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

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


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

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

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

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

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

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

Don wrote me recently:

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

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

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

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


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

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