Service bulletin SB-12-09-26 involves the
landing gear. A bolt length was changed along with an inspection procedure and
included is creating two 3/8" holes in the F-1276 bottom skin on each side
of the fuselage. The purpose of the holes are two fold …. A drift can be placed
up through the holes to tap on the heads of the landing gear bolts to insure
they are fully seated. Plus, the holes can be used to slip a socket extension up
through the hole to make it easier to check the proper torque on the
landing gear bolts. Unfortunately, my bottom skin was manufactured prior to the
holes being added by the factory … so the bottom skin needed to be drilled.
The photo below
shows the drawing for the placement of the two holes that need to be drilled in
both sides of the bottom skin. Also in the top right of the photo is shows the
HW-00003 plugs that are to be installed in the holes after the landing gear is
installed.
Photo of the drill guide in SB-12-09-26 along
with the plans showing already showing the holes and plugs.
Once again Mike’s creeper came in handy to roll
under the fuselage and carefully mark the hole locations. The two hole
locations on the right side were drilled using a tiny drill bit for a lead hole then bumping it
up to #30. A step drill bit was used to enlarge both #30 holes to the required size
of 3/8".
Using a metal ruler to mark the locations for
the two required holes located directly under the right landing gear bolts.
About to use the step drill to enlarge the two
#30 holes to 3/8".
Only got the right side finished because would prefer help sliding the workbench under the fuselage over enough to expose the bottom skin's left side for drilling.
