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



Merlin Lite Hop and Update

Now that I have moved the Merlin Lite to Florida and mostly recovered from COVID I am finally back in the hangar. This week I installed new windscreen and wing root fairings and reworked the tailwheel geometry. This short hop was to check the handling improvements. I could say I tested the gear on purpose, or that I logged 4 landings not just one. But in the end the tail wheel is greatly improved. As soon as the new temperature monitor arrives I will be back at altitude.

I did manage to fly to the Czech Republic last week and they even let me back into USA. I brought with me a box of parts including some nice fairings to complete the Merlin Lite prototype. This new windscreen fairing replaces my ugly bathtub caulking. Explains why I am not a plumber.

This wing root fairing is a very complex shape. Yet it fits quite well and cleans up the wing joint nicely.

I noticed in taxing in Ohio that the tailwheel was not tracking as well as I expected. I tracked the issue down to the long spring having too much leverage on the mounting structure. I made some modifications to reinforce the fuselage structure with some aluminum angle and to reduce the length of the tailwheel spring about 3 inches. Then I went for a short hop:

The ground handling and take-off/landing handling was greatly improved. But it did nothing for my lousy tailwheel flying skills.

I would be flying however the EMS gauge is not reading the engine temperatures’ properly. I checked the senders and they are fine. I have a new Polini EMS arriving soon and look forward to getting back in the air later this week.

Next videos will have some real flying and should be therefore slightly more entertaining and informative.





Rambling Blog: Too much news…

Good News #1: I have been Covid-free for a month now. But my lungs are still not fully recovered. Every hockey game I play gets a bit better however so I think in some weeks or months I will be fully recovered. At least I hope so. Need to get my blazing speed back. Oh wait, I never had blazing speed. I may be old but at least I am slow!

News #2: More Vtwin engines arrived and look great! First customer collected his engine the week and he will begin installation to his trike in a pusher configuration. I will post photos when available.

Another engine arrives this week to Tech Pro in the Czech Republic. They already have our CAD files and will be responsible for the final details of the Merlin installation such as the exhaust and cowl.

Photos: VTwins arrive to Dayton with another one sent to the Czech Republic for the 2nd Merlin installation and the cowl fabrication. 2nd image is two of three Vtwins. Another VTwin is already in the customers shop. 3rd image is our dual high pressure fuel pump drawing. High pressure for the fuel injection and dual pumps for redundancy. Pumps are in stock and the custom fittings are at the weld shop.

News #3: I am writing this blog while cramped into an economy seat midway over the Atlantic as I am returning from a very productive meeting with Tech Pro in Olomouc. I also got a few new teeth in Prague. I have an excellent dentist there. I know, long way to go for a cleaning but well worth it for quality service at half the price in USA.  But I digress. I had a big agenda for this trip. First off was inspecting the 8 Merlins getting prepared for the next two container shipments. And they look great! I will have happy customers and hopefully zero back-orders. Almost everything is already done.

Merlin QBKs getting ready to ship. Aircraft for the next two containers are mostly finished with plenty more queued up.

Digression #2: I booked my Prague ticket after the December lock down was lifted. But it was reinstated again shortly before this trip. Tourists were banned. That was actually kinda nice. But all restaurants and pubs and most hotels were closed. Only essential shops like grocery stores, gas stations, liquor stores and flower shops were open. Don’t know how flower shops made the list. Never have been essential to me but that might explain a lot….

Most grocery stores also well some small household or office supplies but they were not permitted to sell those items as it would not be fair to the small shops that were forced closed. At the check out my couple of beers were approved but the tape and scissors I needed to box up some parts were confiscated. Malls were open but 95% of the shops in the malls were closed.

Nearly empty mall with a few food court shops open for take-out. Of course the mall cop busted me for not having a mask while drinking my beer. Actually found a better use for the masks….

News #4: The new long wing for the Merlin Lite is nearly done. And as expected it is truly a work of art. Built to withstand + 4 G’s but without an ounce of extra aluminum. The skins will be installed, and the wing set shipped this month in the next container. I look forward to test flying it and comparing performance to the original shorter wing. The span and huge 3-hinged Fowler flap are designed to meet the Part 103 24 knot stall speed and I am quite sure it will. The test is not even at gross weight but with a 170 lb pilot only. This rule was written in the early 1980s when 170 lb pilots existed.

The wing is nearly ready for top and bottom skins and will be shipped with the next container later this month.

News #5: The Merlin Lite video on YouTube has gone viral with over 102,000 views. I just need to watch it another 100k more times…

News #6: The Merlin Lite design is getting updated based on my test flights and design objectives. Here are some sneak peeks:

There is a pretty big design change you can see above if you are paying attention. But by now my 12 readers’ eyes are glazed over.

News #7: That’s not enough already? After the dust settles from this trip, and it warms up some up north, I will fly up to Dayton to finish a Merlin in the build center and prepare the shop for the next container with 4 more Merlins and the Merlin lite long wings. Plus continue the parallel installation we are doing with the Vtwin to the Merlin. But first I need to play some ice hockey to see how the new teeth hold up.


COVID Kai Kicks Aeromarine’s Ass

Not your usual post but 20 days of fighting the Kung Flu is not normal either. I am healthy athletic, and with no underlying conditions yet Covid sent me to the ER. A solid 2 weeks of misery and now just recovering. I will spare you the details.

Let’s talk wings instead!

In the world of light aviation and especially in ultralight aircraft I doubt there has ever been a more sophisticated and beautiful wing as the new long wing for the Merlin Lite. This wing design was made on 3D Catia software. Just to convert to the above Solidworks image took nearly an hour of fast processing time.

Hundreds of unique parts re required as the wing is tapered in 3 dimensions. Flaps and ailerons of course are tapered to match perfectly.

The parts are now complete and the wing is in final assembly. Just to note: Each part has every singe rivet hole punched to final size and that is before the part is formed. It is quite incredible to have hundreds of parts designed, fabricated, and fitted up all near perfection. This is science but the result is this wing is truly a work of art and will be beautiful to see.

Plus of course the huge 3-axis Fowler flap will bring the stall speed down to Part 103 limits yet when retracted result in a very clean and high-aspect ratio wing providing efficient flight.

Now I am recovering I will be back in the Dayton workshop next weekend. And I already booked my ticket to the Czech Republic for January to inspect the next 4 Merlins about ready to ship now. Slots are already filling in the container after that planned for February.

And in VTwin news we have a batch of engines shipping in 2 weeks. First installers getting ready.