Last month I offered to provide “alternate” leveling points for the Lancair IV/IV-P. I have now lost track of who I promised this to, but was able to take the necessary measurements during my just-completed condition inspection:
The leveling dimples on the fuselage firewall joggle (one on each side) are located approximately 3.5” down from the centerline of the top (left and right) engine mounting bolts. The aft leveling point can be re-established at a point 2.4” down the back edge of the rear fuselage inspection panel from the top joggle. I used the joggle as molded into the fuselage for this reference by extending the line of the joggle aft, then measuring down 2.4” along the rear side of the opening. Consider drilling a small hole in the flange holding the inspection plate for future reference.
These should not be considered as accurate/precise as the original dimples molded into the fuselage, but for those who have finished over the original leveling points, these measurements should be within 0.2” of the originals, and will generate a level reference within 0.1 degree over the distance between the front and rear leveling points. I would not use these measurements for determining side to side (roll) level. The installed wings and/or horizontal stabilizer would likely yield a more accurate roll level.
You might consider measuring the rear seat bottom—as an easy to use level pitch and roll reference. My seat bottom is level within 0.1 degrees in roll, and 0.2 degrees in pitch. I recorded this during building, just in case, and can easily level the airplane using a digital level on the seat bottom…one of the few large flat places on my airplane.
Hope this helps!
Bob