (My Dad was a member of the American Rocket Society). Above is an installation of a BRS 800 to a Merlin going overseas soon.

The next container is ready for shipping so after I return to Dayton to unload and deliver these Merlins it’s off the CZ for another inspection. By then lockdowns will be lifting so maybe I can get a real beer in a real pub. Don’t tell anyone but I might have smuggled a few Budvar original Czech beers inside one of the aircraft. I better make sure to unpack before the customer gets excited.

Won’t arrive in time for SNF show. Sigh.

Here is one beautiful Merlin getting ready for container #2. It will get the last HKS off the production line. There are several Merlins finishing soon and a couple of them or more plan to attend Oshkosh in July. My booth will be packed!

In Merlin Lite news I have been practicing touch & goes. I repositioned the radiator and cooling is almost too much with temperatures just in the low end of green. Climb is around 500 FPM. Cruise matches RPM with 70mph at 7,000 and 60mph at 6000. Full flaps provides a nice steep approach and touchdown under 35 mph. After SNF I will be making more accurate measurements of all parameters then swapping out to the long wing for comparison. I hacked together a lousy video for those who like abuse:


I had a request to measure the Merlin Lite panel for an 11 inch iPad. Looks like an easy fit with only one fuel gauge and some other minor adjustments. I could really use Foreflight for my cross country tomorrow to Lakeland SNF show. After all it is nearly 4 miles!






More Barely Significant News

Today I flew the Merlin Lite. Finally better weather, kind of. MVFR with 1,300 foot ceilings. Perfect for an ultralight to make a few laps around the pattern so that’s what I did. My taildragger skills (or lack of) can always use the practice. I noted the climb was around 500 FPM. Cruise was about 65 mph at 6,500 RPM. The real test was the cooling. I remounted the radiator lower and more directly into the airflow with excellent results and temperatures at the bottom of the operating range for the Polini.

The flaps at 40 degrees were very effective. And I managed not to ball it up on the landings. All good. Tomorrow I expect better weather and will make some video. But not to leave you hanging there is a new video posted on the Experimental Aircraft Channel. Apologies in advance as it was my worst interview. I just don’t have all the data yet so I cannot state facts, just expectations. I cringe to share this but you will probably find it anyway as my other reader would share. Over 10k views already! My other reader must have watched it over and over….

Now I am even more motivated to collect the data. The new wing is shipped and arrives the week before SNF. I do not think I will manage to get it to the display. I will be in Dayton to unload the container and at least will bring photos.

Read Merlin Lite March 2021 SportFlying story here.

VTwin News:

The first trike pusher installation is moving forward quickly. This trike will make the trip from Ohio to SNF for display in our booth. Plus we will bring another Vtwin with our custom carbon prop for display.

Our first batch of reduction drives has shipped from India this week. We will have these mounted and on display at the show as well.

And last but should be first is builder Randi is back in the air with his Merlin taildragger. We upgraded his muffler to the new style we will use on the Vtwin. He seeing 100 mph indicated at only 5,300 RPM on his HKS.

Watch this space for move video links soon. I have to prepare for my first Merlin Lite cross country flight to the Sun n Fun show.


Quick update

Here is your periodic news brief:

Another 4 Merlins are in a container and on a ship to USA currently. Plus the new Merlin Lite long wing is finished and shipped in this container. There is a slight chance I can get a wing from Dayton down to the Sun n Fun show starting April 13th if the container is not delayed more than it has already. Work is far along on another container of 4 Merlins expected to ship next month.

The series of cold fronts with rain and winds are diminishing. I managed to squeeze in a dawn patrol flight very early last week. The video is edited as I did not actually do any real flight testing. I just wanted to get back in the air.

The Merlin Lite tricycle gear model design is now finished. Parts are in production and assembly of the first batch of new Merlin Lites with the long wing, tricycle gear, and Polini 303 engine with cowl will be in assembly soon.

Once production and deliveries are sorted I can turn my attention to the electric-powered Merlin Lite and also the 750 floats which will match up perfectly. Lots going on and 2021 looks to be a really great year for the Merlin line of aircraft.


Bad Weather Blog

I usually don’t write blogs when there is little to report. But one of my 13 followers thought covid did me in. Not just yet. And here is proof: A rambling blog.

Last trip to Dayton was 5 days of snow and cold with no flying. Day 6 was sunny and clear but hangar door was frozen shut.

Good thing we have our Florida center. Except for the last 2 weeks of crap weather here too. Maybe this weekend I can get the Merlin Lite back in the air. The new engine monitor arrived and proves the one installed has a faulty temperature reader.

Replacement gauge is below and shows correct information tested for both CHT and water temperature.

In even more boring news we have molded a pick up for the new Whelen Blaze LED wingtip position lights with strobes.

Next 4 Merlin quick build kits arrive to our Dayton build center 1st week of April. Just a few days before I need to be in Florida for the Sun n Fun show.

The 1st Merlin Lite long wing will be in this container. I will bring it to our SNF booth. I doubt I will have enough time to flight test it prior to the show and I prefer not to conduct flight tests at shows. Not a good practice. So expect to see the Merlin Lite prototype in the booth with the long wing on display.

Sneak Peek