A near silent (10 dB) airplane based on a dream I had that comes with a Blackburn 4 (a Deltic Sabre inline-4 with modified cylinders a strong muffler) or a Blackburn 7 (a Napier 7 straight-7 with modified cylinders and a strong muffler) diesel engines.

The 1.5 liter Blackburn 4 produces 40 HP at 3500 RPM while the 2.3 liter Blackburn 7 produces 50 HP at 3000 RPM.

For maximal silence, the aircraft uses a large propeller that rotates extremely slow, barely enough to lift it off the ground. The engine cowling and firewall are thickly lined with the most exhaust-silencing material possible.

I left the aircraft blank so you can customise it with your own paintjob or militarize it.