Big Blog Part 2

This blog is about Merlin parts. There is a lot of information to pass on, so the topic gets its own space. Some customers think this has not been a priority. Not true. Some think later customers have received parts before earlier customers. Also, not true. What is true is that this product development has to be done correctly and then properly tested. What is also true is that Aeromarine has next to no cash flow until aircraft are delivered and pressure from customers just adds to my stress but does nothing to get parts any sooner

There are 3 main items to sort:

  1. Fuel system
  2. Engine wiring harness
  3. Avionics
    1. Circuit boards
    2. Wiring harness
    3. Panel

I will update in that order.

The fuel system is of course, critical to get right and has gone through a few variations. Now we have adapted the ATV system into our wing tanks. This looks to be the best and a very elegant system. The pump, filter, pressure regulator, and fuel level sender are all combined into one unit. The pump is in the fuel tank which keeps it cool. The fuel return line is eliminated. This assembly took some time as it needed custom high pressure and molded fuel tubes, custom gasket, and detailed fabrication.

We are in final testing to confirm the installation is leak-free. Then we will get a few Merlins flying to build some test time.

Concurrently, we are preparing plenty of fuel pump retrofit kits and a video for installation for those doing their own build. All Merlins with the Vtwin will have this new system. We did ship a Merlin with the firewall pumps but to be safe, we collected this Merlin from the customer and will make the retrofit in our build center.

Furthermore, the fuel system gets a gascolator and second fuel filter on the firewall prior to the fuel injectors.

Here is a Merlin with a test tank prepared. We actually have prepared this test to confirm the engine wiring harness is correct but also checks the fuel pump. Which brings us to point #2. The engine wiring harness was prepared with one 4-wire plug revered. It took us a while to diagnose this but once found, was an easy fix. In the interim, our harness supplier went out of business. We found another supplier and have plenty of new harnesses in production. Plus, we fine-tuned the wire lengths and wrap lengths. That results in a simple and perfect installation.

Not on the list, but the top cowl needed redesign to clear the fuel injectors as well. And the cooling system tube and radiator mount are fine-tuned for perfect fit.

Plenty of engines are now in our warehouse and plenty of engine wiring harnesses coming to add to those we fixed in our stock. Now on to avionics.

Changing the fuel system means all our fuel circuit boards are trash. New circuit boards were designed fabricated. Now they need to be populated with the components and the microprocessor programmed. Maybe this level of technology added to the development time, but I think worth it in the long run.

The fuel control is now a rotary knob with 5 positions:

Off-Left-Both-Right-Auto level (volume) Auto level (time).

Plus, all the custom cut, powder-coated, and laser-engraved panels are in the trash bin.

Here is what the new panel looks like. Nearly the same as the prior panel but with new fuel system cut outs on the right side. Laser engraving to follow. Engineer Don busy programming and building avionics harnesses.

On the left is a new Merlin installation and the right a retrofit installation. We are making both in parallel in Dayton so we can test the harness on a running Merlin and make the final wiring harness and avionics tray mounting to fit all Merlins.

Last week I was in Alabama getting parts sorted to ship to customers soon.

This week I was in Dayton working on everything above. Next week I will fly to Prague to finish a Merlin for test flying to conform to the UL2 certification protocols. I will also fill a suitcase with those fuel assemblies and other items.

I will return from CZ around the 15th of July and, after a couple days to reset my jet lag, will drive to Alabama and Dayton again to distribute parts and prepare for Oshkosh.

For those attending the show, come visit our booth and see our progress, and visit our Hybrid Pavillion.

And please be assured that the Aeromarine team is doing its’ best to finish the Vtwin powered Merlins perfectly and safely as soon as we can and without compromise. Won’t be much longer!


PS: We are one of the first to have the Starlink Mini. Elon Musk has seen our plan to install this on our hybrid Merlin for the Oshkosh show.