Drill Lower Longerons

Today I drilled the lower longerons. These are the 8 AN3 Bolts which attach the longerons to the lower engine mount. Again this is important as this holds the engine to the plane.

Here is a couple of shots of the task before I begin.


another angle for clarity.


First mark the proper locations behind the firewall.


Used the punch to mark out the lateral location. This must be done exactly correct to maintain the proper edge distance for the holes.



Drilled all holes with a #40 bit.


Up-sized to AN3 (#12)


And repeat on the opposite side.