22
Drill Bottom Fitting Holes
Center the bottom fitting with the strut cen-
terline clearly seen to be going through the center
of the holes. MAKE CERTAIN THE LENGTH-
WISE POSITION IS CORRECT AS INDICATED
BY THE LINE PREVIOUSLY MARKED ON
THE FITTING.
Clamp tightly and recheck alignment.
DOUBLE CHECK THAT THE FACE OF THE
FITTING IS PARALLEL TO THE FLATS INSIDE
THE STRUT.
Be careful
: it is very easy to clamp
the fitting at a slight angle on the strut because of
the curved surfact. So, before drilling any holes,
check and double check that the fitting is parallel to
the flats. Otherwise, your first holes will be at a
slight angle, which will result in a twisted strut that
can’t be installed on the airplane.
Use two clamps to hold it in place, leaving
access to the hole closest to the outboard end of the
fitting for drilling.
Drill the first hole THROUGH ONE SUR-
FACE ONLY, NOT THROUGH THE ENTIRE
STRUT, and put a bolt through the one side and
reach in side to put a nut on it. Snug it down.
An alternate approach is to use a drill press
to drill the first hole, BUT IT IS CRITICAL
EVERYTHING BE SET UP SQUARE! Level the
drill table and level the strut exactly.
When drilling these holes, use a fresh bit
and let the bit do the work and let the fitting guide
the bit. Don’t force it.
Recheck it for alignment, re-clamp and drill
the last hole inboard. Put a bolt in it and snug it
down.
The bottom fitting is now secured with two
bolts and we can do the top fitting.
Drill Top Fitting Holes
As a last minute check to make sure nothing
moved, put the strut back up on the airplane with
the bottom fitting bolted to the outside of the strut
and the top fitting still clamped to the outside.
RE-CHECK DIHEDRAL M E A S U R E-
MENT. This is the last chance you’ll have to cor-
rect anything.
Re-check the line you drew across the top
fitting. If it’s not right, correct it.
Remove the strut. Center the outside fitting
hole over the centerline that you marked lengthwise
on the strut making certain the fitting doesn’t
change position lengthwise, as indicated by the
Once one bolt hole is drilled square and the fitting bolted in
place on the outside, the rest of the holes may be drilled
through ONE SIDE OF THE FITTING ONLY. By using the fit -
ting as a drill guide, there is little opportunity for the holes to
be anything but square to the surface.
The top fitting with one hole drilled and bolted. The bottom fit -
ting is aligned along the centerline but the top one has a slight
angle, so it is better to attach it to the wing, as shown, careful -
ly mark it, AND CLAMP IT FIRMLY, then bring it down and drill
the other holes.
It is not necessary to use a drill press to drill the holes all the
way through the strut. In fact, it is highly advisable that a
clamp be placed between the two outboard holes and tight -
ened as much as possible. With locating bolts in the outboard
holes, this guarantees that the fitting squares up with the flats
inside. Then, when the two outside holes are drilled and bolt -
ed, they hold the fitting square so the balance of the holes can
be through-drilled.
Summary of Contents for Bearhawk N33RB
Page 1: ......