The transit method is the most accurate. Transit
leveling is accomplished by sighting specified points
on the aircraft. Two longitudinal and two lateral
points are used for this method. The reference points
are sighted through a surveyors transit. Figure 9-43
illustrates longitudinal and lateral leveling of an
aircraft using the transit method.
leveling lugs are usually in the nosewheel well. Spirit
leveling lugs are shown in figure 9-44.
NOTE: The leveling lugs should be
inspected for possible damage or misalign-
ment prior to leveling the aircraft. In the
event of damage to the leveling lugs, the
repaired lugs must be calibrated by
cross-reference with the transit leveling
Plumb Bob and Datum Plate
Aircraft that use the spirit level method have
leveling lugs either built into the structure or
provisions for mounting them on the structure. The
This method uses a datum plate or scale mounted
on the deck of a compartment. Provisions for hanging
Figure 9-44.Spirit leveling.