Trimming the 'batman' ears (F22 bulkhead)

I remember the first time I looked at the F22 drawings (before even reading through the plans) and thinking, "what the hell are those tabs sticking above the F22 bulkhead for?!" After reading the plans, it all makes sense... these tabs support the top longerons during fuselage assembly, but are later cut off from the F28 bulkhead forward.



The plans give a template outline to help the build know where to cut; however, I figured it couldn't hurt to cut less than needed and then sand flush after the outside fuselage has been glassed (even wait further until it's time to install the canard so that it can be sanded to the exact contour of the canard airfoil).

On that note, I outlined the cut as follows - a straight line flush with the forward face of the F28 bulkhead. I then drew a horizontal line flush with the top of the F22 bulkhead - and added a 10 degree safety margin. This 10 degree should give me the extra material needed to later sand down flush with the canard.



Close up...


Same on the other side...


Close up...


With all marks made.. it was time to cut! I now understood what other builders were talking about... how it's not easy to bring a saw up to the love of your life and puncture it like a wild beast! Ok... ok... a little dramatic there... but after building up some courage... measuring four... five.. maybe six times... I finally went for it!



 And before I knew it... like pulling a band-aid... it was all over!





The aftermath...



It was now time to blend the top longeron with the F28 bulkhead.... I started out by penciling a reference line to follow...




I then marked a line (hard to see in the pic below - the small red line) about 6 inches aft of the F28 bulkhead... this gave me an idea on how far back I had in order to complete the blend.


See the red line 6 inches aft of the F28 bulkhead... top longeron...


I started out by using a small hand plane to shave the top spruce longerons...


More shaving...


Now I had to fine tune...


So I switched to a metal file...


More fine tuning...


Now I needed finer fine tuning... so I swapped to 80 grit sand paper...


More finer finer fine tuning...



Oooooooo... looking smooooooth... looking reeeeeeal smooooooth!!









Showing the amount of 'dip' on the right side fuselage...


Showing the amount of 'dip' on the left side fuselage...


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