Rear NACA Ducts

  • Allan 
  • A/C
  • Hours logged: 2

As many others have done, I am adding rear NACA ducts to supply pressurized air to the overhead console.

I used the opening in the forward fuselage skins to make a template. I decided to place the forward edge of ducts approximately 5 rivets aft of the baggage bulkhead. I aligned the horizontal centerline of the duct with the fuselage sill such that airflow is parallel to the duct (which is not quite parallel to the longeron).

I then drilled holes in each corner with a step drill and rough cut the opening with a pneumatic nibbler.

I followed that with a Dremel router bit, then a Dremel sanding drum.

Finally, I cleaned up the openings with small files and emery paper.

It was a bit nerve-wracking to cut holes into a perfectly good tailcone but I’m really happy with how they came out. One more task crossed off the list..