Firewall Assembly Countersinking

The final step before riveting the firewall is to countersink all of the parts that rivet to the back of the firewall (to accept the dimples).

This was a simple enough task, just lots of countersinks.

I also got started on the forward fuselage ribs (the front of the tunnel). Most of the holes were final sized on these parts but I had to final size the powder coated nose gear tension fittings.

The only other holes that needed final sized were the nutplate screw holes. I upsized these #19.