AH-1 Cobra Pilot

Great job!

Well, if the definition of ceramic is, as listed in your link, "an inorganic, non-metallic", that excludes lots of polymers, since they are organic. Seems more like marketing buzzword hype.

How about a picture?

I have had these in my J-model for some time now, and they are holding up well. I have made a few of these for other people. (I should have sanded these more before painting them, but they were a Beta test.) The eyeball vents came from Aircraft Spruce and are aluminum and plastic. They are not cheap, but very good quality. The size and shape of the fixture was made to accommodate these: I used carbon-fiber infused ABS. An acetone-based paint sticks really well and actually strengthens the print. They are attached with the same sized hardware you remove from the old vent covers, so you can put them in place without removing the overhead panel. I also designed another version with a lip that does have to have the overhead panel removed. PM me if you are interested.

I 3-D printed temporaries while I waited for replacements.

How much does he charge?

Yes, I am. I will PM you with the details.

If you do not have the retaining clip over the gear pump handle, your CB will pop once you move the gear handle to the UP position. Obviously, the gear will not go up, either.

Yes. It is too difficult to reach the hardware, otherwise. I do recommend attaching and removing the vent to the adapter prior to installing the adapter, just to ensure it goes in easier once you have it on the ceiling.

They attach with one bolt through the existing hole the old vent assembly uses.

Mine have been working for several years now, so I am reasonably confident they are good. I can make either the vents or the eyeball fixtures. PM me if you are interested.

Just doing the Math gives this engine a Specific Fuel Consumption of 0.345. That is pretty close to a big Cat diesel. If it sounds too good to be true...

This has lots of promise to make turbines cheaper:

In an effort not to repeat myself, look at my immediately previous comment. You will probably find the depictions counterintuitive.

Take a look at the link I included in a previous comment. It is surprising just how much of the airfoil surface has low pressure, even the underside, and just how little has high pressure.